Samacheer Kalvi 11th Computer Applications Guide Chapter 1 Introduction to Computers

Tamilnadu State Board New Syllabus Samacheer Kalvi 11th Computer Applications Guide Pdf Chapter 1 Introduction to Computers Text Book Back Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 11th Computer Applications Solutions Chapter 1 Introduction to Computers

11th Computer Applications Guide Introduction to Computers Text Book Questions and Answers

Part I

Choose The Correct Answers

Question 1.
First generation computers used _________.
a) Vacuum tubes
b) Transistors
c) Integrated circuits
d) Microprocessors
Answer:
a) Vacuum tubes

Question 2.
Name the volatile memory _________.
a) ROM
b) PROM
c) RAM
d) EPROM
Answer:
c) RAM

Question 3.
Identify the output device _________.
a) Keyboard
b) Memory
c) Monitor
d) Mouse
Answer:
c) Monitor

Samacheer Kalvi 11th Computer Applications Guide Chapter 1 Introduction to Computers

Question 4.
Identify the- input device _________.
a) Printer
b) Mouse
c) Plotter
d) Projector
Answer:
b) Mouse

Question 5.
_________ Output device is used for printing building plan, flex board, etc.
a) Thermal printer
b) Plotter
c) Dot matrix
d) inkjet printer
Answer:
b) Plotter

Question 6.
In ATM machines, which one of the following is used _________.
a) Touch Screen
b) Speaker
c) Monitor
d) Printer
Answer:
a) Touch Screen

Question 7.
When a system restarts, which type of booting is used?
a) Warm booting
b) Cold booting
c) Touch boot
d) Real boot
Answer:
a) Warm booting

Question 8.
Expand POST _________.
a) Post on self Test
b) Power on Software Test
c) Power on Self Test
d) Power on Self Text
Answer:
c) Power on Self Test

Question 9.
Which one of the following is the main memory?
a) ROM
b) RAM
c) Flash drive
d) Hard disk
Answer:
b) RAM

Question 10.
Which generation of computer used IC’s?
a) First
b) Second
c) Third
d) Fourth
Answer:
c) Third

Part – II

Short Answers

Question 1.
What is a computer?
Answer:
It is an electronic device that processes the input according to the set of instructions provided to it and gives the desired output at a very fast rate.

Question 2.
Distinguish between data and information.
Answer:
Data:

  • It is an unprocessed collection of raw facts.
  • It will not give any meaning.

Information:

  • It is a collection of processed facts from which conclusion may be drawn.
  • It convey meaning.

Samacheer Kalvi 11th Computer Applications Guide Chapter 1 Introduction to Computers

Question 3.
What are the components of a CPU?
Answer:
The CPU has three components. They are:

  1. Control Unit
  2. Arithmetic and Logic Unit
  3. Memory Unit.

Question 4.
What is the function of an ALU?
Answer:
The ALU performs operations such as addition, subtraction, multiplication, division and logical operations.

Question 5.
Write the functions of control unit.
Answer:
The control unit controls the flow of data between the CPU, memory and I/O devices. It also controls the entire operation of a computer.

Question 6.
What is the function of memory?
Answer:
The memory is used to store the data for processing and for future reference.

Question 7.
Differentiate Input and output unit.
Answer:

  1. Input unit is used to feed any form of data to the computer for further processing.
  2. Output unit conveys information to users in an understandable form.

Question 8.
Distinguish Primary and Secondary memory.
Answer:

  1. The primary memory is used to temporarily store the programs and data to execute currently. It is volatile in nature.
  2. The secondary memory is used to store the data permanently. It is non-volatile.

Part – III

Explain In Brief

Question 1.
What are the characteristics of a computer?
Answer:
Characteristics of Computer:

  1. Speed : Very high speed i.e. more than 10-12 second.
  2. Accuracy : Very high accuracy even with high speed.
  3. Storage : Computer can store any volume of data for a long time.
  4. Diligence : Computer can work for hours without any break and creating error. It is suitable for repetitive jobs.
  5. Versatility : Computer can perform variety of task.
  6. Power of remembering : It can remember data for us.
  7. No IQ : Computer itself having no thinking power. It works based on the given instruction.
  8. No Feeling : Computer does not have emotions, knowledge, experience, feeling.

Question 2.
Write the applications of computer.
Answer:
The various applications of computers are:

  1. Business – It is used in. business for Payroll preparation, Sales analysis, Budgeting, Financial forecasting,
  2. Managing employees database and Maintenance of stocks etc.
  3. Education – It is used for online teaching with CBTs and WBTs.
  4. Marketing – It is used for Selling & Promoting product.
  5. Banking – It is used for Home banking with internet, ATM etc.
  6. Insurance – It is used to transact insurance operation.
  7. Communication – Email, chatting etc,
  8. Health Care – ECG’s, radiotherapy like monitoring devices.
  9. Military – It builds the links between the soldiers and commanders through the satellite.
  10. Engineering Design – Machine design, building plan, Interior design etc.

Question 3.
What is an input device? Give two examples.
Answer:

  1. Input device is used to feed any form of data to the computer for further processing.
  2. Keyboard – To feed text, numbers, special characters etc..
  3. Mouse – Pointing device i.e. to select an item on the screen.
  4. Bar Code Reader – Scans the information on the bar codes transmits to the computer.

Question 4.
Name any three output devices.
Answer:

  1. Monitor – To display the information.
  2. Printer – It is used to print the information on papers.
  3. Plotter – It is used to produce graphical output like building plan on paper.
  4. Speaker – It produces voice output.

Samacheer Kalvi 11th Computer Applications Guide Chapter 1 Introduction to Computers

Question 5.
Differentiate optical and Laser mouse.
Answer:
Optical Mouse:

  • It uses light source instead of ball to judge the motion of the pointer.
  • It is less sensitive towards surface.

Laser Mouse:

  • Laser Mouse uses Laser Light.
  • It is highly sensitive and able to work on any hard surface.

Question 6.
Write short note on impact printer.
Answer:
The impact printers print with striking of hammers or pins on ribbon. These printers can print on multi-part papers. Dot Matrix printers and Line matrix printers are impact printers.

Question 7.
Write the characteristics of sixth generation.
Answer:
The characteristics of sixth generation computers are:

  1. Parallel and Distributed computing
  2. Computers have become smarter, faster and smaller
  3. Development of robotics
  4. Natural Language Processing
  5. Development of Voice Recognition Software.

Question 8.
Write the significant features of monitor.
Answer:
Monitor is the most commonly used output device to display the information. Pictures on a monitor are formed with picture elements called Pixels.

Monitors may either be Monochrome or can be color.

Types of monitors:

  • CRT (Cathode Ray Tube)
  • LCD (Liquid Crystal Display)

Part – IV

Explain In Detail

Question 1.
Explain the basic components of a computer with a neat diagram.
Answer:
The computer is the combination of hardware and software. Hardware is the physical component of a computer while software is the set of programs or instructions. Both hardware and software together make the computer system to function. Every task given to a computer follows an Input- Process- Output Cycle (IPO cycle).
Samacheer Kalvi 11th Computer Applications Guide Chapter 1 Introduction to Computers 1
The functional components of a computer:
(i) Input Unit : Input unit is used to feed any form of data to the computer. Example: Keyboard, mouse, etc.

(ii) Central Processing Unit: CPU is the major component which interprets and executes software instructions. It also controls the operation of all other components such as memory, input and output units. The CPU has three components which are Control unit, Arithmetic and logic unit (ALU) and Memory unit.

(iii) Arithmetic and Logic Unit : The ALU is. a part of the CPU where various computing functions are performed on data. The ALU performs arithmetic operations such as addition, subtraction, multiplication, division and logical operations.

(iv) Control Unit : The control unit controls the flow of data between the CPU, memory and I/O devices. It also controls the entire operation of a computer.

(v) Output Unit: An Output Unit is any hardware component that conveys information to users in an understandable form. Example: Monitor, Printer etc.

(vi) Memory Unit : The Memory Unit is of two types which are primary memory and secondary memory. The primary memory is used to temporarily store the programs and data when the instructions are ready to execute.

The secondary memory is used to store the data permanently. The Primary Memory is volatile, that is, the content is lost when the power supply is switched off. The Random Access Memory (RAM) is an example of a main memory.

The Secondary memory is non volatile, that is, the content is available even after the power supply is switched off. Hard disk, CD-ROM and DVD ROM are examples

Question 2.
Discuss the various generations of computers
Answer:
Samacheer Kalvi 11th Computer Applications Guide Chapter 1 Introduction to Computers 2

Question 3.
Explain the following
a) Inkjet Printer
b) Multimedia projector
c) Bar code / QR code Reader
Answer:
a) Inkjet Printers: Inkjet Printers use colour cartridges which combined Magenta, Yellow and Cyan inks to create color tones. A black cartridge is also used for monochrome output. Inkjet printers work by spraying ionised ink at a sheet of paper.

The speed of Inkjet printers generally range from 1-20 PPM (Page Per Minute). They use the technology of firing ink by heating it so that it explodes towards the paper in bubbles. An Inkjet printer can spread millions of dots of ink at the paper every single second.

b) Multimedia Projectors : Multimedia projectors are used to produce computer output on a big screen. These are used to display presentations in meeting halls or in classrooms.

c) Bar Code Reader: A Bar code is a pattern printed in lines of different thickness. The Bar code reader scans the information on the bar codes transmits to the Computer for further processing. The system gives fast and error free entry of information into the computer.

QR Code Reader : The QR (Quick response) code is the two dimension bar code which can be read by a camera and processed to interpret the image

Samacheer Kalvi 11th Computer Applications Guide Chapter 1 Introduction to Computers

11th Computer Applications Guide Introduction to Computers Additional Important Questions and Answers

Part A

Choose The Correct Answers:

Question 1.
Who is called as a father of computer?
a) William Oughtred
b) John Von Numan
c) Charless Babbage
d) Herman Hollerith
Answer:
c) Charless Babbage

Question 2.
The Analytical Engine was invented in the year _______.
a) 1837
b) 1937
c) 1847
d) 1873
Answer:
a) 1837

Question 3.
The Analytical Engine contained _______.
a) ALU
b) Basic flow control
c) Integrated memory
d) All the above
Answer:
d) All the above

Question 4.
Which led to the development of general purpose computers?
a) Napier’s Bone
b) Analytical Engine
c) Slide Rule
d) None of these
Answer:
b) Analytical Engine

Question 5.
Which computing method was slow and prone to errors?
a) computerized
b) manual
c) both A and B
d) Neither A nor B
Answer:
b) manual

Question 6.
_______ is the first known calculating device.
a) Napier’s Bone
b) Slide Rule
c) Punched Card
d) Abacus
Answer:
d) Abacus

Question 7.
The Abacus was used for _______ operation,
a) Addition
b) Multiplication
c) Division
d) All the above
Answer:
a) Addition

Question 8.
Based on various stages of development, computers can be categorized in to ________ generations.
a) 3
b) 4
c) 5
d) 6
Answer:
d) 6

Question 9.
The period of first generation is ________.
a) 1942 – 1955
b) 1955 – 1964
c) 1964- 1975
d) 1975-1980
Answer:
a) 1942 – 1955

Question 10.
The period of second generation is ________.
a) 1942- 1955
b) 1955- 1964
c) 1964 – 1975
d) 1975-1980
Answer:
b) 1955- 1964

Samacheer Kalvi 11th Computer Applications Guide Chapter 1 Introduction to Computers

Question 11.
The period of third generation is ________.
a) 1942- 1955
b) 1955- 1964
c) 1964 – 1975
d) 1975 – 1980
Answer:
c) 1964 – 1975

Question 12.
The period of fourth generation is _______.
a) 1942- 1955
b) 1955- 1964
c) 1964- 1975
d) 1975- 1980
Answer:
d) 1975- 1980

Question 13.
The period of fifth generation is _______.
a) 1980 – till date
b) 1955 – 1964
c) 1964 – 1975
d) 1975-1980
Answer:
a) 1980 – till date

Question 14.
The period of sixth generation is _______.
a) 1980 – till date
b) 1975 – 1980
c) 1964 – 1975
d) In future
Answer:
d) In future

Question 15.
_______ is a first generation computer.
a) ENIAC
b) EDVAC
c) UNIVAC
d) All the above
Answer:
d) All the above

Question 16.
_______ is a second generation computer.
a) IBM 1401
b) IBM 1620
c) UNIVAC 1108
d) All the above
Answer:
d) All the above

Question 17.
_______ is a third generation computer.
a) IBM 360 series
b) Honey well 6000 series
c) IBM 1620
d) Both A and B
Answer:
d) Both A and B

Question 18.
The weight of ENIAC was _______ tons.
a) 27
b) 37
c) 28
d) 17
Answer:
a) 27

Question 19.
The size of ENIAC was _______.
a) 8 feet x 100 feet x 3 feet
b) 3 feet x 100 feet x 8 feet
c) 100 feet x 8 feet x 3 feet
d) 8 feet x 3 feet x 100 feet
Answer:
a) 8 feet x 100 feet x 3 feet

Question 20.
The ENIAC conusmed _______ watts of power.
a) 150
b) 100
c) 1500
d) 15
Answer:
a) 150

Question 21.
The main component used in first generation computer is _______.
a) Transistors
b) Integrated Circuits
c) Vacuum Tube
d) Micro processor
Answer:
c) Vacuum Tube

Samacheer Kalvi 11th Computer Applications Guide Chapter 1 Introduction to Computers

Question 22.
The main component used in second generation computer is _______.
a) Transistors
b) Integrated Circuits
c) Vacuum Tube
d) Micro processor
Answer:
a) Transistors

Question 23.
The main component used in third generation computer is _______.
a) Transistors
b) Integrated Circuits
c) Vacuum Tube
d) Micro processor
Answer:
b) Integrated Circuits

Question 24.
The main component used in fourth generation computer is _______.
a) Transistors
b) Integrated Circuits
c) Vacuum Tube
d) Microprocessor
Answer:
d) Microprocessor

Question 25.
The main component used in fifth generation computer is _______.
a) Transistors
b) Integrated Circuits
c) Ultra Large Scale Integration
d) Micro processor
Answer:
c) Ultra Large Scale Integration

Question 26.
The first operating system was developed during _______ generation of computers.
a) first
b) second
c) third
d) fourth
Answer:
b) second

Question 27.
Batch processing and Multiprogramming was developed during _______ generation of computers.
a) first
b) second
c) third
d) fourth
Answer:
b) second

Question 28.
_______ language was used in first generation computer.
a) Machine
b) Assembly
c) High Level
d) English
Answer:
a) Machine

Question 29.
_______ language was used in second generation computer.
a) Machine
b) Assembly
c) High Level
d) Both A and B
Answer:
d) Both A and B

Question 30.
_______ language was used in third generation computer.
a) Machine
b) Assembly
c) High Level
d) English
Answer:
c) High Level

Samacheer Kalvi 11th Computer Applications Guide Chapter 1 Introduction to Computers

Question 31.
Micro computer series such as IBM and APPLE were developed during _______ generation.
a) Sixth
b) Fifth
c) Fourth
d) None of these
Answer:
c) Fourth

Question 32.
Portable computers were introduced in ______ generation.
a) Third
b) Fifth
c) Fourth
d) None of these
Answer:
c) Fourth

Question 33.
_______ generation computer can recognize Images and Graphics.
a) Sixth
b) Fifth
c) Fourth
d) Second
Answer:
b) Fifth

Question 34.
Artificial Inegelligence introduced in _______ generation.
a) Third
b) Fifth
c) Fourth
d) Second
Answer:
b) Fifth

Question 35.
Expert Syetem introduced in _________ generation.
a) Third
b) Fifth
c) Fourth
d) Second
Answer:
b) Fifth

Question 36.
_______ generation computers are capable of solving complex problems including decision making and logical reasoning.
a) Third
b) Fifth
c) Fourth
d) Second
Answer:
b) Fifth

Question 37.
Parallel processing introduced in _______ generation.
a) Third
b) Fifth
c) Fourth
d) Second
Answer:
b) Fifth

Question 38.
The ENIAC was invented by _______.
a) J.Presper
b) John Mauchly
c) Both A and B
d) Charless Babbage
Answer:
c) Both A and B

Samacheer Kalvi 11th Computer Applications Guide Chapter 1 Introduction to Computers

Question 39.
The ENIAC was developed at _______.
a) University of Pennsylvania
b) Oxford University
c) Microsoft
d) None of these
Answer:
a) University of Pennsylvania

Question 40.
The ENIAC was developed in the year _______.
a) 1947
b) 1943
c) 1942
d) 1843
Answer:
b) 1943

Question 41.
The ENIAC used _______ number of vacuum tubes,
a) 19000
b) 18000
c) 28000
d) 18900
Answer:
b) 18000

Question 42.
_______ is a component of Artificial Intelligence.
a) Natural Language Processing
b) Parallel Processing
c) both A and B
d) None of these
Answer:
a) Natural Language Processing

Question 43.
_______ provides the ability to develop the computer program to understand human language.
a) Natural Language Processing
b) Parallel Processing
c) both A and B
d) None of these
Answer:
a) Natural Language Processing

Question 44.
The term “computer” is derived from the word _______.
a) compute
b) calculate
c) process
d) None of these
Answer:
a) compute

Question 45.
The term “compute” means _______.
a) computer
b) calculate
c) process
d) None of these
Answer:
b) calculate

Question 46.
Before 19th century, the person who performs calculation is called as _______.
a) Computer
b) Calculator
c) Abacus
d) None of these
Answer:
a) Computer

Question 47.
_______ is defined as an unprocessed collection of raw facts.
a) information
b) datum
c) data
d) None of these
Answer:
c) data

Question 48.
_______ will not give meaning.
a) information
b) datum
c) data
d) None of these
Answer:
c) data

Question 49.
_______ is a collection of facts from which conclusions may be drawn.
a) information
b) datum
c) data
d) None of these
Answer:
a) information

Samacheer Kalvi 11th Computer Applications Guide Chapter 1 Introduction to Computers

Question 50.
_______ is a processed fact.
a) information
b) datum
c) data
d) None of these
Answer:
a) information

Question 51.
A set of instructions are called _______.
a) pseudo code
b) program
c) walk through
d) all the above
Answer:
b) program

Question 52.
The _______ is the combination of hardware and software.
a) computer
b) analytical engine
c) calculator
d) all the above
Answer:
a) computer

Question 53.
_______ is the physical component of a computer.
a) software
b) hardware
c) freeware
d) Malware
Answer:
b) hardware

Question 54.
_______ is the set of programs or instructions.
a) software
b) hardware
c) freeware
d) Malware
Answer:
a) software

Question 55.
IPO menas _______.
a) Input-Process-Output
b) Intelligence Process Output
c) Integral Program Output
d) Internet Process Outcome
Answer:
a) Input-Process-Output

Question 56.
Every task given to the computer follows _______ cycle.
a) Input-Process-Output
b) Output-Process-Input
c) Process-Output-Input
d) Input-Output-Process
Answer:
a) Input-Process-Output

Question 57.
_______ unit is used to feed any form of data to the computer.
a Process
b) Arithmetic and Logic
c) Input
d) None of these
Answer:
c) Input

Question 58.
_______ of a computer interprets and executes software instructions.
a) Input unit
b) Main Memory
c) Central Process Unit
d) Secondary Memory
Answer:
c) Central Process Unit

Question 59.
_______ control the components such as memory, input and output units.
a) Input unit
b) Main Memory
c) Central Process Unit
d) Secondary Memory
Answer:
c) Central Process Unit

Question 60.
The CPU has _______ components.
a) 4
b) 3
c) 5
d) 2
Answer:
b) 3

Question 61.
_______ is a component of CPU.
a) Control unit
b) ALU
c) Memory unit
d) All the above
Answer:
d) All the above

Samacheer Kalvi 11th Computer Applications Guide Chapter 1 Introduction to Computers

Question 62.
In _______ unit, various computing functions are performed on data.
a) Control unit
b) ALU
c) Memory unit
d) All the above
Answer:
b) ALU

Question 63.
The result of an operation is stored in _______ of CPU.
a) Secondary storage
b) Main memory
c) Internal memory
d) None of these
Answer:
c) Internal memory

Question 64.
The _______ operations of ALU promote the decision-making ability of a computer,
a) arithmetic
b) logical
c) relational
d) increment/decrement
Answer:
b) logical

Question 65.
_______ controls the entire operation of a computer.
a) Control unit
b) ALU
c) Memory unit
d) All the above
Answer:
a) Control unit

Question 66.
The _______ unit controls the flow of data between the CPU, memory and I/O devices.
a) Control unit
b) ALU
c) Memory unit
d) All the above
Answer:
a) Control unit

Question 67.
_______ unit is any hardware component that conveys information to user in an understandable form.
a) Input unit
b) Output unit
c) Memory unit
d) All the above types.
Answer:
b) Output unit

Question 68.
The memory is of _______ types.
a) 2
b) 3
c) 4
d) 5
Answer:
a) 2

Question 69.
The _______ memory is used to temporarily store the programs and data when the instructions are ready to execute.
a) Primary memory
b) Output unit
c) Secondary memory
d) All the above
Answer:
a) Primary memory

Question 70.
The _______ memory is used to store the data permanently.
a) Primary memory
b) Output unit
c) Secondary memory
d) All the above
Answer:
c) Secondary memory

Question 71.
The _______ memory is volatile.
a) Primary memory
b) Output unit
c) Secondary memory
d) All the above
Answer:
a) Primary memory

Question 72.
In _______ memory, the content is lost when the power supply is switched off.
a) Primary memory
b) RAM
c) Secondary memory
d) Either A or B
Answer:
d) Either A or B

Question 73.
_______ is an example of a main memory.
a) ROM
b) PROM
c) RAM
d) EPROM
Answer:
c) RAM

Question 74.
The _______ memory is non-volatile.
a) Primary memory
b) Output unit
c) Secondary memory
d) All the above
Answer:
c) Secondary memory

Question 75.
_______ memory, the content is available even after the power supply is switched off.
a) Primary memory
b) RAM
c) Secondary memory
d) Either A or B
Answer:
c) Secondary memory

Question 76.
_______ is an example of a secondary memory.
a) CD-ROM
b) DVD-ROM
c) Hard disk
d) All the above
Answer:
d) All the above

Question 77.
_______ is the most common input device.
a) scanner
b) keyboard
c) bar code reader
d) none of these
Answer:
b) keyboard

Question 78.
The keyboard layout is derived from the keyboard of original _______.
a) typewriter
b) key punching machine
c) touch screen
d) None of these
Answer:
a) typewriter

Question 79.
_______ is a pointing device.
a) scanner
b) keyboard
c) mouse
d) none of these
Answer:
c) mouse

Samacheer Kalvi 11th Computer Applications Guide Chapter 1 Introduction to Computers

Question 80.
________ device is used to control the movement of the cursor on the display screen.
a) scanner
b) keyboard
c) mouse
d) none of these
Answer:
c) mouse

Question 81.
_______ device is used to select icons, menus, command buttons or activate something on a computer.
a) scanner
b) keyboard
c) mouse
d) none of these
Answer:
c) mouse

Question 82.
_______ is a mouse action.
a) drag and drop
b) right dick
c) move
d) all the above
Answer:
d) all the above

Question 83.
_______ is a mouse type.
a) Mechanical
b) Optical
c) Laser
d) All the above
Answer:
c) Laser

Question 84.
The mechanical mouse was developed and introduced by _______.
a) Telefunken
b) Microsoft
c) Intel
d) None of these
Answer:
a) Telefunken

Question 85.
The mechanical mouse was developed and introduced in the year _______.
a) 1968
b) 1966
c) 1978
d) 1969
Answer:
a) 1968

Question 86.
The optical mouse introduced by _____was developed and introduced by _______.
a) Telefunken
b) Steve Krish
c) Richard Lyon
d) Both B and C
Answer:
d) Both B and C

Question 87.
The optical mouse was developed introduced in the year ________.
a) 1968
b) 1966
c) 1978
d) 1988
Answer:
d) 1988

Question 88.
The optical mouse has _______ Buttons.
a) 4
b) 5
c) 3
d) no
Answer:
c) 3

Question 89.
_______ mouse is highly sensitive andabie to work on any hard surface.
a) optical
b) mechanical
c) laser
d) all the above
Answer:
c) laser

Question 90.
Who invented Mouse?
a) Telefunken
b) steve
c) Richard Lyon
d) Douglas Engelbart
Answer:
d) Douglas Engelbart

Question 91.
Who assist Douglas Engel bard to invent moused?
a) Bill English
b) Steve Krish
c) Richard Lyon
d) None of these
Answer:
a) Bill English

Question 92.
_______ is used to ener the information directly into the computer’s memory.
a) Mouse
b) Scanner
c) Light Pen
d) All the above
Answer:
b) Scanner

Question 93.
The ________ device works like a Xerox machine.
a) Mouse
b) Scanner
c) Light Pen
d) AU the above
Answer:
b) Scanner

Question 94.
The ________ device is used for computer security.
a) Fingerprint Scanner
b) Scanner
c) Light Pen
d) All the above
Answer:
a) Fingerprint Scanner

Question 95.
_______ device uses biometric technology.
a) Fingerprint Scanner
b) Track ball
c) Light Pen
d) All the above
Answer:
a) Fingerprint Scanner

Question 96.
________ scanner uses unique patterns of a person’s retiant blood vessels.
a) Retinal
b) Track ball
c) Light Pen
d) All the above
Answer:
a) Retinal

Question 97.
________ is used to draw directly onto the screen.
a) Mouse
b) Light Pen
c) OCR
d) MICR
Answer:
b) Light Pen

Question 98.
________ is a pointing device.
a) Mouse
b) Light Pen
c) OCR
d) Both A and B
Answer:
d) Both A and B

Question 99.
________ is a device which detects characters printed or written on a paper.
a) Retinal scanner
b) Light Pen
c) OCR
d) Both A and B
Answer:
c) OCR

Question 100.
The document scanned through _______ device can be edited using a word processor.
a) Retinal scanner
b) Light Pen
c) OCR
d) Both A and B
Answer:
c) OCR

Question 101.
A user can scan a page from a book using ________ and can be edited using a word processor.
a) Retinal scanner
c) OCR
c) OCR
b) Light Pen
Answer:
c) OCR

Question 102.
The ________ is two dimension bar code which can be read by a camera and processed to interpret the image.
a) Retinal scanner
b) Light Pen
c) OCR
d) QR code
Answer:
d) QR code

Samacheer Kalvi 11th Computer Applications Guide Chapter 1 Introduction to Computers

Question 103.
The ___________ system gives fast and error free entry of information into the computer.
a) Bar Code
b) Light Pen
c) OCR
d) QR code
Answer:
a) Bar Code

Question 104.
_______ serves as a voice input device.
a) Bar Code Reader
b) Microphone
c) OCR
d) QR code reader
Answer:
b) Microphone

Question 105.
_______ captures images / videos directly in the digital form.
a) Bar Code Reader
b) Microphone
c) Digital Camera
d) QR code reader
Answer:
c) Digital Camera

Question 106.
_______ uses a CCD electronic chip.
a) Bar Code Reader
b) Microphone
c) Digital Camera
d) QR code reader
Answer:
c) Digital Camera

Question 107.
CCD means _______.
a) Charge Coupled Device
b) Change Coupled Device
c) Close Circuit Device
d) Charge Coupled Data
Answer:
a) Charge Coupled Device

Question 108.
________ converts fight rays into digital formats.
a) Bar Code Reader
b) Microphone
c) Digital Camera
d) QR code reader
Answer:
c) Digital Camera

Question 109.
A _______ is a display device that allows the user to interact with a computer by using the finger.
a) Touch Screen
b) Microphone
c) Digital Camera
d) QR code reader
Answer:
a) Touch Screen

Question 110.
_______ is an alternative to a mouse or keyboard for navigating a Graphical User Interface.
a) Touch Screen
b) Microphone
c) Digital Camera
d) QR code reader
Answer:
a) Touch Screen

Question 111.
Touch screen is used on _______.
a) Smart phone
b) Information kiosks
c) Cash registers
d) All the above
Answer:
d) All the above

Question 112.
_______ is a device for signaling by hand, by way of pressing one or more switches.
a) Touch Screen
b) Keyer
c) Digital Camera
d) QR code reader
Answer:
b) Keyer

Question 113.
________ number of keys available in Keyer.
a) 4 to 50
b) 4 to 500
c) Question 14
d) 50
Answer:
a) 4 to 50

Question 114.
In _______ device, the keys are arranged in a cluster.
a) Touch Screen
b) Keyer
c) Digital Camera
d) QR code reader
Answer:
b) Keyer

Question 115.
_______ is the most commonly used output device to display the information.
a) Plotter
b) Monitor
c) Speaker
d) All the above
Answer:
b) Monitor

Question 116.
Pictures on a monitor are formed with picture elements called _______.
a) Pixels
b) Points
c) Dots
d) None of these
Answer:
a) Pixels

Question 117.
________ is a monitor type.
a) CRT
b) LED
c) LCD
d) All the above
Answer:
d) All the above

Question 118.
CRT stands for _______.
a) Cathode Ray Tube
b) Carbon Ray Tube
c) Cathode Ray Terminal
d) Cathode Ray Tunnel
Answer:
a) Cathode Ray Tube

Question 119.
LED stands for _______.
a) Light Emitting Diodes
b) Light Emitting Device
c) Liquid Emitting Diodes
d) Light. Extracting Device
Answer:
a) Light Emitting Diodes

Question 120.
LCD stands for _______.
a) Liquid Crystal Display
b) Light Crystal Display
c) Large Crystal Display
d) Liquid Circuit Display
Answer:
a) Liquid Crystal Display

Question 121.
The monitor works with _______.
a) CGA
b) VGA
c) MGA
d) None of these
Answer:
b) VGA

Samacheer Kalvi 11th Computer Applications Guide Chapter 1 Introduction to Computers

Question 122.
VGA stands for _______.
a) Video Graphics Array
b) Video Generation Array
c) Video Graphics Adapter
d) Vector Generation Array
Answer:
a) Video Graphics Array

Question 123.
_______ acts as an interface between the computer and display monitor.
a) CGA
b) VGA
c) MGA
d) None of these
Answer:
b) VGA

Question 124.
The first computer monitor was released on _______.
a) March 1, 1973
b) March 31, 1973
c) March 21, 1973
d) March 1, 1963
Answer:
a) March 1, 1973

Question 125.
The first computer monitor was part of the _______ computer system.
a) Alto Xerox
b) Xerox Alto
c) Xerox
d) Alto
Answer:
b) Xerox Alto

Question 126.
The communicate with the screen.
a) Video Graphics Card
b) Video Graphics Channel
c) Video Group Card
d) Video Generation Card
Answer:
a) Video Graphics Card

Question 127.
_______ is an output device that is used to produce graphical output on papers.
a) Monitor
b) Plotter
c) Speaker
d) None of these
Answer:
b) Plotter

Question 128.
Printers are divided into _______ categories.
a) 2
b) 3
c) 4
d) 5
Answer:
a) 2

Question 129.
_______ printers print with striking of hammers or pins on ribbon.
a) Non-impact
b) Impact
c) plotter
d) None of these
Answer:
b) Impact

Question 130.
_______ printer is an impact printer.
a) Dot matrix
b) Line
c) Laser
d) Both A and B
Answer:
c) Laser

Question 131.
A _______ printer prints using a fixed number of pins or wires.
a) Dot matrix
b) Line
c) Laser
d) Both A and B
Answer:
a) Dot matrix

Question 132.
The priting speed of a Dot matrix printer is _______ CPS.
a) 300 to 1550
b) 30 to 1550
c) 30 to 1555
d) 30 to 1505
Answer:
b) 30 to 1550

Question 133.
_______ printer uses a fixed print head for priting.
a) Dot matrix
b) More than 1000
c) Laser
d) less than 500
Answer:
b) More than 1000

Question 134.
The priting speed of a line printer _________ LPM.
a) Less than 1000
b) More than 1000
c) 300
d) less than 500
Answer:
b) More than 1000

Question 135.
CPS stands for _______.
a) Character Printing Speed
b) Character Per Second
c) Character Per Stroke
d) Character Per Session
Answer:
b) Character Per Second

Question 136.
________ printers do not use striking mechanism for printing.
a) Non-impact
b) Impact
c) Both A and B
d) None of these
Answer:
a) Non-impact

Question 137.
_______ printer is a Non-impact printer,
a) Laser
b) Inkjet
c) Line
d) Both A and B
Answer:
d) Both A and B

Question 138.
The chief characteristics of laser printer is their ________.
a) printing speed
b) resolution
c) cost
d) All the above
Answer:
b) resolution

Samacheer Kalvi 11th Computer Applications Guide Chapter 1 Introduction to Computers

Question 139.
The resolution of a laser printer is measured in the unit _______.
b) LPM
d) None of these
b) Dots Per Instance
d) None of these
Answer:

Question 140.
DPI stands for _______.
a) Dots Per Inch
b) Dots per Insurance
c) Darkness Per Inch
d) None of these
Answer:
a) Dots Per Inch

Question 141.
The available resolution range of a laser printer around _______ DPI.
a) 1024
b) 12000
c) 1200
d) 1020
Answer:
c) 1200

Question 142.
The priting speed of a Laser printer is approximately _______ PPM.
a) 100
b) 1000
c) 1200
d) 1024
Answer:
a) 100

Question 143.
Inkjet printer uses ________ colour inks to create colour tones.
a) Magenta
b) Yellow
c) Cyan
d) All the above
Answer:
d) All the above

Question 144.
PPM stands for _______.
a) Paper Per Minute
b) Paper Per Moment
c) Pixels Per Minute
d) None of these
Answer:
a) Paper Per Minute

Question 145.
_______ produces voice output.
a) Plotter
b) Speaker
c) Mic
d) None of these
Answer:
b) Speaker

Question 146.
_______ is used to produce computer output on a big screen.
a) Speaker
b) Plotter
c) Multimedia projector
d) All the above
Answer:
c) Multimedia projector

Question 147.
A(n) _______ is a basic software that makes the computer to work.
a) Application software
b) Compiler
c) Loader
d) Operating system
Answer:
d) Operating system

Question 148.
POST sequence check the device .
a) RAM
b) Keyboard
c) Monitor
d) All the above
Answer:
d) All the above

Question 149.
If POST sequence is successful then _______ gets executed.
a) BIOS
b) Application program
c) Compiler
d) None of these
Answer:
a) BIOS

Question 150.
BIOS means _______.
a) Basic Input Output System
b) Basic Input Output Scheme
c) Best Input Output System
d) Beginners Input Output System
Answer:
a) Basic Input Output System

Question 151.
After POST sequence, BIOS gets execute is called _______.
a) booting
b) shutdown
c) hibernate
d) login
Answer:
a) booting

Question 152.
Booting process is of _______ types.
a) 5
b) 4
c) 3
d) 2
Answer:
d) 2

Samacheer Kalvi 11th Computer Applications Guide Chapter 1 Introduction to Computers

Question 153.
When the system starts from initial state when the computer is switched on is called ______ booting.
a) Warm
b) Cold
c) Hard
d) Either B or C
Answer:
b) Cold

Question 154.
When the user presses the Power button, the instructions are read from the ______ to initiate the booting process.
a) RAM
b) CD-RAM
c) Hard disk
d) ROM
Answer:
d) ROM

Question 155.
When the system restarts or when Reset button is pressed _______ booting
a) Warm
b) Soft
c) Hard
d) Either A or B
Answer:
d) Either A or B

Question 156.
During _______ booting, there are chances of data loss and system damage as the data might not have been stored properly.
a) Warm
b) Soft
c) Hard
d) Either A or B
Answer:
d) Either A or B

Question 157.
_______ interprets and executes software instructions.
a) ALU
b) CPU
c) Cache memory
d) None of these
Answer:
b) CPU

Question 158.
There are totally ______ Symbols / Graphemes / Characters in the Indus Script.
a) 417
b) 407
c) 471
d) 147
Answer:
a) 417

Question 159.
_______ is a sub-field of Artificial Intelligence.
a) Neural Network
b) Nature Network
c) GUI
d) None of these
Answer:
a) Neural Network

Question 160.
Expand USB _______.
a) Universal Serial Bus
b) Unique Serial Bus
c) Universal Serial Board
d) Universal Serial Booting
Answer:
a) Universal Serial Bus

Question 161.
Transistor means _______.
a) Transfer resistance
b) Transfer register
c) Track resistance
d) Tangent resistance
Answer:
a) Transfer resistance

Question 162.
LPM stands for ______.
a) Lines Per Minute
b) Lines Per Moment
c) Line Print Machine
d) Line Print Mechanism
Answer:
a) Lines Per Minute

Part – II

Short Answers

Question 1.
Why Charles Babbage is called as father of modern computer.
Answer:
Charles Babbage is considered to be the father of computer, for his invention and the concept of Analytical Engine in 1837. The Analytical Engine contained an Arithmetic Logic Unit (ALU), basic flow control, and integrated memory; which led to the development of first general purpose computer concept.

Question 2.
Write note on ENIAC.
Answer:
The ENIAC (Electronic Numerical Integrator And Calculator) was invented by 1 Presper Eckert and John Mauchly at the University of Pennsylvania and began construction in 1943 and was not completed until 1946. It occupied about 1,800 square feet and used about 18,000 vacuum tubes, weighing almost 50 tons. ENIAC was the first digital computer because it was fully functional.

Question 3.
Write note on Optical Character Recognition Engine.
Answer:
Optical Character Recognition (Optical Grapheme Recognition) engine for the Indus Scripts has been developed using Deep Learning Neural Networks. Given photographs, scans, or any image feed of an Indus Valley Civilization ‘ artifact, the system will be able to recognize the inscriptions (the symbol / grapheme sequences) from the image. There are totally 417 Symbols/ Graphemes/ Characters in the Indus Scripts and just 3700+ text inscriptions of data for the machine to learn and attain expert-level status.

Question 4.
Define Data.
Answer:
Data is defined as an un-processed collection of raw facts, suitable for communication, interpretation or processing.

Question 5.
Define Information.
Answer:
Information is a processed fact from which conclusions may be drawn.

Samacheer Kalvi 11th Computer Applications Guide Chapter 1 Introduction to Computers

Question 6.
Define Hardware.
Answer:
Hardware is the physical component of a computer like motherboard, memory devices, monitor, keyboard etc.

Question 7.
Define Software.
Answer:
Software is the set of programs or instructions. It is classified into System software (Ex. Operating system) and Application software (Ex. MS-Word).

Question 8.
Write note on IPO cycle.
Answer:
Every task given to a computer follows an Input- Process- Output Cycle (IPO cycle). It needs certain input, processes that input and produces the desired output. The input unit takes the input, the central processing unit does the processing of data and the output unit produces the output.

Question 9.
Write note on Input unit.
Answer:
Input unit is used to feed any form of data to the computer, which can be stored in the memory unit for further processing.

Example:
Keyboard, mouse, etc.

Question 10.
Write note on output unit.
Answer:
An Output Unit is any hardware component that conveys information to users in an understandable form. Example: Monitor, Printer etc.

Question 11.
Write note on primary memory.
Answer:
The primary memory is volatile, that is, the content is lost when the power supply is switched off. Ex. Random Access Memory (RAM),

Question 12.
Write note on secondary memory.
Answer:
The secondary memory is non-volatile, that is, the content is available even after the power supply is switched off.

Example: Hard disk, CD-ROM , DVD ROM etc.

Samacheer Kalvi 11th Computer Applications Guide Chapter 1 Introduction to Computers

Question 13.
Who invented Mouse?
Answer:
The computer mouse was invented and developed by Douglas Engelbart, with the assistance of Bill English, during the 1960’s and was patented on November 17, 1970.

Question 14.
What is use of scanner?
Answer:
Scanners are used to enter the information directly into the computer’s memory. This device works like a Xerox machine. The scanner converts any type of printed or written Information including photographs into a digital format, which can be manipulated by the computer.

Question 15.
What are the types of keyboard?
Answer:
The keyboard types are :

  1. Wired keyboard.
  2. Wireless keyboard.
  3. Virtual keyboard.

Question 16.
Write short note on Track ball.
Answer:
Track bail is similar to the upside down design of the mouse. The user moves the ball directly, while the device itself remains stationary. The user spins the bail in various directions to navigate the screen movements.

Question 17.
What is the use of Retinal scanner?
Answer:
This performs a retinal scan which is a biometric technique that uses unique patterns on a person s retinal blood vessels.

Question 18.
Write short note on Barcode reader.
Answer:
A Bar code is a pattern printed in lines of different thickness. The Bar code reader scans the information on the bar codes transmits to the Computer for further processing. The system gives fast and error free entry of information into the computer.

Question 19.
Write short note on QR code reader.
Answer:
The QR (Quick response) code is the two dimension bar code which can be read by a camera and processed to interpret the image.

Question 20.
What is the use of Voice Input System?
Answer:
Microphone serves as a voice Input device. It captures the voice data and send it to the computer. Using the microphone along with speech recognition software can offer a completely new approach to input information into the Computer,

Question 21.
Write short note oh Digital Camera.
Answer:
It captures images / videos directly in the digital form. It uses a CCD (Charge Coupled Device) electronic chip. When light falls on the chip through the lens, it converts light rays into digital format.

Question 22.
Write about Plotter.
Answer:
Plotter is an output device that is used to produce graphical output on papers. It uses single color or multi color pens to draw pictures,

Question 23.
Write short note on printer.
Answer:
Printers are used to print the information on papers. Printers are divided into two main categories:

  1. Impact Printers
  2. Non Impact printers.

Question 24.
Write about Multimedia Projectors.
Answer:
Multimedia projectors are used to produce computer output on a big screen. These are used to display presentations in meeting halls or in classrooms.

Question 25.
What do you mean by natural language processing?
Answer:
It is a method used in artificial intelligence to process and derive meaning from the human language.

Samacheer Kalvi 11th Computer Applications Guide Chapter 1 Introduction to Computers

Question 28.
Write about Robotics.
Answer:
Robot is a term coined by Karel Capek in 1921 to play RUR (Rossum’s Universal Robots). It is used to describe a computerized machine designed to respond to input received manually or from its surroundings.

Question 27.
Write note on Nanotechnology.
Answer:
Nanotechnology is an engineering, science and technology that develops machines or works with one atom or one molecule that is 100 nanometers or smaller.

Question 28.
Write note on Bioengineering.
Answer:
It is a discipline that applies engineering principles of design and analysis to biological systems and biomedical technologies.

Question 29.
What is high level language?
Answer:
A high level language is a computer programming language that is not limited by the computer, designed for a specific job and is easier to understand.

Question 30.
Write, about Integrated Circuits.
Answer:
The integrated circuit is a package containing many circuits, pathways, transistors and other electronic components all working together to perform a particular function or a series of functions.

Question 31.
Write note on punched card.
Answer:
It also known as Hollerith card is paper card containing several punched or perforated holes that were punched by hand or machine to represent data.

Part – III

Explain In Brief

Question 1.
Write note on keyboard.
Answer:
Keyboard is the most common input device used today. The individual keys for letters, numbers and special characters are collectively known as character keys. This keyboard layout is derived from the keyboard of original typewriter.

The data and instructions are given as input to the computer by typing on the keyboard) Apart from alphabet and numeric keys, it also has Function keys for performing different functions. There are different set of keys available in the keyboard such as character keys, modifier keys, system and GUI keys, enter and editing keys, function keys, navigation keys, numeric keypad and lock keys.

Question 2.
What is the purpose of Fingerprint scanner?
Answer:
Finger print Scanner is a fingerprint recognition device used for computer security, equipped with the fingerprint recognition feature that uses biometric technology. Fingerprint Reader / Scanner is a very safe and convenient device for security instead of using passwords, which is vulnerable to fraud and is hard to remember.

Question 3.
Write note on Light Pen.
Answer:
A light pen is a pointing device shaped like a pen and is connected to a monitor. The tip of the light pen contains a light-sensitive element which detects the light from the screen enabling the computer to identify the location of the pen on the screen. Light pens have the advantage of ‘drawing’ directly onto the screen, but this becomes hard to use, and is also not accurate.

Question 4.
What is the purpose of Optical Character Reader.
Answer:
It is a device which detects characters printed or written on a paper with OCR, a user can scan a page from a book. The Computer will recognize the characters in the page as letters and punctuation marks and stores. The Scanned document can be edited using a wordprocessor.

Question 5.
Write note on Touch screen.
Answer:
A touch screen is a display device that allows the user to interact with a computer by using the finger. It can be quite useful as an alternative to a mouse or keyboard for navigating a Graphical User Interface (GUI).

Touch screens are used on a wide variety of devices such as computers, laptops, monitors, smart phones, tablets, cash registers and information kiosks. Some touch screens use a grid of infrared beams to sense the presence of a finger instead of utilizing touch-sensitive input.

Question 6.
Write about Keyer.
Answer:
A Keyer is a device for signaling by hand, by way of pressing one or more switches. Modern keyers have a large number of switches but not as many as a full size keyboard. Typically, this number is between 4 and 50. A keyer differs from a keyboard, which has “no board”, but the keys are arranged in a cluster.

Samacheer Kalvi 11th Computer Applications Guide Chapter 1 Introduction to Computers

Question 7.
Explain briefly about Monitor.
Answer:
Monitor is the most commonly used output device to display the information. Pictures on a monitor are formed with picture elements called PIXELS. Monitors may either be Monochrome or can be color. There are many types of monitors available such as CRT (Cathode Ray Tube), LCD (Liquid Crystal Display) and LED (Light Emitting Diodes).

The monitor works with the VGA (Video Graphics Array) card) The video graphics card helps the keyboard to communicate with the screen. It acts as an interface between the computer and display monitor. The first computer monitor was part of the Xerox Alto computer system, which was released on March 1, 1973.

Question 8.
Write about speaker? Where it is mostly used?
Answer:
Speakers produce voice output (audio). Using speaker along with speech synthesize software, the computer can provide voice output. This has become very common in places like airlines, schools, banks, railway stations, etc.

Question 9.
Compare assembly language and machine language.
Answer:
An assembly language is a low level programming language. Machine language is a collection of binary digits or bits that the computer reads and interprets directly.

Question 10.
Write note on i) Transistor ii) Vacuum tube
Answer:
i) Transistor : The transistor (transfer resistance) is made up of semi conductors. It is a component used to control the amount of current or voltage used for amplification / modulation of an electronic signal.

ii) Vacuum Tube : It contains electrodes for controlling electron flow and were used in early computers as a switch or an amplifier.

Part – IV

Explain In Detail

Question 1.
Explain the types of Mouse.
Answer:
Different types of mouse available are: Mechanical Mouse, Optical, Laser Mouse, Air Mouse, 3D Mouse, Tactile Mouse, Ergonomic Mouse and Gaming Mouse.
Samacheer Kalvi 11th Computer Applications Guide Chapter 1 Introduction to Computers 3

Question 2.
Explain briefly about impact printers.
Answer:
These printers print with striking of hammers or pins on ribbon. These printers can print on multi¬part (using carbon papers) by using mechanical pressure. Ex: Dot Matrix printers and Line matrix printers.

A Dot matrix printer that prints using a fixed number of pins or wires. Each dot is produced by a tiny metal rod, also called a “wire” or “pin” which works by the power of a tiny electromagnet or solenoid, either directly or through a set of small levers. It generally prints one line of text at a time. The printing speed of these printers varies from 30 to 1550 CPS (Character Per Second).

Line matrix printers use a fixed print head for printing. Basically, it prints a page-wide line of dots. But it builds up a line of text by printing lines of dots. Line printers are capable of printing much more than 1000 Lines Per Minute, resulting in thousands of pages per hour. These printers are also uses mechanical pressure to print on multi-part (using carbon papers).

Samacheer Kalvi 11th Computer Applications Guide Chapter 1 Introduction to Computers

Question 3.
Explain briefly about non-impact printers.
Answer:
These printers do not use striking mechanism for printing. They use electrostatic or laser technology. Quality and speed of these printers are better than Impact printers. Ex: Laser printers and Inkjet printers.

Laser Printers :
Laser printers mostly work with similar technology used by photocopiers. It makes a laser beam scan back and forth across a drum inside the printer, building up a pattern. It can produce very good quality of graphic images. One of the chief characteristics of laser printer is their resolution – how many Dots per inch (DPI). The available resolution range around 1200 dpi. Approximately it can print 100 pages per minute (PPM).

Inkjet Printers:
Inkjet Printers use colour cartridges which combined Magenta, Yellow and Cyan inks to create color tones. A black cartridge is also used for monochrome output. Inkjet printers work by spraying ionised ink at a sheet of paper. The speed of Inkjet printers generaly range from 1-20 PPM (Page Per Minute).

They use the technology of firing ink by heating it so that it explodes towards the paper in bubbles or by using piezoelectricity in which tiny electric currents controlled by electronic circuits are used inside the printer to spread ink in jet speed) An Inkjet printer can spread millions of dots of ink at the paper every single second.

Question 4.
Explain briefly about booting of computer. Explain its types.
Answer:
An Operating system (OS) is a basic software that makes the computer to work. When. a computer is switched on, there is no information in its RAM. At the same time, in ROM, the pre-written program called POST (Power on Self Test) will be executed first. This program checks if the devices like RAM, keyboard, etc), are connected properly and ready to operate.

If these devices are ready, then the BIOS (Basic Input Output System) gets executed) This process is called Booting. Thereafter, a program called “Bootstrap Loader” transfers OS from hard disk into main memory. Now the OS gets loaded (Windows/Linux) and will get executed.

Booting process is of two types:

  • Cold Booting.
  • Warm Booting.

Cold Booting :
When the system starts from initial state i.e. it is switched on, we call it cold booting or Hard Booting: When the user presses the Power button, the instructions are read from the ROM to initiate the booting process.

Warm Booting :
When the system restarts or when Reset button is pressed, we call it Warm Booting or Soft Booting. The system does not start from initial state and so all diagnostic tests need not be carried out in this case. There are chances of data loss and system damage as the data might not have been stored properly.

Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II

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11th Accountancy Guide Final Accounts of Sole Proprietors – II Text Book Back Questions and Answers

Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II

I. Multiple Choice Questions

Choose the correct answer.

Question 1.
A prepayment of insurance premium will appear in __________.
a) The trading account on the debit side
b) The profit and loss account on the credit side
c) The balance sheet on the assets side
d) The balance sheet on the liabilities side
Answer:
c) The balance sheet on the assets side

Question 2.
Net profit is __________.
a) Debited to capital account
b) Credited to capital account
c) Debited to drawings account
d) Credited to drawings account
Answer:
b) Credited to capital account

Question 3.
Closing stock is valued at __________.
a) Cost price
b) Market price
c) Cost price or market price whichever is higher
d) Cost price or net realisable value whichever is lower
Answer:
d) Cost price or net realisable value whichever is lower

Question 4.
Accrued interest on investment will be shown __________.
a) On the credit side of profit and loss account
b) On the assets side of balance sheet
c) Both (a) and (b)
d) None of these
Answer:
c) Both (a) and (b)

Question 5.
If there is no existing provision for doubtful debts, provision created for doubtful debts is __________.
a) Debited to bad debts account
b) Debited to sundry debtors account
c) Credited to bad debts account
d) Debited to profit and loss account
Answer:
d) Debited to profit and loss account

II. Very Short Answer Questions

Question 1.
What are adjusting entries?
Answer:
Adjusting entries are the journal entries made at the end of the accounting period to account for items which are omitted in the trial balance and to make adjustments for outstanding and prepaid expenses and revenues accrued and received in advance.

Question 2.
What is an outstanding expense?
Answer:

  1. Expenses which have been incurred in the accounting period but not paid till the end of the accounting period are called outstanding expenses.
  2. In other words, if certain benefits or services are received during the year but payment is not made for the services received and utilized, these are termed outstanding expenses.
  3. An outstanding expense account is a representative personal account and an expense account is a nominal account.

Question 3.
What is a prepaid expense?
Answer:

  1. Prepaid expenses refer to any expense or portion of expense paid in the current accounting year but the benefit of services of which will be received in the next accounting period.
  2. They are also called unexpired expenses.
  3. Though these expenses are paid in the accounting period, they are not incurred during the accounting period.
  4. A prepaid expense account is a representative personal account.
  5. An expense account is a nominal account.

Question 4.
What are accrued incomes?
Answer:

  1. Accrued income is income or portion of income which has been earned during the current accounting year but not received till the end of that accounting year.
  2. It generally happens in the case of the amount to be received on account of commission, interest, dividend, etc.

Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II

Question 5.
What is the provision for discounts on debtors?
Answer:

  1. A cash discount is allowed by the suppliers to customers for prompt payment of the amount due either on or before the due date.
  2. Provision for discount on debtors is made on the basis of past experience at an estimated rate on sundry debtors.

III. Short Answer Questions

Question 1.
What is the need for preparing final accounts?
Answer:

  1. To record omissions in trial balance such as closing stock, interest on capital, interest on drawings, etc.
  2. To bring into account outstanding and prepaid expenses.
  3. To bring into account income accrued and received in advance.
  4. To create reserves and provisions.

Question 2.
What is meant by provision for doubtful debts? Why is it created?
Answer:
Provision for bad and doubtful debts refers to the amount set aside as a charge against profit to meet any loss arising due to bad debt in the future. The amount of doubtful debts is calculated on the basis of some percentage on debtors at the end of the accounting period after deducting further bad debts (if any). A provision for doubtful debts is created and is charged to the profit and loss account.

Question 3.
Explain how dosing stock is treated in final accounts.
Answer:
The unsold goods in the business at the end of the accounting period are termed as closing stock. As per AS-2 (Revised), the stock is valued at cost price or net realizable value, whichever is lower.
Adjusting entry
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 1
Presentation in final accounts
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 2

Question 4.
Give the adjusting entries for interest on capital and interest on drawings.
Answer:
Adjusting entry
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 3
Interest on Drawings
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 4

Question 5.
Explain the accounting treatment of bad debts, provision for doubtful debts, and provision for discount on debtors.
Answer:
Bad debts: In other words, debts which cannot be recovered or irrecoverable debts are called bad debts. It is a loss for the business and should be charged against profit.

Provision for bad and doubtful debts:

  • Provision for bad and doubtful debts refers to the amount set aside as a charge against profit to meet any loss arising due to bad debt in the future.
  • At the end of the accounting period, there may be certain debts which are doubtful, i.e., the amount to be received from debtors may or may not be received.
  • The reason may be the incapacity to pay the amount of deceit.
  • In general, based on past experience, the amount of doubtful debts is calculated on the basis of some percentage on debtors at the end of the accounting period after deducting further bad debts (if any).
  • Since the amount of loss is impossible to ascertain until it is proved bad, doubtful debts are charged against profit and loss accounts in the form of provision.
  • A provision for doubtful debts is created and is charged to the profit and loss account. When bad debts occur, it is transferred to provision for doubtful debts account and not to profit and loss account.

Provision for discount on debtors:

  • A cash discount is allowed by the suppliers to customers for prompt payment of the amount due either on or before the due date.
  • A provision created on sundry debtors for allowing such discount is called a provision for discount on debtors.

Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II

IV. Exercises

Question 1.
Pass adjusting entries for the following
a) The closing stock was valued at ₹ 5,000
b) Outstanding salaries ₹ 150
c) Insurance prepaid ₹ 450
d) ₹ 20,000 was received in advance for commission.
e) Accrued interest on investments is ₹ 1,000.
Solution::
Adjusting Entries
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 5

Question 2.
For the following adjustments, pass adjusting entries
a) Outstanding wages ₹ 5,000.
b) Depreciate machinery by ₹ 1,000.
c) Interest on capital @ 5% (Capital ₹ 20,000)
d) Interest on drawings ₹ 50
e) Write off bad debts ₹ 500
Solution:
Adjusting Entries
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 6

Question 3.
On preparing final accounts of Suresh, bad debt account has a balance of ₹ 800 and sundry debtors account has a balance of ₹ 18,000 of which ₹ 1,200 Is to be written off as further bad debts. Pass adjusting entry for bad debts. And also show how it would appear in profit and loss account and balance sheet.
Solution:
Adjusting Entries
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 7
Profit & loss account for the year ended
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 8
Balance sheet
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 9

Question 4.
The trial balance on March 31, 2016, shows the following:
Sundry debtors ₹ 30,000; Bad debts ₹ 1,200
It is found that 3% of sundry debtors is doubtful of recovery and is to be provided for. Pass journal entry for the amount of provision and also show how it would appear in the profit and loss account and balance sheet.
Solution:
Adjusting Entries
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 10
Profit & loss account for the year ended 31st March 2016
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 11
Balance sheet as of 31st March 2016
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 12

Question 5.
The trial balance of a trader on 31st December 2016 shows sundry debtors as ₹ 50,000.
Adjustments:
a) Write off ₹ 1,000 as bad debts
b) Provide 5% for doubtful debts
c) Provide 2% discount on debtors
Show how these items will appear in the profit and loss A/c and balance sheet of the trader.
Solution:
Profits loss account for the year ended 31st December 2016
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 13
Balance Sheet as of 31st December 2016
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 14

Question 6.
On 1st January 2016, the provision for doubtful debts accounts had a balance of ₹ 3,000. On December 31, 2016, sundry debtors amounted to ₹ 80,000. During the year, bad debts to be written off were ₹ 2,000. A provision for 5% was required for next year. Pass journal entries and show how these items would appear in the final accounts.
Solution:
Adjusting Entries
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 15
Profit & loss account for the year ended 31st December 2016
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 16
Balance sheet as of 31st December 2016
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 17

Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II

Question 7.
The following are the extracts from the trial balance.
Sundry debtors ₹ 30,000; Bad debts ₹ 5,000
Additional information
a) Write off further bad debts ₹ 3,000.
b) Create 10% provision for bad and doubtful debts.
You are required to pass necessary adjusting entries and show how these items will appear in profit and loss account and balance sheet.
Adjusting Entries
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 18
Profit and Loss A/c
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 19
Balance sheet
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 20

Question 8.
The following are the extracts from the trial balance
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 21
Additional information
a) Additional bad debts ₹ 3,000.
b) Keep a provision for bad and doubtful debts @ 10% on sundry debtors.
You are required to pass necessary adjusting entries and show how these items will appear in the profit and loss account and balance sheet.
Solution:
Adjusting Entries
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 22
Profit and Loss A/c
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 23
Balance sheet
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 24

Question 9.
The accounts of Lakshmi traders showed the following balance on 31st March 2016.
Sundry debtors ₹ 60,000;
Bad debts ₹ 2,000
Provision for doubtful debts ₹ 4,200
At the time of preparation of final accounts on 31st March, it was found that out of sundry debtors, ₹ 1,000 will be irrecoverable. It was decided to create a provision of 2% on debtors to meet any future possible bad debts.
Pass necessary journal entries and show how these items would appear in the final accounts.
Solution:
Adjusting Entries
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 25
Profit and Loss A/c
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 26
Balance sheet as on 31st Mar 2016
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 27

Question 10.
The following are the extracts from the trial balance.
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 28
Additional information:
a) Create a provision for doubtful debts @ 10% on sundry debtors.
b) Create a provision for discount on debtors @ 5% on sundry debtors.
You are required to pass necessary adjusting entries and show how these items will appear in the final accounts.
Solution:
Adjusting Entries
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 29
Profit and Loss A/c
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 30
Balance sheet
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 31

Question 11.
Following are the extracts from the trial balance.
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 32
Additional information:
a) Additional bad debts ₹ 1,000
b) Create a provision for doubtful debts @ 5% on sundry debtors,
c) Create a provision for discount on debtors @ 2% on sundry debtors.
You are required to pass necessary journal entries and show how these items will appear in the final accounts.
Solution:
Adjusting Entries
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 33
Profit and Loss A/c
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 34
Balance sheet as on 31st December 2016
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 35

Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II

Question 12.
The following are the extracts from the trial balance.
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 36
You are required to show how these items will appear in the profit and ioss account and balance sheet.
Solution:
Profit and Loss A/c
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 37Balance sheet
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 38

Question 13.
Prepare trading account of Archana for the year ending 31st December, 2016 from the following information
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 39
Adjustments:
a) Closing stock ₹ 1,00,000
b) Wages outstanding ₹ 12,000
c) Freight inwards paid in advance ₹ 5,000
Solution:
Trading A/c for the year ending 31st Dec 2016
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 40

Question 14.
Prepare profit and loss account of Manoj for the year ending on 31st March, 2016
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 41
Adjustments:
i) Salary outstanding ₹ 400
ii) Rent paid in advance ₹ 50
iii) Commission receivable ₹ 100
Solution:
Profit and loss A/c for the year ending 31st Mar 2016
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 42

Question 15.
From the trial balance of Sumathi and the adjustments prepare the trading and profit and loss account for the year ended 31st March 2016, and a balance sheet as on that date.
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 43
Adjustments:
a) Six months interest on the loan is outstanding.
b) Two months rent is due from the tenant, the monthly rent being ₹ 25.
c) Salary for the month of March 2016, ₹ 75 is unpaid.
d) Stock in hand on March 31, 2016, was valued at ₹ 1,030.
Solution:
Profit and loss A/c of Sumathi as 31st Dec 2016
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 44
Balance sheet as on 31st Dec 2016
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 45

Question 16.
The following trial balance was extracted from the books of Arun Traders as of 31st March 2018.
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 46
Prepare trading and profit and loss account for the year ending 31st March 2018 and balance sheet as of that date after considering the following:
a) Depreciate Plant and machinery @ 20%
b) Wages outstanding amounts to ₹ 750.
c) Half of the repairs and maintenance paid is for the next year.
d) Closing stock was valued at ₹ 15,000.
Solution:
Trading and loss account for the year ended 31st March 2018
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 47
Balance sheet for the year ending 31st March 2016.
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 48

Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II

Question 17.
The following is the trial balance of Babu as of 31st December 2016.
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 49
Prepare trading and profit and loss accounts for the year ended 31st December 2016 and a balance sheet as on that date after the following adjustments.
a) Salaries outstanding ₹ 500
b) Interest on investments receivable at 10%.
c) Provision required for bad debts is 5%.
d) Closing stock is valued at ₹ 9,900.
Solution:
Profit and loss A/c
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 50
Balance sheet for the year ended 31st December 2016.
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 51

Question 18.
From the following trial balance of Ramesh as of 31st March 2017, prepare the trading and profit and loss account and the balance sheet as of that date.
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 52
a) Closing stock was valued at ₹ 35,000
b) Unexpired advertising ₹ 250
c) Provision for bad and doubtful debts is to be increased to ₹ 3,000
d) Provide 2% for discount on debtors :
Solution:
Trading profit and loss account of Mrs. Ramesh for the year ended 31st March, 2017
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 53
Balance sheet for the year ended 31st March 2016
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 54

Question 19.
Following are the ledger balances of Devi as on 31st December, 20:6
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 55
Prepare trading and profit and loss accounts for the year ended 31st December 2016 and balance sheet as on that date.
a) Stock on 31st December 2016 ₹ 5,800.
b) Write off bad debts ₹ 500.
c) Make a provision for bad debts @ 5%.
d) Provide for discount on debtors @ 2%.
Solution:
Trading and profit and loss account of Mrs. Devi for the year ended 31st Dec 2016
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 56
The balance sheet of Mrs. Devi for the year ended 31st December 2016
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 57

Question 20.
From the following trial balance of Mohan for the year ended 31st March 2017 and additional information, prepare trading and profit and loss account and balance sheet.
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 58
Additional information:
a) Closing stock is valued at ₹ 15,500
b) Write off t 500 as bad debts and create a provision for bad debts @ 10% on debtors.
c) Depreciation @ 10% required
Solution:
Trading and profit and loss account of Mr. Mohan for the year ended 31st March 2017
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 59
Balance sheet for the year ended 31st March 2017
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 60

Question 21.
From the following t I balance of Subramaniam, prepare his trading and profit and loss account and balance sheet as on 31st December, 2016.
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 61
Take into account the following adjustments:
a) Charge interest on drawings at 8%.
b) Outstanding salaries ₹ 3,000
c) Closing stock was valued at ₹ 48,000
d) Provide for 5% interest on capital.
Solution:
Trading and profit and loss A/c of Mrs. Subramanian for the year ended 31st Dec.2016
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 62
Balance sheet for the ended 31st December 2016.
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 63

Question 22.
Prepare trading and profit and loss account and balance sheet from the following trial balance of Madan as of 31st March, 2018
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 64
Adjustments
a) The closing stock was ₹ 80,000
b) Provide depreciation on plant and machinery @ 20%
c) Write off ₹ 800 as further bad debts
d) Provide the doubtful debts @ 5% on sundry debtors
Solution:
Trading profit and loss account of Mrs.Madan for the year ended 31st March 2018.
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 65
Balance sheet for the year ended 31st March 2018.
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 66

Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II

Question 23.
From the following information prepare trading and profit and loss account and balance sheet of Kumar for the year ending 31st December 2017.
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 67
Adjustments
a) The closing stock on 31st December 2017 was valued at ₹ 3,900.
b) Carriage inwards prepaid ₹ 250
c) Rent received in advance ₹ 100
d) Manager is entitled to receive commission @ 5% of net profit after providing such commission
Solution:
Trading profit and loss a/c of Mrs.Kumar for the ended 31st December 2017
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 68
Balance sheet for the year ended 31st December 2017.
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 69

Question 24.
From the following information, prepare a trading and profit and loss account and balance sheet in the books of Sangeetha for the year ending 31st March 2018.
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 70
Adjustments
a) Stock on 31st March 2018 ₹ 14,200
b) Income tax of Sangeetha paid ₹ 800
c) Charge interest on drawings @12% p.a.
d) Provide managerial remuneration @ 10% of net profit before charging such commission.
Solution:
Trading and loss A/c of Mrs. Sangeetha for the ended 31st March 2018
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 71
Balance sheet for the year ended 31st March 2018.
 Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 72

11th Accountancy Guide Final Accounts of Sole Proprietors – II Additional Important Questions and Answers

I. Choose the correct answer.

Question 1.
If closing stock is already adjusted, adjusted purchase account and ………………. stock will appear in trial balance.
(a) Opening
(b) Closing
(c) Average
(d) None of these
Answer:
(b) Closing

Question 2.
The unsold goods in the business at the end of the accounting period are termed as __________.
a) Opening stock
b) Closing stock
c) Average stock
d) None of these
Answer:
b) Closing stock

Question 3.
When bad debts already appear in the trial balance, it is taken only to the debit side of ………………. account.
(a) Profit and Loss
(b) Balance sheet
(c) Asset side
(d) None of these
Answer:
(a) Profit and Loss

Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II

Question 4.
Unexpired expenses are also called as __________.
a) Outstanding expenses
b) Prepaid expenses
c) Accrued income
d) Income received in advance
Answer:
b) Prepaid expenses

Question 5.
All the items given in the adjustment will appear at __________ in the final account.
a) Four place
b) Three place
c) Two place
d) One place.
Answer:
c) Two place

Question 6.
The Trial balance shows bank loan ₹ 5,00,000 at 12% on 01-01-2017. Interest paid ₹ 40,000. Interest outstanding is ₹ __________ as on 31-12-2018.
a) 40,000
b) 5,40,000
c) 4,60,000
d) 20,000
Answer:
d) 20,000

Question 7.
As per Trial balance, capital as on 31.03,2018 is ₹ 5,00,000. Provide 6% Interest on capital ₹ __________.
a) 10,000
b) 20,000
c) 30,000
d) 40,000
Answer:
c) 30,000

Question 8.
Trial balance as of 31.12.2017. Shows sundry debtors t 55,000. As per given adjustments, if ₹ 5,000 is to be written off as bad debts, the provision for bad and doubtful debts at 2% will be ₹ __________.
a) 1,000
b) 1,100
c) 1,200
d) 1,300
Answer:
a) 1,000

Question 9.
The Trial balance shows Investment ₹ 3,00,000 at 10% on 61-01-2017. Income received ₹ 20,000. Accrued Interest on investment, yet to be received is ₹ __________ as on 31-12-2018.
a) 30,000
b) 10,000
c) 50,000
d) 25,000
Answer:
b) 10,000

Question 10.
__________ contributed by proprietor is a liability to the business.
a) Drawings
b) Profit
c) Loss
d) Capita
Answer:
d) Capita

Question 11.
__________ represents the number of goods withdrawn by the proprietor front the business for his personal use.
a) Drawings
b) Purchases
c) Sales
d) Capital
Answer:
a) Drawings

Question 12.
The decrease in book value of fixed assets due to usage or passage of time is called __________.
a) Bad debts
b) Depreciation
c) Closing stock
d) Capital
Answer:
b) Depreciation

Question 13.
Debts Which cannot be recovered or irrecoverable debts are called __________.
a) Bad debts
b) Depreciation
c) Closing stock
d) Capita
Answer:
a) Bad debts

Question 14.
Prepaid insurance is __________.
a) an asset
b) a liability
c) an income
d) an expense
Answer:
a) an asset

Question 15.
Wages outstanding is __________.
a) an asset
b) a liability
c) an income
d) an expense
Answer:
b) a liability

II. Short Answer Questions

Question 1.
What is closing stock?
Answer:
The unsold goods in the business at the end of the accounting period are termed dosing stock. As per AS-2 (Revised), the stock is valued at cost price or net realizable value, whichever is the tower.

Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II

Question 2.
What is Income received in advance?
Answer:
Income received in advance refers to income or portion of income received in an accounting year which is not earned in the accounting period. It is also known as unearned income or unexpired income. Though the amount is received in the current accounting year, the benefit is yet to be offered to the concerned person in the next accounting year.

Question 3.
What is Interest in the capital?
Answer:
According to the separate entity concept, business and proprietor are two separate entities. Capital contributed by the proprietor is a liability to the business. Hence, interest may be provided on capita contributed by the proprietor. It is treated as a business expense. The purpose is to know the true profit of the business.

Question 4.
What is Interest in drawings?
Answer:
Drawings represent the number of goods withdrawn by the proprietor from the business for his personal use. As business is separate from owner, interest charged on drawings, if any, is to be treated as business income.

Question 5.
What is Interest on a loan?
Answer:
Business entities may have loans borrowed from banks and other financial institutions, private money lenders, etc. If any interest is payable on the loan and not yet provided at the time of preparation of the trial balance, it is necessary to provide for outstanding interest on the loan. It is an outstanding expense.

Question 6.
What is Interest in investment?
Answer:
Business entitles may have investments in outside securities carrying a specified rate of interest. If interest is due but not yet received, adjustment is to be made for the same in the accounting records before preparation of final accounts. Interest receivable on any Investments in the form of shares, deposits, etc made outside the business is called accrued interest It is an accrued income.

Question 7.
What is Depreciation?
Answer:
The decrease in book value of fixed assets due to usage or passage of time is called depreciation. It is a loss to the business. Therefore, it must be written off from the value of asset. Generally, a certain percentage on the value of the asset is calculated as the amount of depreciation.

Question 8.
What is bad debt?
Answer:
In other words, debts which cannot be recovered or irrecoverable debts are called bad debts. It is a loss for the business and should be charged against profit.

Question 9.
Write notes on Provision for bad and doubtful debts?
Answer:
1. Provision for bad and doubtful debts refers to the amount set aside as a charge against profit to meet any loss arising due to bad debt in the future. At the end of the accounting period, there may be certain debts which are doubtful, i.e., the amount to be received from debtors may or may not be received.

2. In general, based on past experience, the amount of doubtful debts is calculated on the basis of some percentage on debtors at the end of the accounting period after deducting further bad debts.

Question 10.
Write notes on Provision for discount on creditors?
Answer:
Similar to the cash discount allowed to debtors, the firm may have a chance to receive the cash discount from the creditors for prompt payment. Provision for discount on Creditors is calculated at a certain percentage on Sundry Creditors.

III. Additional Sums

Question 1.
From the following Trial Balance prepare the Trading and Profit and Loss Account for the year ended 31st December 2017 and a Balance Sheet as of that date
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 73
Adjustments
i. Closing Stock ₹ 9,800
ii. Salaries outstanding ₹ 600
iii. Rent paid in advance ₹ 400
iv. Depreciate Machinery at 10%
v. Bad debts written off ₹ 500
Solution:
Trading, Profit, and Loss Account for the year ended 3 .12.2017
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 74
Balance Sheet as on 31.12.2017
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 75

Question 2.
From the following trial balance of Shri, prepare Trading and Profit and Loss account for the year ended December 31st, 2017, and a balance sheet as on that date.
Adjustments
1. Stock on 31.12.2017 ₹ 4,900
2. Salaries unpaid ₹ 300
3. Rent paid in advance ₹ 200
4. Insurance prepaid ₹ 90
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 76
Solution:
Trading, Profit and loss Account for the year ended 31.12.2017
 Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 77
Balance Sheet as on 31.12.2017
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 78

Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II

Question 3.
From the following trial balance prepare trading and profit and loss account for the year ended 2016 and balance sheet as on that data
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 79
Adjustments
1. Closing Stock ₹ 9,800
2. Salaries Outstanding ₹ 600
3. Rent paid in advance ₹ 400
4. Depreciate Machinery at 10%
5. Bad debts are written off ₹ 500
Solution:
Trading, Profit, and Loss Account for the year ended 31.12.2017
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 80
Balance Sheet as on 31.12.2017
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 81

Question 4.
Pass necessary adjusting entries for the following adjustments.
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 81a
Solution:
Adjustment Entries
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 82

Question 5.
Pass necessary adjusting entries for the following adjustments.
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 82a
Solution:
Journal Entries
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 83

Question 6.
The Trial balance as of 31st March 2004 shows the following.
Sundry debtors – 40800
Bad debts are written off – 1400
Adjustment: Written off ₹ 800/- bad debts.
Solution:
Journal Entries
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 84
Profit and loss account for the year ending 31st March 2004
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 85
Balance sheet as on 31st March 2004.
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 86

Question 7.
The following items are found in the Trial Balance of Mr. Vivekanandan as of 31st March 2004.
Sundry debtors – 64000
Bad debts – 1200
Provision for bad and doubtful debts – 2800
Adjustments:
Provide for bad and doubtful debts at 5% on sundry debtors give necessary entries and show how these items will appear in the final accounts.
Solution:
Transfer of bad debts
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 87
Adjusting Entry
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 88
Profit and Loss account for the period ended 31st March 2004
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 89
Balance sheet as on 31st March 2004
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 90

Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II

Question 8.
Following are the balances extracted from the Trial Balance Mr. Mohan as of 31st March 2002.
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 91
Adjustments
Create provision for bad and doubtful debts @ 5% on sundry debtors pass adjusting entry and show how these items will appear final accounts.
Solution:
Adjusting Entry
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 92
Profit and loss Account for the Year ending 31st March 2002
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 93
Balance sheet as of 31st March 2002
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 94

Question 9.
Prepare trading account from the following ledger balance presented by P. Sen as on 31st March 2016
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 95
Additional Information
a) Stock on 31st March 2016, ₹ 20,000
b) Outstanding wages amounted to ₹ 4,000
c) Gas and Fuel paid in advanced ₹ 1000
Solution:
Trading account for the year ended 31st March 2016
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 96

Question 10.
From the following particular presented by Thilak for the year ended 31st March 2017 Prepare profit and loss A/c
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 97
Adjustments
1. Outstanding salaries amounted to ₹ 4,000
2. Rent paid for 11 month
3. Interest due but not received amounted to ₹ 2,000
4. Prepaid insurance amounted to ₹ 2,000
5. Depreciate buildings by 10%
6. Further bad debts amounted to ₹ 3000 and make a provision for bad debts @ 5% on sundry debtors
7. Commission received in advance amounted to ₹ 2,000
Solution:
Profit and loss account for the year ended 31st Mar 2017
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 98

Question 11.
From the following balance as of 31st December 2017, prepare a profit and loss account
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 99
Adjustments
a) Rent accrued by not yet received ₹ 500
b) Fire insurance premium prepaid to the extent of ₹ 1,500
c) Provide manages commission at 10% on profits before charging such commission.
Solution:
Profit and loss account for the year ended 31st December 2017
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 100
Working Note
Manager’s commission = Net profit before charaing commission x \(\frac{\text { Rate of commission }}{100}\)
Net profit = 55,500 – (18,000 + 12,000 + 8,000 + 2,500 + 5,000 ) = ₹ 10,000
Manager’s commission = 10,000 x 10/100 = ₹ 1,000

Question 12.
From the following particulars, prepare the balance sheet of Madhu, for the year ended 31st March 2018.
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 101
Adjustment
a. Outstanding liabilities: Salaries ₹ 10,000, Wages ₹ 20,000, Interest on bank overdraft ₹ 3000 Interest on bank loan ₹ 6,000
b. Provide interest on capital @ 10% P.a
c. Bad debts amounted to ₹ 10,000 and make a provision for bad and doubtful debts 10% on sundry debtors
d. Closing stock amounted to ₹ 1,20,000
e. Depreciate vehicles @10% P.a
Net profit for the year amounted to ₹ 96,000 after considering all the above adjustments.
Solution:
Balance Sheet of Madhu as on 31st Mar, 2018
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 102

Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II

Question 13.
The trial balance shows on 31-03-2005 sundry debtors ₹ 56,000
Adjustments
a) Bad debts to be written off ₹ 6,000
b) Provision for bad and doubtful debts by 5%
c) Provision discount on debtors at 2% pass adjusting entries and show how these items will appear in the final accounts.
Solution:
Adjusting Entry
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 103
Profit and loss A/c
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 104
Balance sheet as on 31-03-2005
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 105

Question 14.
The trial balance shows the following as on 31-03-1998
Capital ₹ 5,00,000
Drawings ₹ 50,000
Charge interest on drawings at 5% pass adjusting and transfer entry his will appear in final accounts.
Solution:
Adjusting Entry
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 106
Transfer Entry
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 107
Balance sheet as on 31, March,1998
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 108

Question 15.
The following balance has been extracted from Mrs. Padma as of 31st March 2002.
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 109
Adjustments
1) Closing stock was valued at ₹ 80,000
2) Provide for accrued on investment ₹ 500
3) Commission received in advance ₹ 400
4) A provision for bad and doubtful debts is to be created to the extent of 5% on sundry debtors
5) Sundry creditors is to the created an extent of 2% on sundry creditors
Solution:
Trading and profit loss A/c of Mrs. Padma for the year ended 31st March 2002
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 110
Balance sheet as on Mrs. Padma 31st March 2002.
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 111

Question 16.
The following are the balance extracted from the books of Mrs. Nandhini as 31-03-2002
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 112
Adjustments:
1) Closing stock ₹ 40,000
2) Interest on capital 6% to be provided
3) Interest on drawings 5% to be provided
4) Wages yet to be paid ₹ 1,000
5) Rent prepaid ₹ 900
Solution:
Trading, profit loss account of Mrs. Nandhini for the year ended 31st March 2002
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 113
The balance sheet of Mrs. Nandhini as of 31st March 2002.
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 114

Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II

Question 17.
From the following trial balance of Thiru. Rehman as of 31st March 2016, prepare trading profit and loss A/c Balance sheet trading to the adjustments.
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 115
Adjustments
a) Stock on 31.3.1995 was ₹ 6,800
b) Salary outstanding ₹ 1,500
c) Insurance prepaid ₹ 150
d) Depreciate machinery @ 10% and patent 20%
e) Create a provision of 2% on debtors bad debts
Solution:
Trading, profit, and loss A/c of Thiru. Rehman for the year ended 31 March 2016
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 116
Balance sheet as of Thiru Rahaman 31st March 2016
Samacheer Kalvi 11th Accountancy Guide Chapter 13 Final Accounts of Sole Proprietors – II 117

Samacheer Kalvi 11th Business Maths Guide Chapter 5 Differential Calculus Ex 5.2

Students can download 11th Business Maths Chapter 5 Differential Calculus Ex 5.2 Questions and Answers, Notes, Samcheer Kalvi 11th Business Maths Guide Pdf helps you to revise the complete Tamilnadu State Board New Syllabus, helps students complete homework assignments and to score high marks in board exams.

Tamilnadu Samacheer Kalvi 11th Business Maths Solutions Chapter 5 Differential Calculus Ex 5.2

Samacheer Kalvi 11th Business Maths Differential Calculus Ex 5.2 Text Book Back Questions and Answers

Question 1.
Evaluate the following:
Samacheer Kalvi 11th Business Maths Guide Chapter 5 Differential Calculus Ex 5.2 Q11
Solution:
(i) \(\lim _{x \rightarrow 2} \frac{x^{3}+2}{x+1}\)
Samacheer Kalvi 11th Business Maths Guide Chapter 5 Differential Calculus Ex 5.2 Q1

(ii) \(\lim _{x \rightarrow \infty} \frac{2 x+5}{x^{2}+3 x+9}\)
Samacheer Kalvi 11th Business Maths Guide Chapter 5 Differential Calculus Ex 5.2 Q1.1
[Takeout x from numerator and take x2 from the denominator]
Samacheer Kalvi 11th Business Maths Guide Chapter 5 Differential Calculus Ex 5.2 Q1.2

(iii) \(\lim _{x \rightarrow \infty} \frac{\Sigma n}{n^{2}}\)
Samacheer Kalvi 11th Business Maths Guide Chapter 5 Differential Calculus Ex 5.2 Q1.3

(iv) \(\lim _{x \rightarrow 0} \frac{\sqrt{1+x}-\sqrt{1-x}}{5 x}\)
Samacheer Kalvi 11th Business Maths Guide Chapter 5 Differential Calculus Ex 5.2 Q1.4

(v) \(\lim _{x \rightarrow a} \frac{x^{\frac{5}{8}}-a^{\frac{5}{8}}}{x^{\frac{2}{3}}-a^{\frac{2}{3}}}\)
Samacheer Kalvi 11th Business Maths Guide Chapter 5 Differential Calculus Ex 5.2 Q1.5
[Divide both numerator and denominator by x – a; \(\lim _{x \rightarrow a} \frac{x^{n}-a^{n}}{x-a}=n a^{n}\)]
Samacheer Kalvi 11th Business Maths Guide Chapter 5 Differential Calculus Ex 5.2 Q1.6

(vi) \(\lim _{x \rightarrow 0} \frac{\sin ^{2} 3 x}{x^{2}}\)
Samacheer Kalvi 11th Business Maths Guide Chapter 5 Differential Calculus Ex 5.2 Q1.7

Samacheer Kalvi 11th Business Maths Guide Chapter 5 Differential Calculus Ex 5.2

Question 2.
If \(\lim _{x \rightarrow a} \frac{x^{9}-a^{9}}{x-a}=\lim _{x \rightarrow 3}(x+6)\), find the value of a.
Solution:
\(\lim _{x \rightarrow a} \frac{x^{9}-a^{9}}{x-a}=\lim _{x \rightarrow 3}(x+6)\)
9 . a9-1 = 3 + 6
9 . a8 = 9
a8 = 1
Taking squareroot on bothsides, we get
\(\left(a^{8}\right)^{\frac{1}{2}}\) = ±1
a4 = ±1
But a4 = -1 is imposssible.
∴ a4 = 1
Again taking squareroot, we get
\(\left(a^{4}\right)^{\frac{1}{2}}\) = ±1
a2 = ±1
a2 = -1 is imposssible
∴ a2 = 1
Again taking positive squareroot, a = ±1

Samacheer Kalvi 11th Business Maths Guide Chapter 5 Differential Calculus Ex 5.2

Question 3.
If \(\lim _{x \rightarrow 2} \frac{x^{n}-2^{n}}{x-2}=448\), then find the least positive integer n.
Solution:
Samacheer Kalvi 11th Business Maths Guide Chapter 5 Differential Calculus Ex 5.2 Q3
Samacheer Kalvi 11th Business Maths Guide Chapter 5 Differential Calculus Ex 5.2 Q3.1

Question 4.
If f(x) = \(\frac{x^{7}-128}{x^{5}-32}\), then find \(\lim _{x \rightarrow 2} f(x)\)
Solution:
\(\lim _{x \rightarrow 2} f(x)\)
Samacheer Kalvi 11th Business Maths Guide Chapter 5 Differential Calculus Ex 5.2 Q4

Samacheer Kalvi 11th Business Maths Guide Chapter 5 Differential Calculus Ex 5.2

Question 5.
Let f(x) = \(\frac{a x+b}{x+1}\), if \(\lim _{x \rightarrow 0} f(x)=2\) and \(\lim _{x \rightarrow \infty} f(x)=1\), then show that f(-2) = 0
Solution:
Samacheer Kalvi 11th Business Maths Guide Chapter 5 Differential Calculus Ex 5.2 Q5
Samacheer Kalvi 11th Business Maths Guide Chapter 5 Differential Calculus Ex 5.2 Q5.1
Hence Proved.

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DEEPAKNTR Pivot Point Calculator

Samacheer Kalvi 11th Chemistry Guide Chapter 15 Environmental Chemistry

Tamilnadu State Board New Syllabus Samacheer Kalvi 11th Chemistry Guide Pdf Chapter 15 Environmental Chemistry Text Book Back Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 11th Chemistry Solutions Chapter 15 Environmental Chemistry

11th Chemistry Guide Environmental Chemistry Text Book Back Questions and Answers

Textbook Evaluation:

I. Choose the best answer:

Question 1.
The gaseous envelope around the earth is known as atmosphere. The region lying between an altitudes of 11 – 50 km is _______.
(a) Troposphere
(b) Mesosphere
(c) Thermosphere
(d) Stratosphere
Answer:
(d) Stratosphere

Question 2.
Which of the following belongs to secondary air pollutant?
(a) Hydrocarbon
(b) Peroxy acetyl nitrate
(c) Carbon monoxide
(d) Nitric oxide
Answer:
(a) Hydrocarbon

Question 3.
Which of the following is natural and human disturbance in ecology?
(a) Forest fire
(b) Floods
(c) Acid rain
(d) Green house effect
Answer:
(b) Floods

Question 4.
Bhopal Gas Tragedy is a case of _______.
(a) thermal pollution
(b) air pollution
(c) nuclear pollution
(d) land pollution
Answer:
(c) nuclear pollution

Question 5.
Haemoglobin of the blood forms carboxy haemoglobin with
(a) Carbon dioxide
(b) Carbon tetra chloride
(c) Carbon monoxide
(d) Carbonic acid
Answer:
(c) Carbon monoxide

Samacheer Kalvi 11th Chemistry Guide Chapter 15 Environmental Chemistry

Question 6.
Which sequence for green house gases is based on GWP?
(a) CFC > N2O > CO2 > CH4
(b) CFC > CO2 > N2O > CH4
(c) CFC > N2O > CH4 > CO2
(d) CFC > CH4 > N2O > CO2
Answer:
(b) CFC > CO2 > N2O > CH4

Question 7.
Photo chemical smog formed in congested metropolitan cities mainly consists of
(a) Ozone, SO2 and hydrocarbons
(b) Ozone, PAN and NO2
(c) PAN, smoke and SO2
(d) Hydrocarbons, SO2 and CO2
Answer:
(d) Hydrocarbons, SO2 and CO2

Question 8.
The pH of normal rain water is
(a) 6.5
(b) 7.5
(c) 5.6
(d) 4.6
Answer:
(c) 5.6

Question 9.
Ozone depletion will cause
(a) forest fires
(b) eutrophication
(c) bio magnification
(d) global warming
Answer:
(a) forest fires

Question 10.
_______ is considered to be ozone friendly substitute for CFC’S
(a) HFC (Hydro Fluro Carbon)
(b) Halons
(c) PAN (Peroxy acetyl nitrate)
(d) PAH (Polycyclic aromatic hydrocarbon)
Answer:
(d) PAH (Polycyclic aromatic hydrocarbon)

Samacheer Kalvi 11th Chemistry Guide Chapter 15 Environmental Chemistry

Question 11.
Identify the wrong statement in the following.
(a) The clean water would have a BOD value of less than 5 ppm
(b) Greenhouse effect is also called Global warming
(c) Minute solid particles in air are known as particulate pollutants
(d) Biosphere is the protective blanket of gases surrounding the earth
Answer:
(c) Minute solid particles in air are known as particulate pollutants

Question 12.
Living in the atmosphere of CO is dangerous because it
(a) combines with O2 present inside to form CO2
(b) Reduces organic matter of tissues
(c) Combines with hemoglobin and makes it incapable to absorb oxygen
(d) Dries up the blood
Answer:
(c) Combines with hemoglobin and makes it incapable to absorb oxygen

Question 13.
World Ozone layer protection Day is celebrated in ________.
(a) June 5
(b) Nov – 19
(c) Sep – 16
(d) Jan – 26
Answer:
(c) Sep – 16

Question 14.
Release of oxides of nitrogen and hydrocarbons into the atmosphere by motor vehicles is prevented by using
(a) grit chamber
(b) scrubbers
(c) trickling filters
(d) catalytic converters
Answer:
(b) scrubbers

Question 15.
Biochemical oxygen Demand value less than 5 ppm indicates a water sample to be
(a) highly polluted
(b) poor in dissolved oxygen
(c) rich in dissolved oxygen
(d) low COD
Answer:
(d) low COD

Samacheer Kalvi 11th Chemistry Guide Chapter 15 Environmental Chemistry

Question 16.
Match the List I with List-II and select the correct answer using the code given below the lists:

List I List II
A. Depletion of the ozone layer 1. CO2
B. Acid rain 2. NO
C. Photochemical smog 3. SO2
D. Greenhouse effect 4. CFC

Code:
Samacheer Kalvi 11th Chemistry Guide Chapter 15 Environmental Chemistry 1
Answer:
(a)

Question 17.
Match List I with List-II and select the correct answer using the code given below the lists.

List I List II
A. Stone leprosy 1. CO
B. Biological magnification 2. Greenhouse gases
C. Global warming 3. Acid rain
D. Combination with hemoglobin 4. DDT

Code:
Samacheer Kalvi 11th Chemistry Guide Chapter 15 Environmental Chemistry 1
Answer:
(d)

Question 18.
Assertion (A):
If the BOD level of water in a reservoir is more than 5 pm it is highly polluted.
Reason (R):
High biological oxygen demand means the high activity of bacteria in water.
(i) Both (A) and (R) are correct and (R) is the correct explanation of (A)
(ii) Both (A) and (R) are correct and (R) is not the correct explanation of (A)
(iii) Both (A) and (R) are not correct
(iv) (A) is correct but (R) is not correct
(a) i
(b) ii
(c) iii
(d) iv
Answer:
(a) i

Question 19.
Assertion (A):
Excessive use of chlorinated pesticides causes soil and water pollution.
Reason (R):
Such pesticides are non – biodegradable.
(i) Both (A) and (R) are correct and (R) is the correct explanation of (A)
(ii) Both (A) and (R) are correct and (R) is not the correct explanation of (A)
(iii) Both (A) and (R) are not correct
(iv) (A) is correct but (R) is not correct
(a) i
(b) ii
(c) iii
(d) iv
Answer:
(a) i

Question 20.
Assertion (A):
Oxygen plays a key role in the troposphere
Reason (R):
The troposphere is not responsible for all biological activities
(i) Both (A) and (R) are correct and (R) is the correct explanation of (A)
(ii) Both (A) and (R) are correct and (R) is not the correct explanation of (A)
(iii) Both (A) and (R) are not correct
(iv) (A) is correct but (R) is not correct
(a) i
(b) ii
(c) iii
(d) iv
Answer:
(b) ii

Samacheer Kalvi 11th Chemistry Guide Chapter 15 Environmental Chemistry

II. Write brief answer to the following questions:

Question 21.
Dissolved oxygen in water is responsible for aquatic life. What processes are responsible for the reduction in dissolved oxygen in water?
Answer:

  • Organic matter such as leaves, grass, trash can pollute water. Microorganisms present in water can decompose this organic matter and consume dissolved oxygen in water.
  • Eutrophication is a process by which water bodies receive excess nutrients that stimulates excessive plant growth. This enhanced plant growth in water bodies is called algal bloom.
  • The growth of algae in extreme abundance covers the water surface and reduces the oxygen concentration in water. Thus, bloom-infeded water inhibits the growth of others. living organisms in the water body.
  • This process in which the nutrient-rich water support a dense plant population kills animal life by depriving it of oxygen and results in loss of biodiversity is known as eutrophication.

Question 22.
What would happen, if the greenhouse gases were totally missing in the earth’s atmosphere?
Answer:
The solar energy radiated back from the earth’s surface is absorbed by the greenhouse gases. (CO2, CH4, O3, CFCs) are present near the earth’s surface. They heat up the atmosphere near the earth’s surface and keep it warm.

As a result of these, there is the growth of vegetation that supports life. In the absence of this effect, there will be no life of both plant and animal on the surface of the earth.

Question 23.
Define smog.
Answer:

  • Smog is a combination of smoke and fog which form droplets that remain suspended in the air.
  • Smog is a chemical mixture of gases that forms a brownish-yellow haze. It mainly consists of ground-level ozone, oxides of nitrogen, volatile organic compounds, SO2, acidic aerosols and some other gases.

Question 24.
Which is considered to be the earth’s protective umbrella? Why?
Answer:
At high altitudes to the atmosphere consists of a layer of ozone (O3) which acts as an umbrella or shield for harmful UV radiations. It protects us from harmful effects such as skin cancer. UV radiation can convert molecular oxygen into ozone as shown in the following reaction.
O2(g) Samacheer Kalvi 11th Chemistry Guide Chapter 15 Environmental Chemistry 12 O(g) + O(g)
O(g) + O2(g) Samacheer Kalvi 11th Chemistry Guide Chapter 15 Environmental Chemistry 12 O3(g)

Question 25.
What are degradable and non – degradable pollutants?
Answer:
The pollutants are classified as bio-degradable and non-biodegradable pollutants.

Bio-degradable pollutants:
The pollutants which can be easily decomposed by the natural biological processes are called bio-degradable pollutants.
Example:
plant wastes, animal wastes, etc.

Non-bio-degradable pollutants:
The pollutants which cannot be decomposed by the natural biological processes are called Non-bio-degradable
pollutants.
Examples:
Metal wastes (mainly Hg and Pb), D.D.T, plastics, nuclear wastes, etc.,
These pollutants are harmful to living organisms even in low concentrations. As they are not degraded naturally, it is difficult to eliminate them from our environment.

Samacheer Kalvi 11th Chemistry Guide Chapter 15 Environmental Chemistry

Question 26.
From where does ozone come in the photochemical smog?
Answer:
NO2 Samacheer Kalvi 11th Chemistry Guide Chapter 15 Environmental Chemistry 2 NO + (O)
O3 are strong oxidizing agent and can react with unburnt hydrocarbons in polluted air to form formaldehyde, acrolein and peroxy acetyl nitrate (PAN).

Question 27.
A person was using water supplied by corporation. Due to shortage of water he started using underground water. He felt laxative effect. What could be the cause?
Answer:
Drinking water containing moderate level of sulphatcs is harmless. But excessive concentration (>500 ppm) of suiphates in drinking water causes laxative effect.

Question 28.
What is green chemistry?
Answer:
Efforts to control environmental pollution resulted in development of science for synthesis of chemicals favorable to environment which is called green chemistry. Green chemistry means science of environmentally favorable chemical synthesis.

Question 29.
Explain how does greenhouse effect cause global warming.
Answer:
Greenhouse effect may be defined as the heating up of the earth surface due to trapping of infrared radiations reflected by earth’s surface by CO2 layer in the atmosphere”. The heating up of earth through the greenhouse effect is called global warming.

Without the heating caused by the greenhouse effect, Earth’s average surface temperature would be only about -18 °C (CPF). Although the greenhouse effect is a naturally occurring phenomenon, it is intensified by the continuous emission of greenhouse gases into the atmosphere.

During the past 100 years, the amount of carbon dioxide in the atmosphere increased by roughly 30 percent and the amount of methane more than doubled. If these trends continue, the average global temperature will increase which can lead to melting of polar ice caps and flooding of low lying areas. This will increase incidence of infectious diseases like dengue, malaria etc.

Question 30.
Mention the standards prescribed by BIS for quality of drinking water.
Answer:
Standard characteristics prescribed for deciding the quality of drinking water by BIS, in 1991 are shown in Table.
Samacheer Kalvi 11th Chemistry Guide Chapter 15 Environmental Chemistry 3

Samacheer Kalvi 11th Chemistry Guide Chapter 15 Environmental Chemistry

Question 31.
How does classical smog differ from photochemical smog?
Answer:
Classical smog:

  • Classical smog is caused by coal smoke and fog.
  • It occurs in cold humid climate.
  • The chemical composition is the mixture of SO2, SO3 gases and humidity.
  • Chemically it is reducing in nature because of high concentration of SO, and so it is also called reducing smog.
  • It is primarily responsible for acid rain.
  • It also causes bronchial irritation.

Photochemical smog:

  • Photochemical smog is cause by photochemical oxidants.
  • It occurs in warm, dry and sunny climate.
  • The chemical composition is the mixture of NO2 and O3 gases.
  • Chemically it is oxidising in nature because of high concentration of oxidising agents such as NO2 and O3
  • and so it is also called oxidising smog.
  • It causes irritation to eyes, skin and lungs and increase the chances of asthma.
  • It causes corrosion of metals, stones

Question 32.
What are particulate pollutants? Explain any three.
Answer:
1. Particulate pollutants are small solid particles and liquid droplets suspended in air. Many of particulate pollutants are hazardous.
Examples: dust, pollen, smoke, soot and liquid droplets (aerosols) etc,

2. Smoke particulate consists of solid particles (or) mixture of solid and liquid particles formed by the combustion of organic matter.
For example, cigarette smoke, oil smoke, smokes from burning fossil fuel, garbage and dry leaves.

3. Dust composed of fine solid particles produced during crushing and grinding of solid materials.
For example, sand from sandblasting, sawdust from woodworks, cement dust from cement factories and fly ash from power generating units.

Question 33.
Even though the use of pesticides increases crop production, they adversely affect the living organisms. Explain the function and the adverse effects of the pesticides.
Answer:
Pesticides are the chemicals that are used to kill or stop the growth of unwanted organisms. But these pesticides can affect the health of human beings. Pesticides are classified as
(a) insecticides,
(b) Fungicides and
(c) Herbicides.

(a) Insecticides:
Insecticides like DDT, BHC, Aidrin can stay in soil for a long period of time and are absorbed by soil. They contaminate root crops like carrot, radish.

(b) Fungicides:
Organomercury compounds dissociate in soil to produce mercury which is highly toxic.

(c) Herbicides:
They are used to control unwanted plants and are also known as weed killers. Eg, Sodium chlorate, sodium nitrate. They are toxic to mammals.

Question 34.
Ethane burns completely in air to give CO2, while in a limited supply of air gives CO. The same gases are found in automobile exhaust. Both CO and CO2 are atmospheric pollutants.
Answer:
The major pollutants of oxides of carbon are carbon monoxide and carbon dioxide.

(i) Carbon Monoxide:
Carbon monoxide is a poisonous gas produced as a result of incomplete combustion of coal are firewood. It is released into the air mainly by. automobile exhaust. It binds with haemoglobin and form carboxy haemoglobin which impairs normal oxygen transport by blood and hence the oxygen carrying capacity of blood is reduced. This oxygen deficiency results in headache, dizziness, tension, Loss of consciousness, blurring of eye sight and cardiac arrest.

(ii) Carbon dioxide:
Carbon dioxide is released into the atmosphere mainly by the process of respiration, burning of fossil fuels, forest fire, decomposition of limestone in cement industry etc.

Green plants can convert CO2 gas in the atmosphere into carbohydrate and oxygen through a process called photosynthesis. The increased CO2 level in the atmosphere is responsible for global warming. It causes headache and nausea.

Question 35.
On the basis of chemical reactions involved, explain how do CFC’s cause depletion of ozone layer in stratosphere?
Answer:
In the presence of uv radiation, CFC’s break up into chlorine free radical
CF2Cl2 Samacheer Kalvi 11th Chemistry Guide Chapter 15 Environmental Chemistry 4 CF2Cl + Cl
CFCl3 Samacheer Kalvi 11th Chemistry Guide Chapter 15 Environmental Chemistry 4 CFCl2 + Cl
Cl + O3 → ClO + O2
ClO + O → Cl + O2

Chlorine radical is regenerated in the course of reaction. Due to this continuous attack of Cl thinning of Ozone layer takes place which leads to formation of the ozone hole.

It is estimated that for every reactive chlorine atom generated in the stratosphere 1,00,000 molecules of ozone are depleted.

Samacheer Kalvi 11th Chemistry Guide Chapter 15 Environmental Chemistry

Question 36.
How is acid rain formed? Explain its effect.
Answer:
1. Rainwater has a pli of 5.6 due to the dissolution of CO., into it. Oxides of sulphur and nitrogen in the atmosphere may be absorbed by droplets of water that make up the clouds and get chemically converted into sulphuric acid and nitric acid. Due to this, the pH of rainwater drops below the level of 5.6. Hence it is called acid rain.

2. Acid rain is a by-product of sulphur and Nitrogen oxides in the atmosphere. Burning of fossil fuels in power stations, furnaces and petrol, diesel in motor engines produce SO2 and NO2 gases. They are converted into H2SO4 and HNO3 by the reaction with oxygen and water.

3. 2SO2 + O3 + 2H2O → 2H2SO4
4NO2 + O2+ 2H2O → 4HNO3

Harmful effects of acid rain:
1. Acid rain causes damage to buildings made us of marbles. This attack on marble is termed as stone leprosy.
CaCO3 + H2SO2 CaSO4 + H2O + CO2

2. Acid rain affects plant and animal life in aquatic ecosystem.

3. It is harmful For agriculture, as it dissolves in the earth and removes the nutrients needed for the growth of plants.

4. It corrodes water pipes resulting in the leaching of heavy metals such as iron, lead and copper into drinking water which has toxic effects.

5. it causes respiratory ailments in humans and animals.

Question 37.
What is sewage? What are the major steps involved in the treatment of sewage waste?
Answer:
Objectives of wastewater treatment:

  1. To convert harmful compounds into harmless compounds.
  2. To eliminate the offensive smell.
  3. To remove the solid content of the sewage.
  4. To destroy the disease-producing microorganisms.

Treatment process:
The sewage (or) wastewater treatment process involves the following steps.

I. Preliminary Treatment:
In this treatment, coarse solids and suspended impurities are removed by passing the wastewater through bar and mesh screens.

II. Primary treatment (or) Settling process:
In this treatment, greater proportion of the suspended inorganic and organic solids are removed from the liquid sewage by settling. In order to facilitate quick settling coagulants like alum, ferrous sulphate are added. These produce large gelatinous precipitates, which entrap finely divided organic matter and settle rapidly.
Al2(SO4)3 + 6H2O → 2Al(OH)3 ↓ + 3H2SO4

III. Secondary (or) biological treatment:
In this treatment, biodegradable organic impurities are removed by aerobic bacteria. It removes upto 90 % of the oxygen-demanding wastes. This is done by trickling filter or activated sludge process.

(a) Trickling filter process:
It is a circular tank and is filled with either coarse or crushed rock. Sewage is sprayed over this bed by means of slowly rotating arms.
Samacheer Kalvi 11th Chemistry Guide Chapter 15 Environmental Chemistry 5

When sewage starts percolating downwards, microorganisms present in the sewage grow on the surface of filtering media using organic material of the sewage as food. After completion of aerobic oxidation the treated sewage is taken to the settling tank and the sludge is removed. This process removes about 80 – 85 % of BOD.

(b) Activated sludge process:

Activated sludge is biologically active sewage and it has a large number of aerobic bacterias, which can easily oxidize the organic impurities.

The sewage effluent from primary treatment is mixed with the required amount of activated sludge. Then the mixture is aerated in the aeration tank. Under this condition, organic impurities of the sewage get oxidized rapidly by the microorganisms.
Samacheer Kalvi 11th Chemistry Guide Chapter 15 Environmental Chemistry 6

After aeration, the sewage is taken to the sedimentation tank. Sludges settle down in this tank, called activated sludge, a portion of which is used for seeding fresh batch of the sewage. This process removes about 90-95 % of BOD.

IV. Tertiary treatment:
After the secondary treatment, the sewage effluent has a lower BOD (25 ppm), which can be removed by the tertiary treatment process.

In the tertiary treatment, the effluent is introduced into a flocculation tank, where lime is added to remove phosphates. From the flocculation tank the effluent is led to ammonia stripping tower, where pH is maintained to 11 and the NH4+ is converted to gaseous NH3. Then the effluent is allowed to pass through activated charcoal column, where minute organic wastes are absorbed by charcoal. Finally the effluent water is treated with disinfectant (chlorine).

V. Disposal of sludge:
This is the last stage in the sewage treatment. Sludge formed from different steps can be disposed by

  1. dumping into low – lying areas,
  2. burning of sludge (incineration),
  3. dumping into the sea,
  4. using it as low grade fertilizers.

Samacheer Kalvi 11th Chemistry Guide Chapter 15 Environmental Chemistry 7

Samacheer Kalvi 11th Chemistry Guide Chapter 15 Environmental Chemistry

Question 38.
Differentiate the following:
(i) BOD and COD
(ii) Viable and non-viable particulate pollutants.
Answer:
(i) BOD and COD Biochemical oxygen demand (BOD):
The total amount of oxygen in milligrams consumed by microorganisms in decomposing the waste in one litre of water at 200°C for a period of 5 days is called biochemical oxygen demand (BOD) and its value is expressed in ppm. BOD is used as a measure of degree of water pollution. Clean water would have BOD value less than 5 ppm whereas highly polluted water has BOD value of 17 ppm or more.

Chemical Oxygen Demand (COD):
BOD measurement takes 5 days so another parameter called the Chemical Oxygen Demand (COD) is measured. Chemical oxygen demand (COD) is defined as the amount of oxygen required by the organic matter in a sample of water for its oxidation by a strong oxidising agent like K2Cr2O7 in acid medium for a period of 2 hrs.

(ii) Viable and non – viable particulate pollutants:

Viable particulates:
The viable particulates are the small size living organisms such as bacteria, fungi, moulds, algae, etc. which are dispersed in air. Some of the fungi cause allergy in human beings and diseases in plants.

Non-viable particulates:
The non- viable particulates are small solid particles and liquid droplets suspended in air. They help in the transportation of viable particles. There are four types of non-viable particulates in the atmosphere.
Example:
Smoke, Dust, Mists, Fumes.

Question 39.
Explain how oxygen deficiency is cause by carbon monoxide in our blood? Give its effect.
Answer:

  1. Carbon monoxide binds with haemoglobin and form carboxyhemoglobin which impairs normal oxygen transport by blood and hence the oxygen-carrying capacity of blood is reduced.
  2. This oxygen deficiency results in headache, dizziness, tension, loss of consciousness, blurring of eyesight and cardiac arrest.

Question 40.
What are the various methods you suggest to protect our environment from pollution?
Answer:
Methods to control environmental pollution:

  • Waste management Environmental pollution can be controlled by proper disposal of wastes.
  • Recycling A large number of disposed waste materials can be reuse by recycling the waste, thus it reduces the landfill.
  • By substitution of less toxic solvents for highly toxic ones are used in industrial processes.
  • By growing more trees.
  • By using fuels with lower sulphur content.
  • By control measures in vehicle emissions which are adequate.

Samacheer Kalvi 11th Chemistry Guide Chapter 15 Environmental Chemistry

11th Chemistry Guide Environmental Chemistry Additional Questions and Answers

I. Choose the best answer:

Question 1.
Which one of the following is a bio-degradable pollutant?
(a) DDT
(b) Plastics
(c) Mercury
(d) Wood
Answer:
(d) Wood

Question 2.
The greenhouse effect is caused by
(a) CO2
(b) NO2
(c) NO
(d) CO
Answer:
(a) CO2

Question 3.
Which of the following pair of oxides is responsible for acid rain?
(a) SO3 + NO2
(b) CO2 + CO
(c) N2O + CH4
(d) O2 + H2
Answer:
(a) SO3 + NO2

Question 4.
In Antarctica ozone depletion is due to the formation of the following compound
(a) acrolein
(b) peroxyacetyl nitrate
(c) SO2 and NO2
(d) chlorine nitrate
Answer:
(a) acrolein

Question 5.
Which of the following is not a greenhouse gas’?
(a) CO
(b) O3
(c) CH4
(d) Water vapours
Answer:
(a) CO

Samacheer Kalvi 11th Chemistry Guide Chapter 15 Environmental Chemistry

Question 6.
Classical smog occurs in places of
(a) excess SO2
(b) low temperature
(c) high temperature
(d) excess NH3
Answer:
(b) low temperature

Question 7.
Which gas is responsible for ‘Bhopal Gas Tragedy in 1984?
(a) CO
(b) Methyl isocynate
(c) SO2 and NO2
(d) Ethyl isocynate
Answer:
(b) Methyl isocynate

Question 8.
Which gas is a main reason behind air pollution, is produced by
(a) sewage pollutant
(b) aerosols
(c) industrial remains
(d) Above all
Answer:
(b) aerosols

Question 9.
Which is a dangerous radiological pollutant?
(a) C14
(b) S35
(c) Sr90
(d) P32
Answer:
(c) Sr90

Question 10.
Which is related to the ‘Green House Effect’?
(a) Farming of Green Plants
(b) Farming of Vegetables in Houses
(c) Global Warming
(d) Biodegradable pollutant
Answer:
(c) Global Warming

Samacheer Kalvi 11th Chemistry Guide Chapter 15 Environmental Chemistry

Question 11.
The uppermost region of the atmosphere is called
(a) Ionosphere
(b) Mesosphere
(c) Troposphere
(d) Stratosphere
Answer:
(d) Stratosphere

Question 12.
Which of the following is the coldest region of the atmosphere?
(a) Thermosphere
(b) Mesosphere
(c) Troposphere
(d) Stratosphere
Answer:
(b) Mesosphere

Question 13.
The region which is greatly affected by air pollution is
(a) Thermosphere
(b) Stratosphere
(c) Troposphere
(d) Mesosphere
Answer:
(c) Troposphere

Question 14.
The substance which is a primary pollutant?
(a) H2SO4
(b) CO
(c) PAN
(d) Aldehydes
Answer:
(b) CO

Question 15.
Depletion of ozone layer causes
(a) breast cancer
(b) blood cancer
(c) lung cancer
(d) skin cancer
Answer:
(d) skin cancer

Samacheer Kalvi 11th Chemistry Guide Chapter 15 Environmental Chemistry

Question 16.
Formation of London smog takes place in
(a) Winter during day time
(b) summer during day time
(c) summer during morning time
(d) winter during morning time
Answer:
(d) winter during morning time

Question 17.
The substance which is not regarded as a pollutant?
(a) NO2
(b) CO2
(c) O3
(d) Hydrocarbons
Answer:
(b) CO2

Question 18.
Green house gases
(a) allow shorter wavelength to enter earth’s atmosphere while doesn’t allow longer wavelength to leave the earth’s atmosphere.
(b) allow longer wavelength to enter earth atmosphere while doesn’t allow shorter wavelength to leave the surface.
(c) don’t have wavelength-specific character.
(d) she wavelength-specific behaviour near the earth while far from earth these have wavelength-independent behavior.
Answer:
(a) allow shorter wavelength to enter the earth’s atmosphere while doesn’t allow longer wavelength to leave the earth’s atmosphere.

Question 19.
Carbon monoxide (CO) is harmful to man because
(a) it forms carbolic acid
(b) it generates excess CO2
(c) it is carcinogenic
(d) it competes with O2 for haemoglobin
Answer:
(d) it competes with O2 for haemoglobin

Question 20.
Today the concentration of greenhouse gases is very high because of
(a) use of refrigerator
(b) increased combustion of oils and coal
(c) deforestation
(d) All of the above
Answer:
(d) All of the above

Samacheer Kalvi 11th Chemistry Guide Chapter 15 Environmental Chemistry

Question 21.
The quantity of CO2 in atmosphere is
(a) 3.34 %
(b) 6.5 %
(c) 0.034 %
(d) 0.34 %
Answer:
(c) 0.034 %

Question 22.
BOD of pond is connected with
(a) microbes & organic matter
(b) organic matter
(c) microbes
(d) None of these
Answer:
(a) microbes & organic matter

Question 23.
When rain is accompanied by a thunderstorm, the collected rain water will have a pH value
(a) slightly lower than that of rain water without thunderstorm
(b) slightly higher than that when the thunderstorm is not there
(c) uninfluenced by occurrence of thunderstorm
(d) which depends upon the amount of dust in air
Answer:
(a) slightly lower than that of rain water without thunderstorm

Question 24.
Water pollution is caused by
(a) pesticides
(b) SO2
(c) O2
(d) CO2
Answer:
(a) pesticides

Question 25.
Minamata disease of Japan is due to pollution of
(a) Aresenic
(b) Lead
(c) Cynide
(d) Mercury
Answer:
(d) Mercury

Samacheer Kalvi 11th Chemistry Guide Chapter 15 Environmental Chemistry

Question 26.
Which causes death of fish in water bodies polluted by sewage?
(a) Foul smell
(b) Pathogens
(c) Herbicides
(d) Decrease in D.O.
Answer:
(d) Decrease in D.O.

Question 27.
Sewage water is purified by
(a) aquatic plants
(b) microorganisms
(c) light
(d) fishes
Answer:
(b) microorganisms

Question 28.
Which pollutant is harmful for ‘Tajmahal’?
(a) Hydrogen
(b) O2
(c) SO2
(d) Chlorine
Answer:
(c) SO2

Question 29.
Negative soil pollution is
(a) reduction in soil productivity due to erosion and overuse
(b) reduction in soil productivity due to the addition of pesticides and industrial wastes
(c) converting fertile land into barren land by dumping ash, sludge, and garbage
(d) None of the above
Answer:
(a) reduction in soil productivity due to erosion and overuse

Question 30.
The quantity of DDT in the food chain
(a) decreases
(b) remains same
(c) increases
(d) changes
Answer:
(c) increases

Samacheer Kalvi 11th Chemistry Guide Chapter 15 Environmental Chemistry

Question 31.
Which is known as “Third poison of environment” and also creates ‘Blue baby syndrome’
(a) Nitrate present in water
(b) Phosphate and detergents found in water
(c) Cyanide
(d) Pesticides
Answer:
(b) Phosphate and detergents found in water

Question 32.
Is the substance having the largest concentration in acid rain?
(a) H2CO3
(b) HNO3
(c) HCl
(d) H2SO4
Answer:
(d) H2SO4

Question 33.
Water is often treated with chlorine to
(a) remove hardness
(b) increase oxygen content
(c) kill germs
(d) remove suspended particles
Answer:
(c) kill germs

Question 34.
Thermal pollution affects mainly
(a) vegetation
(b) aquatic creature
(c) rocks
(d) air
Answer:
(b) aquatic creature

Question 35.
B.O.D test or biochemical oxygen demand test is made for measuring
(a) air pollution
(b) water pollution
(c) noise pollution
(d) soil pollution
Answer:
(b) water pollution

Samacheer Kalvi 11th Chemistry Guide Chapter 15 Environmental Chemistry

Question 36.
Brewery and sugar factory water alters the quality of a water body by increasing
(a) temperature
(b) turbidity
(C) pH
(d) COD and BOD
Answer:
(d) COD and BOD

Question 37.
A dental disease characterized by mottling of teeth is due to the presence of a certain chemical element in drinking water. Which is that element?
(a) Boron
(b) Chlorine
(c) Fluorine
(d) Mercury
Answer:
(c) Fluorine

Question 38.
The high amount of E.coli in water is an indicator of
(a) hardness of water
(b) industrial pollution
(c) sewage pollution
(d) presence of chlorine in the water
Answer:
(c) sewage pollution

Question 39.
A lake with an inflow of domestic sewage rich in organic waste may result in
(a) drying of the lake very soon due to algal bloom
(b) an increased production of fish due to a lot of nutrients
(c) death of fish due to lack of oxygen
(d) increased population of aquatic food web organisms
Answer:
(c) death of fish due to lack of oxygen

Question 40.
In which one of the following the BOD (Biochemical Oxygen Demand) of sewage(S), distillery effluent (DE), paper mill effluent (PE) and sugar mill effluent (SE) have been arranged in ascending order
(a) SE < S < PE < DE
(b) SE < PE < S < DE
(c) PE < S < SE < DE
(d) S < DE < PE < SE
Answer:
(c) PE < S < SE < DE

Samacheer Kalvi 11th Chemistry Guide Chapter 15 Environmental Chemistry

Question 41.
The greenhouse effect is because of the
(a) presence of gases, which in general are strong infrared absorbers, in the atmosphere
(b) presence of CO2 only in the atmosphere
(c) presence of O3 and CH4 in the atmosphere
(d) N2O and chlorofluoro hydrocarbons in the atmosphere
Answer:
(a) presence of gases, which in general are strong infrared absorbers, in the atmosphere

Question 42.
Which of the following is/are the hazardous pollutant(s) present in automobile exhaust gases?
(a) N2
(b) CO
(c) CH4
(d) Oxides of nitrogen
Answer:
(c) CH4

Question 43.
Green chemistry means such reactions which:
(a) produce colour during reactions
(b) reduce the use and production of hazardous chemicals
(c) are related to the depletion of ozone layer
(d) study the reactions in plants
Answer:
(b) reduce the use and production of hazardous chemicals

Question 44.
Which one of the following statement is not true?
(a) pH of drinking water should be between 5.5 – 9.5.
(b) Concentration of DO below 6 ppm is good for the growth of fish.
(c) Clean water would have a BOD value of less than 5 ppm.
(d) Oxides of sulphur, nitrogen and carbon are the most widespread air pollutant.
Answer:
(b) Concentration of DO below 6 ppm is good for the growth of fish.

Question 45.
Which one of the following statements regarding photochemical smog is not correct?
(a) Carbon monoxide does not play any role in photochemical smog formation.
(b) photochemical smog is an oxidizing agent in character.
(c) photochemical smog is formed through a photochemical reaction involving solar energy.
(d) Photochemical smog does not cause irritation in eyes and throat.
Answer:
(d) Photochemical smog does not cause irritation in eyes and throat.

Samacheer Kalvi 11th Chemistry Guide Chapter 15 Environmental Chemistry

Question 46.
Frequent occurrence of water blooms in a lake indicates
(a) nutrient deficiency
(b) oxygen deficiency
(c) excessive nutrient availability
(d) absence of herbivores in the lake
Answer:
(b) oxygen deficiency

Question 47.
The smog is essentially caused by the presence of
(a) Oxides of sulphur and nitrogen
(b) O2 and N2
(c) O2 and O3
(d) O2 and N2
Answer:
(a) Oxides of sulphur and nitrogen

Question 48.
Identify the wrong statement in the following.
(a) Chlorofluorocarbons are responsible for ozone layer depletion.
(b) Greenhouse effect is responsible for global warming.
(c) Ozone layer does not permit infrared radiation from the sun to reach the earth.
(d) Acid rain is mostly because of oxides of nitrogen and sulphur.
Answer:
(c) Ozone layer does not permit infrared radiation from the sun to reach the earth.

Question 49.
Identify the incorrect statement from the following.
(a) Ozone absorbs the intense ultraviolet radiation of the sun.
(b) Depletion of ozone layer is because of its chemical reactions with chlorofluoro alkanes.
(c) Ozone absorbs infrared radiation.
(d) Oxides of nitrogen in the atmosphere can cause the depletion of ozone layer.
Answer:
(c) Ozone absorbs infrared radiation

Question 50.
What is DDT among the following?
(a) Greenhouse gas
(b) A fertilizer
(c) Biodegradable pollutant
(d) Non – biodegradable pollutant
Answer:
(d) Non – biodegradable pollutant

Samacheer Kalvi 11th Chemistry Guide Chapter 15 Environmental Chemistry

Question 51.
The gas leaked from a storage tank of the Union Carbide plant in Bhopal gas tragedy was:
(a) Methyl isocyanate
(b) Methylamine
(c) Ammonia
(d) Phosgene
Answer:
(a) Methyl isocyanate

Question 52.
Black – foot disease is caused due to groundwater contaminated with an excess of
(a) Nitrate
(b) Fluoride
(c) Arsenic
(d) Sulphur
Answer:
(c) Arsenic

Question 53.
Exposure of an organism to UV system causes
(a) photodynamic action
(b) formation of thymidine
(c) splitting of H – bonds of DNA
(d) splitting of phosphodiester bonds
Answer:
(c) splitting of H – bonds of DNA

Question 54.
Under column – I, a list of gases that are known to have a greenhouse effect is given. Relate them to their main source selecting from the given under Column – II:

Column – I Column – II
A. Nitrous oxide 1. Secondary pollutant from car exhausts
B. Chlorofluorocarbon (CFCs) 2. Combustion of fossil fuels, wood, etc.
C. Methane 3. Denitrification
D. Ozone (O3) 4. refrigerators, aerosol, sprays
E. Carbon dioxide 5. Cattle, rice fields, toilets

(a) A – 3, B – 4, C – 5, D – 1, E – 2
(b) A – 5, B – 1, C – 3, D – 4, E – 2
(c) A – 4, B – 5 , C – 1, D – 2, E – 3
(d) A – 1, B – 3, C – 4, D – 5, E – 2
Answer:
(a) A – 3, B – 4, C – 5, D – 1, E – 2

Question 55.
Minamata disease is a pollution-related disease results form
(a) oil spills into the sea
(b) accumulation of arsenic into the atmosphere
(c) release of industrial waste mercury into bodies of water
(d) release human organic waste into drinking water
Answer:
(c) release of industrial waste mercury into bodies of water

Samacheer Kalvi 11th Chemistry Guide Chapter 15 Environmental Chemistry

Question 56.
Air pollution causing photochemical oxidants production include
(a) Carbon monoxide, sulphur dioxide
(b) Nitrous oxide, nitric acid fumes, nitric oxide
(c) Ozone, peroxyacetyl nitrate, aldehydes
(d) Oxygen, chlorine, fuming nitric acid
Answer:
(c) Ozone, peroxyacetyl nitrate, aldehydes

Question 57.
Photochemical smog formed in congested metropolitan cities mainly consists of
(a) ozone, peroxyacetyl nitrate, and NOx
(b) smoke, peroxyacetyl nitrate and SO2
(c) hydrocarbons, SO2 and CO2
(d) hydrocarbons, ozone, and SOx
Answer:
(a) ozone, peroxyacetyl nitrate, and NOx

Question 58.
Which, one of the following statements is correct?
(a) Extensive use of chemical fertilizers may lead to eutrophication of nearby water bodies
(b) Both Azotobacter and Rhizobium fix atmospheric nitrogen in root nodules of plants
(c) Cyanobacteria such as Anabaena and Nostoc are important mobilizers of phosphates and potassium for plant nutrition in the soil
(d) At present it is not possible to grow maize without chemical fertilizers
Answer:
(a) Extensive use of chemical fertilizers may lead to eutrophication of nearby water bodies

Question 59.
Reducing the use of non-biodegradable things will contribute of
(a) Increase in O2
(b) Cyanophycean blooms occur
(c) Depletion of O2 layers
(d) Eutrophication
Answer:
(a) Increase in O2

Question 60.
Which of the following metal is a water pollutant and causes sterility in human. being?
(a) As
(b) Mn
(c) Mg
(d) Hg
Answer:
(b) Mn

Samacheer Kalvi 11th Chemistry Guide Chapter 15 Environmental Chemistry

Question 61.
Lichens do not like to grow in cities
(a) because of absence of the right type of algae and fungi
(b) because of lack of moisture
(c) because of SO2 pollution
(d) because natural habitat is missing
Answer:
(c) because of SO2 pollution

Question 62.
Limit of BOD prescribed by Central pollution Control Board for the discharge of industrial and municipal wastewaters into natural surface waters is
(a) < 100 ppm
(b) < 30 ppm
(c) < 3.0 ppm
(d) < 10 ppm
Answer:
(b) < 30 ppm

Question 63.
Which one of the following pairs is mismatched
(a) Fossil fuel burning – release of CO2
(b) Nuclear power – radioactive wastes
(c) Solar energy – The greenhouse effect
(d) Biomass burning – release of CO2
Answer:
(c) Solar energy – The greenhouse effect

Question 64.
In a coal-fired power plant, electrostatic precipitators are installed to control the emission of
(a) SO2
(b) NOx
(c) SPM
(d) CO
Answer:
(c) SPM

Question 65.
The term “Biomagnification” refers to the
(a) growth of organism due to food consumption
(b) increase in population size
(c) blowing up of environmental issues by man
(d) increase in the concentration of non-degradable pollutants as they pass through the food chain
Answer:
(d) increase in the concentration of non-degradable pollutants as they pass through the food chain

Samacheer Kalvi 11th Chemistry Guide Chapter 15 Environmental Chemistry

Question 66.
In almost all Indian metropolitan cities like Delhi, the major atmospheric pollutant(s) is/are
(a) suspended particulate matter (SPM)
(b) oxides of sulphur
(c) carbon dioxide and carbon monoxide
(d) oxides of nitrogen
Answer:
(a) suspended particulate matter (SPM)

Question 67.
In coming years, skin-related disorders will be more common due to
(a) pollutants in air
(b) use of detergents
(c) water pollution
(d) depletion of ozone layer
Answer:
(d) depletion of ozone layer

Question 68.
Statement 1:
Inhabitants close to very busy airports are likely to experience health hazards.
Statement 2:
Sound level of jet aeroplanes usually exceeds 160 dB.
(a) Statement – 1 is True, Statement – 2 is True, Statement – 2 is a correct explanation for Statement – 1.
(b) Statement – 1 is True, Statement – 2 is True, Statement – 2 is not a correct explanation for statement – 1
(c) Statement – 1 is True, Statement – 2 is False
(d) Statement – 1 is False, Statement – 2 is True
Answer:
(a) Statement – 1 is True, Statement – 2 is True, Statement – 2 is a correct explanation for Statement – 1.

Question 69.
Statement 1:
Suspended particulate matter (SPM) is an important pollutant released by diesel vehicles.
Statement 2:
Catalytic converters greatly reduce pollution caused by automobiles.
(a) Statement – 1 is True, Statement – 2 is True, Statement -2 is a correct explanation for Statement – 1.
(b) Statement – 1 is True, Statement – 2 is True, Statement – 2 is not a correct explanation for statement – 1
(c) Statement – 1 is True, Statement – 2 is False
(d) Statement – 1 is False, Statement – 2 is True
Answer:
(b) Statement – 1 is True, Statement – 2 is True, Statement – 2 is not a correct explanation for statement – 1

Question 70.
Statement 1:
Eutrophication shows increase in productivity in water.
Statement 2:
With increasing eutrophication, the diversity of the phytoplankton increases.
(a) Statement – 1 is True, Statement – 2 is True, Statement -2 is a correct explanation for Statement – 1.
(b) Statement – 1 is True, Statement – 2 is True, Statement – 2 is not a correct explanation for statement – 1
(c) Statement – 1 is True, Statement – 2 is False
(d) Statement – 1 is False, Statement – 2 is True
Answer:
(b) Statement – 1 is True, Statement – 2 is True, Statement – 2 is not a correct explanation for statement – 1

Samacheer Kalvi 11th Chemistry Guide Chapter 15 Environmental Chemistry

Question 71.
Statement 1:
The main cause of the Bhopal gas tragedy was phosgene.
Statement 2:
Phosgene is a volatile liquid.
(a) Statement – 1 is True, Statement – 2 is True, Statement -2 is a correct explanation for Statement – 1.
(b) Statement – 1 is True, Statement – 2 is True, Statement – 2 is not a correct explanation for statement – 1
(c) Statement – 1 is True, Statement – 2 is False
(d) Statement – 1 is False, Statement – 2 is True
Answer:
(d) Statement – 1 is False, Statement – 2 is True

Question 72.
Statement 1:
CO2 causes the greenhouse effect.
Statement 2:
Other gases do not show such an effect.
(a) Statement – 1 is True, Statement – 2 is True, Statement -2 is a correct explanation for Statement – 1
(b) Statement – 1 is True, Statement – 2 is True, Statement – 2 is not a correct explanation for statement – 1
(c) Statement – 1 is True, Statement – 2 is False
(d) Statement – 1 is False, Statement – 2 is True
Answer:
(c) Statement – 1 is True, Statement – 2 is False

Samacheer Kalvi 11th Chemistry Guide Chapter 15 Environmental Chemistry

II. Very short question and answers (2 Marks):

Question 1.
What is called environmental pollution?
Answer:
Any undesirable change in our environment that have harmful effects on plants. animals and human beings is called environmental pollution.

Question 2.
What are pollutants?
Answer:
The substances which cause pollution of the environment are called pollutants.

Question 3.
Write the different types of atmospheric pollution.
Answer:

  1. The lowest layer of the atmosphere is called the troposphere and il extends from 0 10 km from the earth surface.
  2. About 80% of the mass of the atmosphere is in this layer. 3 layers are present in it. They are
    • Hydrosphere
    • Lithosphere
    • Biosphere

Question 4.
What is Air pollution?
Answer:
Any undesirable change in the air which adversely affects living organisms is called air pollution. Air pollution is limited to the troposphere and stratosphere. Air pollution is mainly due to the excessive discharge of undesirable foreign matter into the atmospheric air.

Samacheer Kalvi 11th Chemistry Guide Chapter 15 Environmental Chemistry

Question 5.
What are the techniques adopted to reduce particulate pollutants?
Answer:
The particulates from the air can be removed by using electrostatic precipitators, gravity settling chambers, and wet scrubbers or by cyclone collectors. These techniques are based on washing away or settling of the particulates.

Question 6.
Define soil pollution.
Answer:
Soil pollution is defined as the buildup of persistent toxic compounds, radioactive materials, chemical salts, and disease-causing agents in soils which have harmful effects on plant growth and animal health.

Question 7.
Write the effects that were caused by classical smog.
Answer:

  1. Smog is primarily responsible for acid rain.
  2. The smog results in poor visibility and it affects air and road transport.
  3. It also causes bronchial irritation.

Samacheer Kalvi 11th Chemistry Guide Chapter 15 Environmental Chemistry

III. Short question and answers (3 Marks):

Question 1.
How the oxides of nitrogen pollute the atmospheric air?
Answer:
Oxides of nitrogen are produced during high temperature combustion processes, oxidation of nitrogen in air and from the combustion of fuels (coal, diesel, petrol etc.).
N2 + O2 Samacheer Kalvi 11th Chemistry Guide Chapter 15 Environmental Chemistry 8 2NO
2NO + O2 Samacheer Kalvi 11th Chemistry Guide Chapter 15 Environmental Chemistry 9 2NO2
NO + O3 → NO2 + O2

The oxides of nitrogen are converted into nitric acid which comes, down in the form of acid rain. They also form a reddish-brown haze in heavy traffic. Nitrogen dioxide potentially damages plant leaves and retards photosynthesis. NO2 is a respiratory irritant and it can cause asthma and lung injury. Nitrogen dioxide is also harmful to various textile fibres and metals.

Question 2.
How the hydrocarbon compounds make harmful effects on living things?
Answer:
The compounds composed of carbon and hydrogen only are called hydrocarbons. They are mainly produced naturally (marsh gas) and also by incomplete combustion of automobile fuel.

They are potential cancer-causing (carcinogenic) agents. For example, polynuclear aromatic hydrocarbons (PAH) are carcinogenic, they cause irritation in eyes and mucous membranes.

Question 3.
Explain the environmental impact of ozone depletion.
Answer:
The formation and destruction of ozone is a regular natural process, which never disturbs the equilibrium level of ozone in the stratosphere. Any change in the equilibrium level of the ozone in the atmosphere will adversely affect life in the biosphere in the following ways.

Depletion of ozone layer will allow more UV rays to reach the earth surface and layer would cause skin cancer and also decrease the immunity level in human beings. UV radiation affects plant proteins which leads to harmful mutation of cells. UV radiation affects the growth of phytoplankton, as a result ocean food chain is disturbed and even damages the fish productivity.

Samacheer Kalvi 11th Chemistry Guide Chapter 15 Environmental Chemistry

Question 4.
Write the causes of water pollution.
Answer:

  • The compounds composed of carbon and Hydrogen only are called hydrocarbons. They are mainly produced naturally and also by incomplete combustion of automobile fuels.
  • They are potential cancer-causing (carcinogenic) agents.
  • For example, polynuclear aromatic hydrocarbons (PAH) are carcinogenic, they cause irritation in eyes and mucous membranes.

Question 5.
(a) Define eutrophication and pneumoconiosis.
(b) Write differences between photochemical smog and classical smog.
Answer:
(a) Eutrophication:
When the growth of algae increases in the surface of the water, dissolved oxygen in water is greatly reduced. This phenomenon is known as eutrophication. Due to this growth of fishes gets inhibited.

(b) Pueumoconiosis:
It is a disease that irritates the lungs. It causes scarring or fibrosis of the lungs.

Photochemical smog:

  • It is formed as a result of the photochemical decomposition of nitrogen dioxide and chemical reactions involving hydrocarbons.
  • It takes place during the dry warm season in presence of sunlight.
  • It is oxidizing in nature.

Classical smog:

  • It’s formed due to the condensation of SO2 vapours on particles of carbon in cold climates.
  • it is generally formed during winter when there is severe cold.
  • It is reducing in nature.

Question 6.
Write the harmful effects caused by chemical water pollutants.
Answer:

  1. Cadmium and mercury can cause kidney damage.
  2. Lead poisoning can lead to severe damage of kidneys, liver, brain, etc. it also affects the central nervous system
  3. Polychlorinated biphenyls (PCBs) cause skin diseases and are carcinogenic in nature.

Samacheer Kalvi 11th Chemistry Guide Chapter 15 Environmental Chemistry

Question 7.
Distinguish between BOD and COD.
Answer:

BOD COD
1. BOD is the amount of oxygen required for the biological decomposition of organic matter present in the water. COD is the amount of oxygen required for chemical oxidation of organic matter using some oxidizing agent like K2Cr207 and KMn04.
2. It is an important indication of the amount of organic matter present in the river water. It is carried out to determine the pollution strength of river water.
3. Since complete oxidation occurs in an indefinite period, the reaction period is taken as 5 days at 20°C. It is a rapid process and takes only 8 hours.

IV. Long question and answer (5 Marks):

Question 1.
Explain the different layers of the earth’s atmosphere.
Answer:
Troposphere:
The lowest layer of the atmosphere is called the troposphere and it extends from o – 10 km from the earth’s surface. About 80% of the mass of the atmosphere is in this layer. This troposphere is further divided as follows.

i) Hydrosphere:
The hydrosphere includes all types of water sources like oceans, seas, rivers, lakes, streams, underground water, polar icecaps, clouds etc. It covers about 75% of the earth’s surface. Hence the earth is called a blue planet.

ii) Lithosphere:
The lithosphere includes soil, rocks and mountains which are solid components of earth.

iii) Biosphere:
It includes the lithosphere, hydrosphere, and atmosphere integrating the living organism present in the lithosphere, hydrosphere and atmosphere.

Question 2.
How the oxides of sulphur pollute the atmospheric air?
Answer:
Sulphur dioxide and sulphur trioxide are produced by burning sulfur-containing fossil fuels arid roasting sulphide ores. Sulphur dioxide is a poisonous gas to both animals and plants. Sulphur dioxide causes eye irritation, coughing and respiratory asthma, bronchitis, etc.

Sulphur dioxide is oxidised into more harmful sulphur trioxide in the presence of particulate matter present in polluted air.
2SO2 + O2 Samacheer Kalvi 11th Chemistry Guide Chapter 15 Environmental Chemistry 10 2SO3

SO3 combines with atmospheric water vapour to form H2SO4, which comes down in the form of acid rain.
SO3 + H2O → H2SO4

Question 3.
Explain the health effects of particulate pollutants for human health.
Answer:

  1. Dust, mist, fumes,etc., are air-borne particles which are dangerous for human health. Particulate pollutants bigger than 5 microns are likely to settle in the nasal passage whereas particles of about 10 micron enters the lungs easily and causes scarring or fibrosis of lung lining.
  2. They irritate the lungs and causes cancer and a,sthma. This disease is also called pneumoconiosis. Coal miners may suffer from black lung disease. Textile workers may suffer from white lung disease.
  3. Lead particulates affect children’s brain, interferes maturation of RBCs and even cause cancer.
  4. Particulates in the atmosphere reduce visibility by scattering and absorption of sunlight. It is dangerous for aircraft and motor vehicles
  5. Particulates provide nuclei for cloud formation and increase fog and rain.
  6. Particulates deposit on plant leaves and hinder the intake of CO2 from the air and affect photosynthesis.

Samacheer Kalvi 11th Chemistry Guide Chapter 15 Environmental Chemistry

Question 4.
Explain the effects of photochemical smog and its control.
Answer:
The three main components of photochemical smog are nitrogen oxide, ozone and oxidised hydrocarbon like formaldehyde(HCHO), Acrolein (CH2 = CH – CHO), peroxyacetyl nitrate (PAN). Photochemical smog causes irritation to eyes, skin and lungs, increase in chances of asthma.

High concentrations of ozone and NO can cause nose and throat irritation, chest pain, uncomfortable in breathing, etc. PAN is toxic to plants, attacks younger leaves and cause bronzing and glazing of their surfaces. It causes corrosion of metals stones, building materials and painted surfaces.

Control of Photochemical smog:
The formation of photochemical smog can be suppressed by preventing the release of nitrogen oxides and hydrocarbons into the atmosphere from motor vehicles by using catalytic convertors in engines. Plantation of certain trees like Pinus, Pyrus, Quercus Vitus, and Juniperus can metabolise nitrogen oxide.

Question 5.
List out the major water pollutants and their sources.
Answer:

Pollutant Sources
1.Microorganisms Domestic sewage, domestic wastewater, dung heap.
2. Organic wastes Domestic sewage, animal excreta, food processing factory waste, detergents, and decayed animals and plants.
3. Plant nutrients Chemical fertilizers.
4. Heavy metals Heavy metal producing factories.
5. Sediments Soil erosion by agriculture and strip-mining.
6. Pesticides Chemicals used for killing insects, fungi, and weeds.
7. Radioactive Mining of uranium-containing minerals substances.
8. Heat Water used for cooling in industries.

Question 6.
Describe the causes of water pollution.
Answer:
Causes of water pollution –
1. Microbiological pollutants:
(a) Disease causing microorganisms like bacteria, viruses and protozoa are most senous water pollutants. They come from domestic sewage and animal excreta.
(b) Fish and shellfish can become contaminated from them and people who eat them will also become ill.
(c) Dysentery and cholera are water borne diseases.
(d) Human excrcta contain bacteria such as Escherichia coll and Streptococcus farcical- -is which causes gastrointestinal diseases.

2. Organic wastes:
Organic matter such as leaves, grass, trash can also pollute water. Water pollution is cause by excessive phytoplankton growth within water.

3. Chemical wastes:
A whole variety of chemicals from industries such as metals and solvents are poisonous to fish and other aquatic life. Detergents and oils float spoils the water bodies. Acids from mine drainage and salts form various sources can also contaminate water sources.

Samacheer Kalvi 11th Chemistry Guide Chapter 15 Environmental Chemistry

Question 7.
Explain the various contribution of green chemistry in our day-to-day life.
Answer:
(1) Dry cleaning of clothes:
Solvents like tetrachloroethylene used in dry cleaning of clothes, pollute the groundwater and are carcinogenic. In the place of tetrachloroethylene, liquefied CO2 with suitable detergent is an Alternate solvent used. Liquified CO2 is not harmful to the groundwater. Now a days H2O2 used for bleaching clothes in laundry gives better results and utilizes less water.

(2) Bleaching of paper:
The conventional method of bleaching was done with chlorine. Nowadays H2O2 can be used for bleaching paper in presence of a catalyst.

(3) Synthesis of chemicals:
Acetaldehyde is now commercially prepared by one-step oxidation of ethene in the presence of anionic catalyst in an aqueous medium with a 90% yield.

CH2 = CH2 + O Samacheer Kalvi 11th Chemistry Guide Chapter 15 Environmental Chemistry 11 CH3CHO
Ethylene Acetaldehyde

(4) Instead of petrol, methanol is used as a fuel in automobiles:
Methanol is considered to be less expensive than other commercial fuel and gasoline. During the process of combustion, it provides a higher thermal efficiency and power output because of its high octane rating and high heat vaporization.

(5) Neem based pesticides have been synthesised, which are safer than the chlorinated hydrocarbons:
Every individual has an important role in preventing pollution and improving our environment. We Eire responsible for environmental protection. Let us begin to save our environment and provide clean earth for our future generations.

Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes

Tamilnadu State Board New Syllabus Samacheer Kalvi 11th Chemistry Guide Pdf Chapter 14 Haloalkanes and Haloarenes Text Book Back Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 11th Chemistry Solutions Chapter 14 Haloalkanes and Haloarenes

11th Chemistry Guide Haloalkanes and Haloarenes Text Book Back Questions and Answers

Textbook Evaluation:

I. Choose the best answer:

Question 1.
The IUPAC name of Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 1 is
a) 2 – Bromo pent – 3 – ene
b) 4 – Bromo pent – 2 – ene
c) 2 – Bromo pent – 4 – ene
d) 4 – Bromo pent – 1 – ene
Answer:
b) 4 – Bromo pent – 2 – ene

Question 2.
Of the following compounds, which has the highest boiling point?
a) n – Butyl chloride
b) Isobutyl chloride
c) t – Butyl chloride
d) n – Propyl chloride
Answer:
a) n – Butyl chloride

Question 3.
Arrange the following compounds in increasing order of their density
A) CCl4
B) CHCl3
C) CH2Cl2
D) CH3Cl
a) D < C < B < A
b) C > B > A > D
c) A < B < C < D
d) C > A > B > D
Answer:
a) D < C < B < A

Question 4.
With respect to the position of – Cl in the compound CH3 – CH = CH – CH2 – Cl, it is classified as
a) Vinyl
b) Allyl
c) Secondary
d) Aralkyl
Answer:
b) Allyl

Question 5.
What should be the correct IUPAC name of diethyl chloromethane?
a) 3 – Chloro pentane
b) 1 – Chloropentane
c) 1 – Chloro – 1, 1 – diethyl methane
d) 1- Chloro-1-ethyl propane
Answer:
a) 3 – Chloro pentane

Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes

Question 6.
C – X bond is strongest in
a) Chloromethane
b) Iodomethane
c) Bromomethane
d) Fluoromethane
Answer:
d) Fluoromethane

Question 7.
In the reaction Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 2 X is ______.

Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 3
Answer:
b) Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 4

Question 8.
Which of the following compounds will give racemic mixture on nucleophilic substitution by OH ion?
i) Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 5

ii) Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 6

iii) Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 7
a) (i)
b) (ii) and (iii)
c) (iii)
d) (i) and (ii)
Answer:
c) (iii)

Question 9.
The treatment of ethyl formate with excess of RMgX gives
a) Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 8

b) Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 9
c) R – CHO
d) R – O – R
Answer:
c) R – CHO

Question 10.
Benzene reacts with Cl2 in the presence of FeCl3 and in absence of sunlight to form
a) Chlorobenzene
b) Benzyl chloride
c) Benzal chloride
d) Benzene hexachloride
Answer:
a) Chlorobenzene

Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes

Question 11.
The name of C2F4C12 is
a) Freon – 112
b) Freon – 113
c) Freon – 114
d) Freon – 115
Answer:
c) Freon – 114

Question 12.
Which of the following reagent is helpful to differentiate ethylene dichloride and ehtylidene chloride?
a) Zn / methanol
b) KQH / ethanol
c) aqueous KOH
d) ZnCl2 / Con HCl
Answer:
c) aqueous KOH

Question 13.
Match the compounds given in Column I with suitable items given in Column II:

Column I (Compound) Column II (Uses)
A. Iodoform 1. Fire extinguisher
B. Carbon tetra chloride 2. Insecticide
C. CFC 3. Antiseptic
D. DDT 4. Refrigerants

Code
a) A → 2 B → 4 C → 1 D → 3
b) A → 3 B → 2 C → 4 D → 1
c) A → 1 B → 2 C → 3 D → 4
d) A → 3 B → 1 C → 4 D → 2
Answer:
d) A → 3 B → 1 C → 4 D → 2

Question 14.
Assertion:
Inmonohaloarenes, electrophilic substitution occurs at ortho and para positions.
Reason:
Halogen atom is a ring deactivator.
Assertion and Reason type questions.
Directions:
In the following questions, a statement of assertion (A) is followed by a statement of reason (R) mark the correct choice as
(i) If both assertion and reason are true and reason is the correct explanation of assertion.
(ii) If both assertion and reason are true but reason is not the correct explanation of assertion.
(iii) If assertion is true but reason is false.
(iv) If both assertion and reason are false.
a) (i)
b) (ii)
c) (iii)
d) (iv)
Answer:
b) (ii)

Question 15.
Consider the reaction,
CH3CH2CH2Br + NaCN → CH3CH2CH2CN + NaBr This reaction will be the fastest in
a) ethanol
b) methanol
c) DMF (N, N’ – dimethyl formamide)
d) water
Answer:
c) DMF (N, N’ – dimethyl formamide)

Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes

Question 16.
Freon – 12 manufactured from tetrachloro methane by
a) Wurtz reaction
b) Swarts reaction
c) Haloform reaction
d) Gattermann reaction
Answer:
b) Swarts reaction

Question 17.
The most easily hydrolysed molecules under SN1 condition is
a) allyl chloride
b) ethyl chloride
c) isopropyl chloride
d) benzyl chloride
Answer:
a) allyl chloride

Question 18.
The carbon cation formed in SN1 reaction of alkyl halide in the slow step is
a) sp3 hybridized
b) sp2 hybridized
c) sp hybridized
d) none of these
Answer:
b) sp2 hybridized

Question 19.
The major products obtained when chlorobenzene is nitrated with HNO3 and con H2SO4
a) 1 – chloro – 4 – nitrobenzene
b) 1 – chloro – 2 – nitrobenzene
c) 1 – chloro – 3 – nitrobenzene
d) 1 – chloro – 1 – nitrobenzene
Answer:
a) 1 – chloro – 4 – nitrobenzene

Question 20.
Which one of the following is most reactive towards nucleophilic substitution reaction?
a) Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 10

b) Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 11

c) Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 12

d) Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 13
Answer:
d) Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 13

Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes

Question 21.
Ethylidene chloride on treatment with aqueous KOH gives
a) acetaldehyde
b) ethylene glycol
c) formaldehyde
d) glycoxal
Answer:
a) acetaldehyde

Question 22.
The raw material for Raschig process
a) chloro benzene
b) phenol
c) benzene
d) anisole
Answer:
c) benzene

Question 23.
Chloroform reacts with nitric acid to produce
a) nitro toluene
b) nitro glycerine
c) chloropicrin
d) chloropicric acid
Answer:
c) chloropicrin

Question 24.
Acetone Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 14 X, X is
a) 2 – propanol
b) 2 – methyl – 2 – propanol
c) 1 – propanol
d) acetonol
Answer:
b) 2 – methyl – 2 – propanol

Question 25.
Silverpropionate when refluxed with Bromine in carbon tetrachloride gives
a) propionic acid
b) chloroethane
c) Bromo ethane
d) chloro propane
Answer:
c) bromo ethane

Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes

II. Write brief answer to the following questions:

Question 26.
Classify the following compounds in the form of alkyl, allylic, vinyl, benzylic halides.
i) CH3 – CH = CH – Cl

ii) C6H5CH2I

iii) Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 15

iv) CH2 = CH – Cl
Answer:
i) CH3 – CH = CH – Cl = Allylic halide

ii) C6H5CH2I = Benzylic halide

iii) Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 15 = Alkyl halide

iv) CH2 = CH – Cl = Vinyl halide

Question 27.
Why chlorination of methane is not possible in dark?
Answer:

  • Chlorination of methane is a free radical substitution reaction.
  • Before chlorine reacts with methane, the Cl-Cl single bond must break to form free radicals and this can only be done in the presence of ultraviolet light.
  • In dark, chlorine-free radicals formation is not possible and so chlorination of methane is not possible in dark.
  • The ultraviolet light is a source of energy and is being used to break of Cl-Cl and produce Cl free radical Free radicals which can attack methane. in dark, this is not possible.

Question 28.
How will you prepare n propyl iodide from n – propyl bromide?
Answer:
Finkelstein reaction,
nCH3 – CH2 – CH2 – Br + NaI Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 16 n – CH3 – CH2 – CH2 – I + NaBr
n – propyl iodide                                              n- propyl bromide

Question 29.
Which alkyl halide from the following pair is
i) chiral
ii) undergoes faster SN2 reaction?
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 17
Answer:
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 18
It contains one chiral carbon atom.
2 – Bromo butane undergoes SN2 mechanism faster than 1- Chloro butane.

Question 30.
How does chlorobenzene react with sodium in the presence of ether? What is the name of the reaction?
Answer:
Haloarenes react with sodium metal in dry ether, two aryl groups combine to give biaryl products.
This reaction is called fittig reaction.
C6H5Cl + 2Na + Cl – C6H5 Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 19 C6H5 – C6H5 + 2NaCl
Chlorobenzene                                      Biphenyl

Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes

Question 31.
Give reasons for the polarity of C – X bond in haloalkane.
Answer:
Carbon halogen bond is a polar bond as halogens are more electronegative than carbon. The carbon atom exhibits a partial positive charge (δ+) and halogen atom a partial negative charge (δ)
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 20

The C -X bond is formed by overlap of sp3 orbital of a carbon atom with half-filled p- orbital of the halogen atom. The atomic size of halogen increases from fluorine to iodine, which increases the C – X bond length. Larger the size, greater is the bond length, and the weaker is the bond formed. The bond strength of C – X decreases from C – F to C – I in CH3X.

Question 32.
Why is it necessary to avoid even traces of moisture during the use of Grignard reagent?
Answer:
Grignard reagents are mostly reactive and react with the source of the product to give hydrocarbons. Even alcohols, amines, H2O are sufficiently acidic to convert them to corresponding hydrocarbons.
R Mg X + H2O → RH + Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 21

Due to its high reactivity, it is necessary to avoid even traces of moisture from the Grignard reagent.

Question 33.
What happens when acetyl chloride is treated with an excess of CH3MgI?
Answer:
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 22

Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 23

Question 34.
Arrange the following alkyl halide in increasing order of bond enthalpy of RX.
CH3Br, CH3F, CH3Cl, CH3I
Answer:
The order is:
CH3I < CH3Br < CH3Cl < CH3F.

Question 35.
What happens when chloroform reacts with oxygen in the presence of sunlight?
Answer:
2 CHCl3 + O2 → 2 COCl2 + 2 HCl

Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes

Question 36.
Write down the possible isomers of C5H11Br and give their IUPAC and common names.
Answer:
C5H11Br – Possible isomers
1. CH3 – CH2 – CH2 – CH2 – CH2 – Br → 1 – bromo pentane

2. Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 24 → 2 – bromo pentane

3. Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 25 → 3 – bromo pentane

4.  Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 26 → 1 – bromo 2, 2 – dimethyl propane

5. Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 27 → 1 – bromo 3 – methyl butane

6. Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 28 → 2 – bromo 3 – methyl butane

7. Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 29 → 2 – bromo 2 – methyl butane

8. Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 30 → 1 – bromo 2- methyl butane

9. Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 31 → (2S) – 1 – bromo 2 – methyl butane

10. Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 32 → (2R) – 1 – bromo 2 – methyl butane

Question 37.
Mention any three methods of preparation of haloalkanes from alcohols.
Answer:
Haloalkanes are prepared by the following methods.
From alcohols: Alcohol can be converted into halo alkenes by reacting it with any one of the following reagents.

  • Hydrogen halide
  • Phosphorous halides
  • Thionyl chloride.

a) Reaction with hydrogen halide:
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 33

Mixture of con. HCl and anhydrous ZnCl2 is called Lucas Reagent.

Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 34

The order of reactivity of halo acids with alcohol is in the order HI > HBr > HCl.
The order of reactivity of alcohols with halo acid is tertiary > secondary > primary.

b) Reaction with phosphorous halides:
Alcohols react with PX5 or PX3 to form haloalkanes.
Example:
CH3CH2OH + PCl5 → CH3CH2Cl + POCl3 + HCl
Ethane                      Chloro ethane

3CH3CH2OH + PCl3 → 3 CH3CH2Cl + H3PO3
Ethanol                       Chloro ethane

c) Reaction with Thionyl chloride(Sulphonyl Chloride)
CH3CH3OH + SOCl2 Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 35 CH3CH2Cl + SO2↑ + HCl↑
Ethanol                                      Chloro ethane

Question 38.
Compare SN1 and SN2 reaction mechanisms.
Answer:

SN1 SN2
Rate law Unimolecular (Substrate only) Biomolecular (substrate and nucleophile)
“Big Barrier” Carbocation stability Steric hindrance
Alkyl halide (electrophile) 3° > 2° > 1°  1° > 2° > 3°
Nucleophile Weak (generally neutral) Strong (generally bearing a negative charge)
Solvent Polar protic (e.g., alcohols) Polar aprotic (e.g., DMSO, acetone)
Stereo Chemistry Mix of retention and inversion inversion

Question 39.
Reagents and the conditions used in the reactions are given below. Complete the table by writing down the product and the name of the reaction.
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 36
Answer:
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 37

Question 40.
Discuss the aromatic nucleophilic substitutions reaction of chlorobenzene.
Answer:
The halogen of haloarenes can be substituted by OH, NH2 or CN with appropriate nucleophilic reagents at high temperature and pressure.
Example:
(i) Chlorobenzene reacts with ammonium at 250 and at 50 atm to give aniline.
C6H5Cl + 2NH3 Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 38 C6H5NH2 + NH4Cl
Chlorobenzene                  Aniline

(ii) Chlorobenzcne reacts with CuCN in presence of pyridine at 250 to give phenyl cyanide.
C6H5Cl + CuCN Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 39 C6H5CN + CuCl
Chlorobenzene                Phenyl cyanide

(iii) Dows process:
C6H5Cl + NaOH Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 40 C6H5OH + NaCl
Chlorobenzene                   Phenol
This reaction is known as Dow’s process.

Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes

Question 41.
Account for the following:
(i) t – butyl chloride reacts with aqueous KOH by SN1 mechanism while n – butyl chloride reacts with SN2 mechanism.
(ii) p – dichlorobenzene has a higher melting point than those of o – and m – dichlorobenzene.
Answer:
(i) t – butyl chloride reacts with aqueous KOH by SN1 mechanism while n – butyl chloride reacts with SN2 mechanism.
In general, the SN1 reaction proceeds through the formation, of carbocation, The tert-butyl chloride readily loses Cl ion to form stable 3° carbocation. Therefore, it reacts with aqueous KOH by SN1 mechanism as:
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 41

On the other hand, n-Butyl chloride does not undergo ionization to form n-Butyl carbocation (1°) because it is not stable. Therefore, it prefers to undergo reaction by an SN2 mechanism, which occurs is one step through a transition state involving the nucleophilic attack of OH ion from the backside with simultaneous expulsion of Cl ion from the front side.
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 42

SN1 mechanism follows the reactivity order as 3° > 2°> 1° while SN2 mechanism follows the reactivity order as 1° > 2° > 3°. Therefore, tert-butyl chloride (3°) reacts by SN1 mechanism while n-butyl chloride (1°) reacts by an SN2 mechanism. (ii) p – dichlorobenzene has a higher melting point than those of o – and m – dichloro benzene. The higher melting point of p – isomer is due to its symmetry which leads to more close packing of its molecules in the crystal lattice and consequently strong intermolecular attractive force which requires more energy for melting. p – Dihalo benzene > o – Dichloro benzene> m – Dichioro benzene
Melting point: 323 K 256 K 249 K

Question 42.
In an experiment methyl iodide in ether is allowed to stand over magnesium pieces. Magnesium dissolves and product is formed.
a) Name of the product and write the equation for the reaction.
b) Why all the reagents used in the reaction should be dry? Explain.
c) How is acetone prepared from the product obtained in the experiment?
Answer:
a) Name of the product and write the equation for the reaction.
CH3I + Mg Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 43 CH3MgI

b) Why all the reagents used in the reaction should be dry? Explain.
All the reagents used in the reaction should be dry because reagent reacts with H20 to produce alkane. This is the reason that everything has to be very dry during the preparation of Grignard reagents.
CH3 – MgI + H2O → CH4 +Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 44
Methane

c) How is acetone prepared from the product obtained in the experiment?
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 45

Question 43.
Write a chemical reaction useful to prepare the following.
i) Freon – 12 from Carbon tetrachloride
ii) Carbon tetrachloride from carbon disulphide.
Answer:
i) Freon – 12 from Carbon tetrachloride:
Freon – 12 is prepared by the action of hydrogen fluoride on carbon tetrachloride in the presence of catalytic amount of antimony pentachloride.
CCl4 + 2HF Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 46 2HCl + CCl2F2
Carbon tetrachloride            Freon – 12

ii) Carbon tetrachloride from carbon disulphide.
Carbon disulphide reacts with chlorine gas in the presence of anhydrous AlCl3 as catalyst giving carbon tetrachloride.
CS2 + 3 Cl2 Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 47 CCl4 + S2Cl2
Carbon disulfide                Carbon tetrachloride

Question 44.
What are Freons? Discuss their uses and environmental effects.
Answer:
The chloro fluoro derivatives of methane and ethane are called freons.
Nomenclature:
Freon is represented as Freon – cba
Where a = number of carbon atoms – 1;
b = number of hydrogen atoms + 1
a = total number of fluorine atoms
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 48

Uses:

  • Freons are used as a refrigerant in refrigerators and air conditioners.
  • It is used as a propellant for aerosols and foams
  • It is used as a propellant for foams to spray out deodorants, shaving creams, and insecticides.

Question 45.
Predict the products when Bromo ethane is treated with the following.
i) KNO2
ii) AgNO2
Answer:
i) KNO2:
Bromo ethane reacts with an alcoholic solution of NaNO2 or KNO2 to form ethyl nitrite.
CH3CH2Br + KNO2 → CH3CH2 – O – N = O + KBr
Bromoethane Ethyl nitrite

ii)AgNO2:
Bromo ethane reacts with an alcoholic solution of AgNO2 to form nitroethane.
CH3CH2Br + AgNO2 → CH3CH2 NO2 + AgBr
Bromoethane                Nitroethane

Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes

Question 46.
Explain the mechanism of SN1 reaction by highlighting the stereochemistry behind it.
Answer:
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 49
In SN1 reactions, if the alkyl halide is optically active, the product obtained in a racemic mixture. The intermolecular carbocation formed in slowest step being sp2 hybridized is planar species. Therefore the attack of the nucleophile OH on it, can occur from both the faces with equal case forming a mixture of two enantiomers. Thus SN1 reaction of optically active alkyl halides is accompanied by racemization.

Question 47.
Write short notes on the following.
i) Raschig process
ii) Dows process
iii) Darzen’s process
Answer:
i) Raschig process:
Chloro benzene is commercially prepared by passing a mixture of benzene vapour, air and HCl overheated cupric chloride, this reaction is called the Raschig process,
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 50

ii) Dows Process:
C6H5Cl + NaOH Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 51 C6H5OH + NaCl
This reaction is known as Dows process.

iii) Darzen’s process:
CH3CH2OH + SOCl Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 51 CH3CH2Cl + SO2↑ + HCl↑
Ethanol Chloro ethane
This reaction is known as Darzen’s process.

Question 48.
Starting from CH3MgI, How will you prepare the following?
i) Acetic acid
ii) Acetone
iii) Ethyl acetate
iv) Isopropyl alcohol
v) Methyl cyanide
Answer:
i) Acetic acid:
Solid carbon dioxide reacts with methyl magnesium iodide to form additional product which on hydrolysis yields acetic acid.
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 52

ii) Acetone:
Acetyl chloride reacts with methyl magnesium iodide and followed by acid hydrolysis to give acetone.
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 53

iii) Ethyl Acetate:
Ethyl chloroformate reacts with methyl magnesium iodide to form ethyl acetate.
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 54

iv) Isopropyl alcohol:
Aldehydes (Acetaldehyde) other than formaldehyde, react with methyl magnesium iodide to give additional product which on hydrolysis yields isopropyl alcohol.
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 55

v) Methyl cyanide:
Methyl magnesium iodide reacts with cyanogen chloride to give methyl cyanide.
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 56

Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes

Question 49.
Complete the following reactions.
i) CH3 – CH = CH2 + HBr Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 57
ii) CH3 – CH2 – Br + NaSH Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 58
iii) C6H5Cl + Mg Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 59
iv) CHCl3 + HNO3 Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 60
v) CCl4 + H2O Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 60
Answer :
i) CH3 – CH = CH2 + HBr Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 57 CH3 – CH2 – CH2 – Br
Propene                                                   n – propyl bromide

ii) CH3 – CH2 – Br + NaSH Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 58 CH3 – CH2 – SH + NaBr
Propyl bromide                                     Ethanethiol

iii) C6H5Cl (Chloro benzene) + Mg Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 59 C6H5MgCl (Phenyl magnesium chloride)

iv) CHCl3 + HNO3 Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 60 CCl3NO2 + H
Chloroform                               Chloropicrin

v) CCl4 (Carbon tetrachloride) + H2O Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 60COCl2 (Carbonyl chloride) + 2HCl

Question 50.
Explain the preparation of the following compounds.
i) DDT
ii) Chloroform
iii) Biphrnyl
iv) Chloropicrin
v) Freon – 12
Answer:
i) DDT:
DDT can be prepared by heating a mixture of chlorobenzene with chloral (Trichloro acetaldehyde) in the presence of con.H2SO4.
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 61

ii) Chloroform:
Preparation:
Chloroform is prepared in the laboratory by the reaction between ethyl alcohol with bleaching powder followed by the distillation of the product chloroform. Bleaching powder act as a source of chlorine and calcium hydroxide. This reaction is called the haloform reaction. The reaction proceeds in three steps as shown below.

Step – 1: Oxidation
CH3CH2OH + Cl2 → CH3CHO + 2HCl
Ethyl alcohol           Ethanal (Acetaldehyde)

Step – 2: Chlorination
CH3CHO + 3Cl2 → CCl3CHO + 3HCl
Acetaldehyde        Trichloro acetaldehyde

Step – 3: Hydrolysis
2CCl3CHO + Ca(OH)2 → 2CHCl3 + (HCOO)2 Ca
Chloral                         chloroform

iii) Biphenyl:
Chloro benzene reacts with sodium metal in dry ether, to give biphenyl. This reaction is called a fitting reaction.
C6H5Cl + 2 Na + Cl – C6H5 Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 65 C6H5 – C6H5 + 2NaCl
Chloro benzene                                          Biphenyl

iv) Chloropicrin:
Chloroform reacts with nitric acid to form chloropicrin. (Trichloro nitromethane)
CHCl3 + HNO3 Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 66 CCl3NO2 + H2O
Chloroform                   Chloropicrin

v) Freon – 12
Freon – 12 is prepared by the action of hydrogen fluoride on carbon tetrachloride in the presence of the catalytic amount of antimony pentachloride
CCl4 + 2 HF Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 67 2 HCl + CCl2F2
Carbon tetrachloride                     Freon – 12

Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes

Question 51.
An organic compound (A) with molecular formula C2H5Cl reacts with KOH gives compounds (B) and with alcoholic KOH gives compound (C). Identify (A), (B), (C).
Answer:
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 62

Question 52.
The simplest alkene (A) reacts with HCl to form compound (B). Compound (B) reacts with ammonia to form compound (C) of molecular formula C2H7N. Compound (C) undergoes carbylamine test. Identify (A),
(B) and (C).
Answer:
CH2 = CH2 + HCl → C2H5Cl
(A) Ethylene              (B) Ethyl chloride

C2H5Cl + NH3    →    C2H5NH2 + HCl
(C) Ethyl chloride      (B) Ethyl amine

Question 53.
A hydrocarbon C3H6(A) reacts with HBr to form compound (B). Compound (B) reacts with aqueous potassium hydroxide to give (C) of molecular formula C3H6O. What are the (A), (B) and (C). Explain the reactions.
Answer:
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 63

Question 54.
Two isomers (A) and (B) have the same molecular formula C2H4Cl2. Compound (A) reacts with aqueous KOH gives compound (C) of molecular formula C2H4O. Compound (B) reacts with aqueous KOH gives compound (D) of molecular formula C2H6O2. Identify (A), (B), (C) and (D).
Answer:
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 64

Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes

11th Chemistry Guide Haloalkanes and Haloarenes Additional Questions and Answers

I. Choose the best answer:

Question 1.
Which of the following is an example of polyhalo compounds?
(a) Vnyl iodide
(b) Chiorobenzene
(c) Allyl chloride
(d) Chloroform
Answer:
(d) Chloroform

Question 2.
2° halide among the following
a) isopropyl chloride
b) isobutyl chloride
c) n – propyl chloride
d) n – butyl chloride
Answer:
a) isopropyl chloride

Question 3.
How many isomers are possible for the formula C4H9Cl?
(a) 3
(b) 2
(c) 4
(d) 5
Answer:
(c) 4

Question 4.
Which of the following is gemdihalide?
a) CH3CHBrCH2Br
b) CH3CHBr2
c) CH3CHBrCH2CH2Br
d) BrCH2CH2Br
Answer:
b) CH3CHBr2

Question 5.
Which of the following is called Lucas reagent?
(a) Conc. H2SO4 + Anhydrous CuSO4
(b) Conc.HCl + Anhydrous ZnCl2
(c) Dil.HCl + AlCl3
(d) Conc.HCl + ConcHNO2
Answer:
(b) Conc.HCl + Anhydrous ZnCl2

Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes

Question 6.
The reagent used to get alkyl halide from alcohol
a) PCl5
b) SOCl2
c) Both a and b
d) Cl2
Answer:
c) Both a and b

Question 7.
The reactivity of alcohols with haloacid is –
(a) 3° > 2° > 1°
(b) 1° > 2° > 3°
(c) 2° > 3° > 1°
(d) 3° > l° > 2°
Answer:
(a) 3° > 2°> 1°

Question 8.
In the preparation of alkyl halide from alkane and halogen which of the following reaction involved
a) Electrophilic addition
b) Nucleophilic addition
c) Electrophilic substitution
d) Nucleophilic substitution
Answer:
a) Electrophilic addition

Question 9.
What is the name of the reaction in which bromoethane is converted to iodoethane by reacting with NaI in acetone?
(a) Hunsdicker reaction
(b) Dow’s process
(c) Finkelstein reaction
(d) Swarts reaction
Answer:
(c) Finkelstein reaction

Question 10.
The Grignard reagent is formed when alkyl halide reacts with which one of the following
a) Mg in alcohol
b) Mg in acid
c) Mg in dry ether
d) MgO
Answer:
c) Mg in dry ether

Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes

Question 11.
Which of the following pair functional groups represents ambident nucleophiles?
(a)-SH-&-OH
(b)-CN-&-NO2
(c)-Br-&-Cl
(d)-O-&-CHO
Answer:
(b)-CN & NO2

Question 12.
Alkyl halide on reduction with Zn + HCl gives
a) alcohol
b) alkene
c) alkane
d) ether
Answer:
c) alkane

Question 13.
Which one of the following is used for producing pesticìdes?
(a) CHI3
(b) CHCl3
(c) CCl3 NO2
(d) CCl4
Answer:
(b) CHCl3

Question 14.
Which of the reactions are most common in alkyl halides
a) Nucleophilic addition
b) Electrophilic addition
c) Nucleophilic substitution
d) Electrophilic substitution
Answer:
c) Nucleophilic substitution

Question 15.
Which one of the following reacts with CH3MgI followed by hydrolysis and gives isopropyl alcohol?
(a) CH3 COCH3
(b) CH3 CHO
(c) HCHO
(d) CNCl
Answer:
(b) CH3 CHO

Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes

Question 16.
In chloroethane the carbon-bearing halogen is bonded to ________.
a) three, primary
b) two, secondary
c) one, tertiary
d) two, primary
Answer:
d) two, primary

Question 17.
Which one of the following reacts with CH3 Mg I followed by acid hydrolysis to yield acetic acid?
(a) CNCl
(b) CH3COOC2H5
(c) HCOOC2H5
(d) CO2
Answer:
(d) CO2

Question 18.
SN1reaction occurs through the intermediate formation of
a) carbocation
b) carbanion
c) free radicals
d) transition
Answer:
a) carbocation

Question 19.
Which one of the following is used as a fiber-swelling agent in textile processing?
(a) Chiorohenzene
(b) Chloroform
(c) Chlorai
(d) Chloroethane
Answer:
(a) Chiorobenzene

Question 20.
The most reactive nucleophile among the following is
a) CH3O
b) C6H5O
c) (CH3)2CHO
d) (CH3)3CO
Answer:
a) CH3O

Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes

Question 21.
Which of the following reagent is used to distinguish gem-dihalides and vicinal dihalides?
(a) Alcoholic KOH
(b) Aqueous KOH
(c) FeCl3 / Cl2
(d) Ethanol
Answer:
(b) Aqueous KOH

Question 22.
In SN2 reactions the order of reactivity of the halides.
CH3X, C2H5X , n – C3H7X, n- C4H9X is
a) CH3X > C2H5X > n – C3H7X > n – C4H9X
b) C2H5X > n – C3H7X > n – C4H9X > CH3X
c) C2H5X > n – C3H7X > n – C4H9X < CH3X
d) n – C4H9X > n – C3H7X > C2H5X > CH3X
Answer:
a) CH3X > C2H5X > n – C3H7X > n – C4H9X

Question 23.
Which one of the following is used as a metal cleaning solvent?
(a) Isopropylidene chloride
(b) Methylene chloride
(c) Chloroform
(d) lodoform
Answer:
(b) Methylene chloride

Question 24.
In Dow’s process the starting raw material is
a) Phenol
b) Chlorobenzene
c) Aniline
d) Diazobenzene
Answer:
b) Chlorobenzene

Question 25.
Which one of the following is used to test primary amines?
(a) Schiff’s test
(b) Carbylarnine test
(c) Dye test
(d) Silver mirror test
Answer:
(b) Carbyianiine test

Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes

Question 26.
Chloro benzene is ________ reactive than benzene towards electrophilic substitution and directs incoming electrophile to the ______ position.
a) more, ortho & para
b) less, ortho & para
c) more, meta
d) less, meta
Answer:
b) less, ortho & para

Question 27.
The raw material for raschig; process is
a) chloro benzene
b) phenol
c) benzene
d) anisol
Answer:
c) benzene

Question 28.
Chloro benzene on treatment with sodium in dry ether gives diphenyl. The name of the reaction is
a) Fitting reaction
b) Wurtz fittig reaction
c) Wurtz reaction
d) Sandmeyer reaction
Answer:
a) Fitting reaction

Question 29.
Which one of the following compounds does not undergo nucleophilic substitution reactions at all?
(a) Ethyl bromide
(b) Vinyl chloride
(c) Benzyl chloride
(d) isopropyl chloride
Answer:
(b) Vinyl chloride

Question 30.
The raw materials for the commercial manufacture of DDT are
a) chloro benzene and chloroform
b) chlorobenzene and chloromethane
c) chloro benzene and chloral
d) chloro benzene and iodoform
Answer:
c) chloro benzene and chloral

Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes

Question 31.
Iodoform is used as
a) anesthetic
b) antiseptic
c) analgesic
d) anti fibrin
Answer:
b) antiseptic

Question 32.
The following is used in paint removing
a) CHCl3
b) CH2Cl2
c) CCl4
d) CH3CI
Answer:
b) CH2Cl2

Question 33.
In fire extinguishers, following is used
a) CHCl3
b) CS2
c) CCl4
d) CH2Cl2
Answer:
c) CCl4

Question 34.
The following is used for metal cleaning and finishing
a) CHCl3
b) CHI3
c) CH2Cl2
d) C6H6
Answer:
c) CH2Cl2

Question 35.
First chlorinated insecticide
a) DDT
b) Gammaxene
c) Iodoform
d) Freon
Answer:
a) DDT

Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes

Question 36.
The following is used as anaesthetic
a) C2H4
b) CHCl3
c) CH2Cl2
d) DDT
Answer:
b) CHCl3

Question 37.
Freon – 12 is
a) CF3Cl
b) CHCl2F
c) CF2Cl2
d) DDT
Answer:
c) CF2Cl2

Question 38.
The name of DDT
a) p, p’ – dichloro diphenyl trichloro ethane
b) p, p’ – dichloro diphenyl trichloro ethene
C) p, p’ – dichloro diphenyl tnchloro benzene
d) p, p’ – tetra chloro ethane
Answer:
a) p, p’ – dichloro diphenyl trichloro ethane

Question 39.
Freon R – 22 is
a) CHClF2
b) CCl2F2
c) CH3Cl
d) CH2Cl2
Answer:
a) CHClF2

Question 40.
Molecular formula of DDT has
a) 5 Cl atoms
b) 4 Cl atoms
c) 3 Cl atoms
d) 2 Cl atoms
Answer:
a) 5 Cl atoms

Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes

Question 41.
What is DDT among the following
a) Green house gas
b) A fertilizer
c) Bio degradable pollutant
d) Non – Bio degradable pollutant
Answer:
d) Non – Bio degradable pollutant

Question 42.
The IUPAC name of (CH3)3CHCH2Br is
a) 1 – bromo – 2 – methyl propane
b) 2 – bromo – 2 -methyl propane
c) 1 – bromo – 1 – methyl propane
d) 2 – bromo – 1 -methylpropane
Answer:
a) 1 – bromo – 2 – methyl propane

Question 43.
IUPAC name of allyl chloride is
a) 1 – chloro ethane
b) 3 – chloro- 1 – propyne
c) 3 – chloro – 1 – propene
d) 1 – chloro propane
Answer:
c) 3 – chloro – 1 – propene

Question 44.
The number of structural isomers possible with the formula C4H9Cl are
a) 5
b) 4
c) 3
d) 2
Answer:
b) 4

Question 45.
Density is highest for
a) CH3Cl
b) CH2Cl2
c) CHCl3
d) CCl4
Answer:
d) CCl4

Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes

Question 46.
C2H5OH Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 68 X. In this reaction ‘X’ is
a) Ethanol
b) Ethylene chloride
c) ethylidene chloride
d) ethyl chloride
Answer:
d) ethyl chloride

Question 47.
Thionyl chloride is preferred in the preparation of chloro compound from alcohol since
a) Both the byproducts are gases and they escape out leaving product in pure state
b) It is a chlorinating agent
c) It is an oxidising agent
d) All other reagents are unstable
Answer:
a) Both the byproducts are gases and they escape out leaving product in pure state

Question 48.
The only alkene which gives primary alkyl halides on hydro halogenation
a) C2H4
b) C3H6
c) C4H8
d) C5H10
Answer:
a) C2H4

Question 49.
– OH cannot be replaced by – Cl if we use
a) PCl5
b) PCl3
c) S2Cl2
d) SOCl2
Answer:
c) S2Cl2

Question 50.
In the hydrohalogenation of ethylene for adding HCl, the catalyst used is
a) Anhydrous AlCl3
b) Conc. Sulphuric acid
c) Dilute Sulphuric acid
d) Anhydrous ZnCl2
Answer:
a) Anhydrous AlCl3

Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes

Question 51.
Which one of the following has the lowest boiling point?
a) CH3Cl
b) C2H5Cl
c) C2H5Br
d) C2H5I
Answer:
a) CH3Cl

Question 52.
Chloroethane is reacted with alcoholic potassium hydroxide. The product formed is
a) C2H6O
b) C2H6
c) C2H4
d) C2H4O
Answer:
c) C2H4

Question 53.
What is X in the following reaction? C2H5Cl + X → C2H5OH + KCl
a) KHCO3
b) alc. KOH
c) aq. KOH
d) K2CO3
Answer:
c) aq. KOH

Question 54.
Which of the following acids will give maximum yield of alkyl chloride in Hunsdiecker reaction
a) CH3CH2CH2COOH
b) (CH3)2CHCOOH
c) (CH3)3CCOOH
d) C6H5CH (CH3)COOH
Answer:
a) CH3CH2CH2COOH

Question 55.
In the reaction sequence
C2H5Cl + KCN X. What is the molecular formula of X is
a) C2H5CN
b) C2H5NC
c) C2H5OH
d) C2H4O
Answer:
a) C2H5CN

Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes

Question 56.
Ethyl chloride on heating with silver cyanide forms a compound X. The functional isomer of X is
a) C2H5NC
b) C2H5NCN
c) H3C – NH – CH3
d) C2H5NH2
Answer:
b) C2H5NCN

Question 57.
With Zn – Cu couple and C2H5OH, ethyl Iodide reacts to give
a) ethers
b) diethyl ether
c) Iodoform
d) Ethane
Answer:
d) Ethane

Question 58.
Ethyl bromide on boiling with alcoholic solutions of sodium hydroxide forms
a) Ethane
b) ethylene
c) ethyl alcohol
d) all of these
Answer:
b) ethylene

Question 59.
Following major compound is formed when ethyl chloride reacts with silver nitrite
a) Nitroethane
b) Ethyl nitrite
c) Ethylene
d) Acetaldehyde
Answer:
b) Ethyl nitrite

Question 60.
Which of the following represents Williamson’s synthesis?
a) CH3COOH + PCl3
b) CH3 – CH2 – Cl + CH3COOH →
c) CH3 – CH2 – ONa + CH3 – CH2 – Cl →
d) CH3 – CH2 – OH + Na →
Answer:
c) CH3 – CH2 – ONa + CH3 – CH2 – Cl →

Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes

Question 61.
The reaction of an alkyl halide with benzene in presence of anhydrous A1Cl3 gives alkyl benzene the reaction is known as
a) Friedel – craft’s reaction
b) Carbylamine reaction
c) Gattermann reaction
d) Wurtz reaction
Answer:
a) Friedel – craft’s reaction

Question 62.
A Grignard’s reagent reacts with water to give
a) ether
b) alkanes
c) amine
d) Alcohol
Answer:
b) alkanes

Question 63.
C2H5Cl + Mg → C2H5 MgCl in this reaction the solvent is
a) C2H5OH
b) Water
c) Dry ether
d) Acetone
Answer:
c) Dry ether

Question 64.
For a nucleophilic substitution reaction the rate was found in the order RI > RBr > RCl > RF then the reaction could be
a) SN1 only
b) SN2 only
c) Either SN1 or SN2
d) Neither SN1 or SN2
Answer:
c) Either SN1 or SN2

Question 65.
SN2 reaction leads to
a) inversion of configuration
b) retention of configuration
c) partial racemisation
d) no racemisation
Answer:
a) inversion of configuration

Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes

Question 66.
Which of the following alkyl halide is hydrolysed by SN1 mechanism
a) CH3Cl
b) CH3 – CH2 – Cl
c) CH3 – CH2 – CH2 – Cl
d) (CH3)3CCl
Answer:
d) (CH3)3CCl

Question 67.
SN1 reaction is favoured by
a) non – polar solvents
b) Bulky group on the carbon atom attached to the halogen atom
c) Small groups on the carbon atom attached to halogen atom
d) All of the above
Answer:
b) Bulky group on the carbon atom attached to the halogen atom

Question 68.
Which of the following is not stereospecific
a) SN1
b) SN2
c) E2
d) Addition of Br2 to ethylene in CCl4
Answer:
a) SN1

Question 69.
Which of the following factors does not favour SN1 mechanism
a) Strong base
b) Polar solvent
c) Low. conc. of nucleophile
d) 3° halide
Answer:
c) Low. conc. of nucleophile

Question 70.
The order of reactivity of various alkyl halides toward SN1 reaction is
a) 3° > 2° > 1°
b) 1° > 2° > 3°
c) 3° = 2° = 1°
d) 1° > 3° > 2°
Answer:
a) 3° > 2° > 1°

Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes

Question 71.
In aryl halides carbon atom holding halogen is
a) sp2 hybridised
b) sp hybridised
c) sp3 hybndised
d) sp3d hybridised
Answer:
a) sp2 hybridised

Question 72.
Chloro benzene can be prepared by reacting benzene diazonlum chloride with
a) HCl
b) Cu2Cl2 / HCl
c) Cl2 / AlCl3
d) HNO2
Answer:
b) Cu2Cl2 / HCl

Question 73.
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 69 + Cl2 Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 70 X, X is
a) Chlorobenzene
b) m – dichloro benzene
c) benzene hexachioride
d) p – dichlorobenzene
Answer:
a) Chlorobenzene

Question 74.
The following is an example of Sandmeyer reaction
a) C6H5N2+ Cl Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 71 C6H5Cl
b) C6H5N2+ Cl Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 72 C6H5OH
c) C6H5N2+ Cl Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 73 C6H5F
d) C6H5N2+ Cl Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 74 C6H5Cl
Answer:
a) C6H5N2+ Cl Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 71 C6H5Cl

Question 75.
Chlorobenzene on reaction with CH3Cl in presence of AlCl3 gives
a) toulene
b) m – chloro toulene
c) only o – chloro toulene
d) mixture of o – and p – chlorotoulene
Answer:
d) mixture of o – and p – chlorotoulene

Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes

Question 76.
2C6H5Cl + 2Na → X, X is
a) toulene
b) biphenyl
C) phenyl ethane
d) 1 – chloro – 2 – phenyl ethane
Answer:
b) biphenyl

Question 77.
Chlorobenzene on fusing with solid NaOH gives
a) benzene
b) benzoic acid
c) phenol
d) benzene chloride
Answer:
c) phenol

Question 78.
Chlorobenzene on nitration gives major product of
a) 1 – chloro – 4 – nitro benzene
b) 1 – chloro – 3 – nitro benzene
c) 1, 4 – dinitro benzene
d) 2, 4, 6 – tri nitro benzene
Answer:
a) 1 – chloro – 4 – nitro benzene

Question 79.
The reaction C6H5I + 2 Na + CH3I → C6H5CH3 + 2 NaI is
a) Wurtz reaction
b) Fittig reaction
c) Wurtz-Fittig reaction
d) Sandmeyer reaction
Answer:
c) Wurtz-Fittig reaction

Question 80.
R – Cl + Nal Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 75 R – I + NaCl. This reaction is
a) Wurtz reaction
b) Fittig reaction
c) Finkelstein reaction
d) Frankland reaction
Answer:
c) Finkelstein reaction

Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes

Question 81.
C2H5OH + SOCl2 Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 76 x + y + z. In this reaction x, y and z respectively are
a) C2H4Cl2, SO2, HCl
b) C2H5Cl, SO2, HCl
c) C2H5Cl, SOCl, HCl
d) C2H4, SO2, Cl2
Answer:
b) C2H5Cl, SO2, HCl’

Question 82.
C2H5Cl + AgOH → A + AgCl.
A + CH3COCl → C + HCl. “C” is
a) Ethyl acetate
b) Methyl acetate
c) butanone – 2
d) propanone
Answer:
a) Ethyl acetate

Question 83.
The compound (B) in the below reaction is:
C2H5Cl Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 77 A Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 78 B
a) ethylene chloride
b) acetic acid
c) propionic acid
d) ethyl cyanide
Answer:
c) propionic acid

Question 84.
Chloro ethane reacts with X to form diethyl ether. What is X?
a) NaOH
b) H2SO4
c) C2H5ONa
d) Na2S2O3
Answer:
c) C2H5ONa

Question 85.
1 – chlorobutane on reaction with alcoholic potash gives
a) 1 – butene
b) 1 – butanol
c) 1 – butyne
d) 2 – butanol
Answer:
a) 1 – butene

Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes

Question 86.
Propane nitrile may be prepared by heating
a) Propyl alcohol with KCN
b) ethyl chloride with KCN
c) Propyl chloride with KCN
d) ethyl chloride with KCN
Answer:
d) ethyl chloride with KCN

Question 87.
CH3CH = CH2 Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 79 A Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 141 B, B is
a) propanol – 2
b) propanal – 1
c) propanol – 1
d) propanal – 2
Answer:
c) propanol – 1

Question 88.
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 80 Y is
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 81
Answer:
c) Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 82

Question 89.
The correct order of increasing boiling points is
a) 1 – chloropropane < isopropylchloride < 1 – chlorobutane
b) isopropylchloride < 1 – chloropropane < 1 – chlorobutane
c) 1 – chlorobutane < isopropylchloride < 1 – chloropropane
d) 1 – chlorobutane < 1 – chloropropane < isopropylchloride
Answer:
b) isopropylchloride < 1 – chloropropane < 1 – chlorobutane

Question 90.
The correct order of decreasing SN2 reactivity
a) RCH2X > R2CHX > R3CX
b) RCH2X > R3CX > R2CHX
c) R2CHX > R3CX > RCH2X
d) R3CX > R2CHX > RCH2X
Answer:
a) RCH2X > R2CHX > R3CX

Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes

II. Very short question and answer (2 Marks):

Question 1.
What are haloalkanes? Give example.
Answer:
Mono halogen derivatives of alkanes are called haloalkanes. Haloalkanes are represented by general formula R – X, Where, R is an alkyl group (CnH2n + 1) – and X is a halogen atom (X = F, Cl, Br or I). Haloalkanes are further classified into primary, secondary, tertiary haloalkane on the basis of type of carbon atom to which the halogen is attached.
Example:
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 83

Question 2.
How will you convert methane into tetra chloro methane?
Answer:
Chlorination of methane gives different products which have differences in the boiling points. Hence, these can be separated by fractional distillation.
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 84

Question 3.
What is Finkelstein’s reaction?
Answer:
Chloro or bromoalkane on heating with a concentrated solution of sodium iodide in dry acetone gives iodo alkanes. This reaction is called as Finkelstein reaction.
CH3CH2Br + NaI Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 85 CH3CH2I + NaI
Bromo ethane Iodoethane

Question 4.
What is Swartz reaction?
Answer:
Chloro or bromo alkanes on heating with metallic fluorides like AgF or SbF3 gives fluoro alkanes. This reaction is called Swarts reaction.
CH3CH2Br + AgF Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 86 CH3CH2F + AgBr
Bromo ethane Fluoro ethane

Question 5.
What is Hunsdiecker’s reaction?
Answer:
Silver salts of fatty acids when refluxed with bromine in CCl4 gives bromo alkane.
CH3CH2COOAg + Br2 Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 87 CH3CH2Br + CO2 + AgBr
Silver propionate Bromo ethane

Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes

Question 6.
How is ehtyl magnesium bromide prepared from ethyl bromide?
Answer:
When a solution of ethyl bromide in ether is treated with magnesium, we get ethyl magnesium bromide.
CH3 – CH2 – Br + Mg Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 88 CH3CH2MgBr
Ethyl bromide Ethyl magnesium bromide

Question 7.
How will you convert ethyl bromide into ethyl lithium?
Answer:
Ethyl bromide reacts with active metals like sodium, lead etc in the presence of dry ether to form ethyl lithium.
CH3 CH2 Br + 2Li Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 88 CH3 CH2Li + LiBr
Ethyl bromide Ethyl Lithium

Question 8.
How is TEL prepared from ethyl bromide?
Answer:
When ethyl bromide reacts with Na / Pb alloy to give TEL.
4CH3 CH2 Br + 4Na/Pb → (CH3CH2)4Pb + 4NaBr + 3Pb
Ethyl bromide Sodium-lead alloy Tetraethyl lead (TEL)

Question 9.
Haloalkanes have higher boiling point and melting point than the parent alkane. Justify this statement.
Answer:
Haloalkanes have higher boiling point than the parent alkane having the same number of carbon atoms because the intermolecular forces of attraction and dipole-dipole interactions are comparatively stronger in haloalkanes.

Question 10.
How is methane prepared from Grignard reagent?
Answer:
Compounds like water, alcohols and amines which contain active hydrogen atom react with Grignard reagents to form alkanes.
CH3MgI + HO – H → CH4 + Mg I (OH)

CH3MgI + C2H5OH         Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 86 CH4 + MgI (OC2H5)
Ethyl alcohol                Methane

Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes

Question 11.
What are Haloarenes? Give a suitable example.
Answer:
Haloarenes are the compounds in which the halogen is directly attached to the benzene ring.
Example:
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 89

Question 12.
How is chloro benzene prepared from benzene by direct halogenation?
Answer:
Chloro benzene is prepared by the direct chlorination of benzene in the presence of lewis acid catalyst like FeCl3.
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 90

Question 13.
Write a note on Sand Meyer reaction.
Answer:
When aqueous solution of benzene diazonium chloride is warmed with Cu2Cl in HCl gives chioro benzene.
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 91

Question 14.
How is Iodo benzene prepared from benzene diazonium chloride?
Answer:
Iodo benzene is prepared by warming benzene diazonium chloride with an aqueous KI solution.
C6H5N2Cl + Kl    Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 92      C6H5I + N2 + KCl
Benzene dizonium chloride        Iodo benzene

Question 15.
What happens when ethylidene dichloride is treated with Zinc dust in methanol?
Answer:
Gem dihalides and vic – dihalides on treatment with zinc dust in methanol give alkenes.
CH3 – CHCl2 + Zn Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 93 CH2 = CH2 + ZnCl2
Ethylidene dichloride                     Ethylene

Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes

Question 16.
How will you convert chloroform into methylene chloride?
Answer:
a) Reduction of chloroform in the presence of Zn + HCl gives methylene chloride.
CHCl3 (chloroform) Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 94 CH2Cl (Methylene chloride) + HCl
b) Reduction of chloroform using H2/Ni
CHCl3 (chloroform) Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 95 CH2Cl2 (Methylene chloride) + HCl

Question 17.
Write the chlorination reaction of methane.
Answer:
Chlorination of methane gives methylene chloride
CH4 Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 96 CH3Cl Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 97 CH2Cl2
Methane                                               Methylene chloride

Question 18.
How is chloroform prepared from carbon tetrachloride?
Answer:
Carbon tetrachloride is reduced by iron powder in dilute HCl medium to form chloroform
CCl4 (carbon tetrachloride) + 2[H] Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 98 CHCl3 (chloroform) + HCl

Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes

III. Short question and answers (3 Marks):

Question 1.
write the IUPAC name of the following.
i) Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 99

ii) Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 100

iii) Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 101
Answer:
i) Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 102

ii) Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 103

iii) Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 104

Question 2.
Write the structure of the following compounds.
i) 1 – Bromo – 4 – ethyl cyclohexane
ii) 1, 4 – Dichlorobut – 2 – ene
iii) 2 – chloro – 3 – methyl pentane
Answer:
i) 1 -Bromo – 4 – ethyl cyclohexane:
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 105

ii) 1, 4 – Dichlorobut – 2 – ene
– Cl – CH2 – CH = CH – CH2 – Cl

iii) 2 – chloro – 3 – methyl pentane
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 106

Question 3.
Write any three methods of preparation of chloro ethane from ethanol.
Answer:
a) Reaction with hydrogen halide:
Ethanol is heated with HCl in presence of anhydrous ZnCl2 to give ethyl chloride.
CH3CH2OH + HCl Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 107 CH3CH2Cl + H2O
Ethanol Chloroethane

b) Reaction with phosphorous halides:
Ethanol reacts with PCl5 or PCl3 it gives ethyl chloride.
CH3CH2OH + PCl5 → CH3CH2Cl + POCl3 + HCl
Ethanol                      Chloro ethane

3 CH3CH2OH + PCl3 → 3CH3CH2Cl + H 3PO3
Ethanol                        Chloro ethane

C) Reaction with thionyl chloride (Sulphonyl chloride):
When ethanol reacts with SOCl2 in presence of pyridine, it gives chloro ethane.
CH3CH2OH + SOCl2 Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 108 CH3CH2Cl + SO2 + HCl
Ethanol                                            Chloro ethane

Question 4.
What happens when haloalkane reacts with aqueous alkali or most silver oxide?
Answer:
Ethyl bromide reacts with aqueous solution of KOH or moist silver oxide (Ag2O/H2O) to form ethanol.
CH3 – CH2 – Br + KOH (aq) Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 109 CH3CH2 – OH + KBr
Bromoethane                                   Ethyl alcohol

CH3 – CH2 – Br   +   AgOH(aq)   Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 109 CH3CH2 – OH + AgBr
Bromoethane         Moist silver oxide            Ethanol

Question 5.
Explain the ammonolysis reaction of bromo ethane.
Answer:
Ethyl bromide reacts with alcoholic ammonia solution to form ethylamine.
CH3 – CH2 – Br + H – NH2 → CH3 CH2 – NH2 + HBr
Bromo ethane                        Ethyl amine

Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 110
However, with excess of ethyl bromide, secondary and tertiary amines along with quaternary ammonium salts are obtained.

Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes

Question 6.
Explain the hydrolysis of 2-bromobutane with aqueous KOB.
Answer:

  • 2-bromobutane is optically active and it undergoes SN1 reaction with aqueous KOH.
  • The product obtained will be an optically inactive racemic mixture.
  • As nucleophilic reagent OH ion can attack the carbocation from both sides to form equal proportions of dextro and levorotatory optically active isomers, it results in the formation of an optically inactive racemic mixture.

Question 7.
How are the following compounds prepared from bromo ethane?
i) Ethane thiol
(ii) Diethyl ether
Answer:
i) Ethane thiol:
Ethyl bromide reacts with sodium or potassium hydrogen sulphide to form thio alcohols.
CH3CH2Br Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 111 CH3CH2SH + NaBr
Bromo ethane                           Ethane thiol

ii) Diethyl ether:
Ethyl bromide, when boiled with sodium alkoxide gives diethyl ether. This method can be used to prepare mixed (unsymmetrical) ethers also.
CH3 – CH2Br +      NaOCH2CH3      Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 112    CH3CH2 – O – CH2CH3 + NaBr
Bromo ethane        Sodium ethoxide                 diethyl ether

Question 8.
How is ethane prepared from the following compounds?
i) Bromo ethane ii) Iodo ethane
Answer:
i) From bromo ethane:
Ethyl bromide is reduced to ethane by treating with H2 in the presence of metal catalyst like nickel, palladium etc or with hydroiodic acid in the presence of red phosphrous.
Ni(or)Pd
CH3CH2Br + H2 Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 113 CH3 – CH3 + HBr
Bromo ethane                              Ethane

ii) From iodo ethane:
Iodo ethane is reduced with H2 in presence of Red P it gives ethane.
CH3CH2I + HI Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 114 CH3 – CH3 + I2
Iodo ethane                         Ethane

Question 9.
What are the uses of carbon tetrachioride?
Answer:

  • Carbon tetrachioride in used as a dry cleaning agent.
  • It is used as a solvent for oils, fats and waxes.
  • As the vapours of CCl4 is non-combustible, it is used under the name pyrene for extinguishing the fire caused by oil (or) petrol.

Question 10.
Write the uses of Grignard reagents.
Answer:

  1. Grignard reagents are synthetically very useful compounds. These reagents are converted to various organic compounds like alcohols, carboxylic acids, aldehydes and ketones.
  2. The alkyl group being electron rich acts as a carbanion or a nucleophile.
  3. They would attack polarized molecules at a point of low electron density. The following reactions illustrate the synthetic uses of the Grignard reagent.

Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes

Question 11.
What is Balz – Schiemann reaction?
Answer:
Fluoro benzene is prepared by treating benzene diazonium chloride with fluoro boric acid. This reaction produces diazonium fluoroborate which on heating produces fluorobenzene. This reaction is called Balz – Schiemann reaction.
C6H5N2Cl + HBF4 Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 115 C6H5N2 + BF4 Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 116 C6H5 F + BF3 + N2
Benzene diazonium chloride                                          Fluorobenzene

Question 12.
What are the uses of chlorobenzene?
Answer:

  • Chlorobenzene is used in the manufacture of pesticides like DDT.
  • It is used as high boiling solvent in organic synthesis.
  • It is used as a fibre – swelling agent in textile processing.

Question 13.
How is ethylidene dichloride prepared from
(i) Acetaldehyde
(ii) Acetylene
Answer:
i) Treating acetaldehyde with PCl5:
CH3CHO (Acetaldehyde) + PCl5 → CH3CHCl2 (Ethylidene dichloride) + POCl

ii) Adding hydrogen chloride to acetylene
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 117

Question 14.
How is ethylene dichloride prepared from
(i) Chloride?
(ii) PCl5?
Answer:
i) Addition of chlorine to ethylene
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 118

ii) Action of PCl5 (or HCl) on ethylene glycol

Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 119

Question 15.
What happens when the following compounds are treated with alcoholic KOH?
i) Ethylidene dichloride
ii) Ethylene dichloride
Answer:
i) Ethylidene dichloride:
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 120

ii) Ethylene dichloride:
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 121

Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes

Question 16.
What are the uses of methylene chloride?
Answer:
Methylene chloride is used as:

  • Aerosol spray propellant.
  • Solvent in paint remover.
  • Process solvent in the manufacture of drugs.
  • A metal cleaning agent.

Question 17.
How are the following compounds prepared from chlorobenzene?
i) Benzene
ii) Phenyl magnesium chloride
Answer:
i) C6H6 (Benzene):
Chlorbenzene undergoes reduction with Ni – Al alloy in the presence of NaOH gives benzene.
C6H5Cl + 2(H) Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 122 C6H6 + HCl
Chloro benzene              Benzeneide

ii) Phenyl Magnesium chloride:
Chloro benzene reacts with magnesium to form phenyl magnesium chloride in tetra hydrofuran (THF).
C6H5Cl (Chloro benzene) + Mg Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 123 C6H5MgCl (Phenyl magnesium chloride)

Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes

IV. Long question and answers (5 Marks):

Question 1.
Explain the SN2 mechanism of haloalkanes with a suitable example.
Answer:
S2 stands for bimolecular nucleophilic substitution
“S” stands for substitution
“N” stands for nucleophilic
“2” stands for bimolecular (two molecules are involved in the rate-determining step)
The rate of SN2 reaction depends upon the concentration of both alkyl halide and the nucleophile.
Rate of reaction = k2 [alkyihalide] [nucleophile]
This SN2 reaction follows second-order kinetics and occurs in one step.

This reaction involves the formation of a transition state in which both the reactant molecules are partially bonded to each other. The attack of nucleophile occurs from the backside and the halide ion leaves from the front side. The carbon at which substitution ocurs ha inverted configuration during the course of reaction just as an umbrella has tendency to invert in a wind storm. This inversion of configuration is called Walden inversion; after paul Walden who first discovered the inversion of configuration of a compound in SN2 reaction.

We understand SN2 reaction mechanism by taking an example of reaction between chloromethane and aqueous KOH. SN2 reaction of an optically active haloalkane is always accompanied by inversion of configuration at the asymmetric centre.

Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 124

 

Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes

Question 2.
Explain the SN1 mechanism of haloalkanes with suitable examples.
Answer:
SN1 stands for unimolecular nucleophilic substitution
‘S’ stands for substitution
‘N’ stands for nucleophilic
‘1’ stands for unimolecular (one molecule is involved in the rate-determining step)
The rate of the following SN1 reaction depends upon the concentration of aikyl halide (RX) and is independent of the concentration of the nucleophile (OH-).
Rate of the reaction = k[alkyl halide]
R – Cl + OH → R – OH + Cl
This SN1 reaction follows first order kinetics and occurs in two steps.
We understand SN1 reaction mechanism by taking a reaction between tertiary hutyl bromide with aqueous KOH.
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 125

This reaction takes place in two steps aas shown below.

Step – 1:
Formation of carbocation:
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 126
t – butyl bromide

The polar C – Br bond breaks forming a carbocation and bromide ion. This step is slow and hence it is the rate-determining step.

Step 2:
Nucleophilic attack on carbocation
The carbocation immediately reacts with the nucleophile. This step is fast and hence does not affect the rate of the reactions.
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 127

As shown above, the nucleophilic reagent OH~ can attack carbocation from both the sides, they will be a mirror image of each other.

In the above example, the substrate tert-butyl bromide is not optically active, hence the obtained product is optically inactive. If halo alkane substrate is optically active then, the product obtained will be an optically inactive racemic mixture. As nucleophilic reagent OH- can attack carbocation from both the sides, to form an equal proportion of dextro and levorotatory optically active isomers which form optically inactive racemic mixture.

Example: Hydrolysis of optically active 2- Bromo butane gives racemic mixture of ±butan-2-ol.

Question 3.
Explain the E2 reaction mechanism with a suitable example.
Answer:
E2 stands for bimolecular elimination reaction
‘E’ stands for elimination
‘2’ stands for bimolecular
The rate of E2 reaction depends on the concentration of alkyl halide and base

Rate = k2 [alkyl halide] [base]
It is therefore, a second-order reaction generally primary alkyl halide undergoes this reaction in the presence of alcoholic KOH. E2 is a one-step process in which the abstraction of the proton from the p carbon and expulsion of halide from the carbon occurs simultaneously. The mechanism is shown below.
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 128

Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes

Question 4.
Explain the E1 reaction mechanism with a suitable example.
Answer:
E1 stands for unimolecular elimination reaction
‘E’ stands for elimination ‘1’ stands for unimolecular
The rate of E1 reaction depends on the concentration of alkyl halide only and hence
rate = k [alkyl halide]
Generally, tertiary alkyl halide which undergoes elimination reaction by this mechanism in the presence of alcoholic KOH following first order kinetics is a two step process. The mechanism is shown by taking following example.
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 129

step – 1:
Heterolytic fission to yield a carbocation:
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 130

Step – 2:
Elimination of a proton from the β – carbon to produce an alkene:
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 131

Question 5.
How are the following compounds prepared from Methyl magnesium iodide?
(i) Ethanol
(ii) Tert-butyl alcohol
(iii) Acetaldehyde
Answer:
(i) Ethanol:
Formaldehyde reacts with methyl magnesium iodide to give addition products which on hydrolysis yield ethanol.
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 132

(ii) Tert-butyl alcohol:
Acetone reacts with methyl magnesium iodide to give an additional product which on hydrolysis yields tert butyl alcohol.
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 133

(iii) Acetaldehyde:
Ethyl formate reacts with methyl magnesium iodide and followed by acid hydrolysis, it forms Acetaldehyde.
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 134

Question 6.
How is ethylene dichloride converted into
i) Acetaldehyde
ii) Ethylene glycol
ii) Ethylene
Answer:
i) Acetaldehyde:
(Hydrolysis with aqueous NaOH or KOH)
Ethylidene chloride reacts with aqueous KOH to give acetaldehyde.
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 135

ii) Ethylene glycol :
Ethylene chloride reacts with aqueous KOH, it gives glycol.
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 136

iii) Ethylene:
Ethylene dichloride is heated with Zinc in presence of methanol gives ehtylene.
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 137

Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes

Question 7.
How are the following compounds prepared from chloroform?
(i) Phosgene
(ii) Methylene chloride
(iii) Methyl isocyanide
Answer:
(i) Phosgene:
Chloroform undergoes oxidation in the presence of light and air to form phosgene (carbonyl chloride)
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 138
Since phosgene is very poisonous, its presence makes chloroform unfit for use as an anaesthetic.

(ii) Methylene chloride:
Chloroform undergoes reduction with zinc and HCl in the presence of ethyl alcohol to form methylene chloride.
CHCl3 (Chloroform) + 2(H) Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 139 CH2Cl2 (Methylene chloride)+ Cl2

(iii) Methyl isocyanide:
Chloroform reacts with an aliphatic or aromatic primary amine and alcoholic caustic potash, to give foul-smelling alkyl isocyanide (carbylamines).
CH3NH2    +     CHCl2 + 3KOH → CH3NC + 3KCl + 3H2O
Methylamine Chloroform          Methyl isocyanide

Question 8.
Discuss the aromatic electrophilic substitutions reaction of chlorobenzene.
Answer:
Samacheer Kalvi 11th Chemistry Guide Chapter 14 Haloalkanes and Haloarenes 140

Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance

Tamilnadu State Board New Syllabus Samacheer Kalvi 11th Accountancy Guide Pdf Chapter 5 Trial Balance Text Book Back Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 11th Accountancy Solutions Chapter 5 Trial Balance

11th Accountancy Guide Trial Balance Text Book Back Questions and Answers

Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance

I. Multiple Choice Questions

Choose the correct answer.

Question 1.
Trial balance is a _______.
a) Statement
b) Account
c) Ledger
d) Journal
Answer:
a) Statement

Question 2.
After the preparation of ledger, the next step is the preparation of _______.
a) Trading account
b) Trial balance
c) Journal
d) Profit and loss account
Answer:
b) Trial balance

Question 3.
The trial balance contains the balances of _______.
a) Only personal accounts
b) Only real accounts
c) Only nominal accounts
d) All accounts
Answer:
d) All accounts

Question 4.
Which of the following is/are the objective(s) of preparing trial balance?
a) Serving as the summary of all the ledger accounts
b) Helping in the preparation of final accounts
c) Examining arithmetical accuracy of accounts
d) a, b and c
Answer:
d) a, b and c

Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance

Question 5.
While preparing the trial balance, the accountant finds that the total of the1 credit column is short by Rs. 200. This difference will be _______.
a) Debited to suspense account
b) Credited to suspense account
c) Adjusted to any of the debit balance
d) Adjusted to any of the credit balance
Answer:
b) Credited to suspense account

Question 6.
A list which contains balances of accounts to know whether the debit and credit balances are matched is _______.
a) Journal
b) Day book
c) Trial balance
d) Balance sheet
Answer:
c) Trial balance

Question 7.
Which of the following method(s) can be used for preparing trial balance?
a) Balance method
b) Total method
c) Total and Balance method
d) a, b and c
Answer:
d) a, b and c

Question 8.
The account which has a debit balance and is shown in the debit column of the trial balance is _______.
a) Sundry creditors account
b) Bills payable account
c) Drawings account
d) Capital account
Answer:
c) Drawings account

Question 9.
The difference of totals of both debit and credit side of trial balance is transferred to:
a) Trading account
b) Difference account
c) Suspense account
d) Miscellaneous account
Answer:
c) Suspense account

Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance

Question 10.
Trial balance is prepared:
a) At the end of the year
b) On a particular date
c) For a year
d) None of the above
Answer:
b) On a particular date

II. Very Short Answer Type Questions

Question 1.
What is a trial balance?
Answer:
A trial balance is a statement containing the debit and credit balances of all ledger accounts on a particular date. It is arranged in the form of debit and credit columns placed side by side and prepared with the object of checking the arithmetical accuracy of entries made in the books of accounts and to facilitate the preparation of financial statements.

Question 2.
Give the format of trial balance.
Answer:
Trial balance is prepared in the following format under the balance method:
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 1

Question 3.
What are the methods of preparation of trial balance?
Answer:
Trial Balance is prepared in the following methods:
Balance method: In this method, the balance of every ledger account either debit or credit, as the case may be, is recorded in the trial balance against the respective accounts. The balance method is widely used, as it helps in the preparation of financial statements.

Total method: Under this method, the total amounts on the debit side of the ledger accounts and the total amounts on the credit side of the ledger accounts are ascertained and recorded in the trial balance. This method is not commonly used as it cannot help in the preparation of financial statements.

Total and Balance method: This method is a combination of both the total method and the balance method. Under this method, four columns are provided, namely,

  • Totals of the debit side of the ledger accounts,
  • Totals of the credit side of the ledger accounts
  • Debit balances of ledger accounts and
  • Credit balances of the ledger accounts. This method is not in practice.

Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance

Question 4.
State whether the balance of the following accounts should be placed in the debit or the credit column of the trial balance:
(i) Carriage outwards
(ii) Carriage inwards
(iii) Sales
(iv) Purchases
(v) Bad debts
(vi) Interest paid
(vii) Interest received
(viii) Discount received
(ix) Capital
(x) Drawings
(xi) Sales returns
(xii) Purchase returns
Answer:
 Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 2

III. Short Answer Questions

Question 1.
What are the objectives of preparing a trial balance?
Answer:
The trial balance is prepared with the following objectives:
1. Test of arithmetical accuracy:
Trial balance is the means by which the arithmetical accuracy of the book-keeping work is checked. When the totals of the debit column and credit column in the trial balance are equal, it is assumed that posting from subsidiary books, balancing of ledger accounts, etc. are arithmetically correct. However, there may be some errors that are not disclosed by the trial balance.

2. Basis for preparing final accounts:
Financial statements, namely, trading and profit and loss account and balance sheet are prepared on the basis of a summary of ledger balances obtained from the trial balance.

3. Location of errors:
When the trial balance does not tally, it is an indication that certain errors have occurred. The errors may have occurred at one or more of the stages of the accounting process, namely, journalizing or recording in subsidiary books, totaling subsidiary books, posting in ledger accounts.

Balancing the ledger accounts, carrying ledger account balances to the trial balance and totaling the trial balance columns, etc. Hence, the errors should be located and rectified before preparing the financial statements.

4. Summarised information of ledger accounts:
The summary of ledger accounts is shown in the trial balance. Ledger accounts have to be seen only when details are required in respect of an account.

Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance

Question 2.
What are the limitations of trial balance?
Answer:
The following are the limitations of trial balance:

  1. It is possible to prepare a trial balance of an organization, only if the double-entry system is followed.
  2. Even if some transactions are omitted, the trial balance will tally.
  3. The trial balance may tally even though errors are committed in the books of account.
  4. If the trial balance is not prepared in a systematic way, the final accounts prepared on the basis of trial balance may not depict the actual state of affairs of the concern.
  5. Agreement of trial balance is not conclusive proof of arithmetical accuracy of entries made

Question 3.
‘A trial balance is only a prima facie evidence of the arithmetical accuracy of records’. Do you agree with this statement? Give reasons.
Answer:
Yes, I agree with the statement. ‘A trial balance is only a prima facie evidence of the arithmetical accuracy of records.
Reasons:
Trial balance is the means by which the arithmetical accuracy of the book – keeping. work is checked. When the totals of the debit column and credit column in the trial balance are equal, it is assumed that porting from subsidiary books, balancing of ledger accounts, etc.

IV. Exercises 

Question 1.
Prepare a trial balance with the following information:
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 3
Solution:
Trial Balance:
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 4

Question 2.
Prepare the trial balance from the following information:
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 5
Solution:
Trial Balance:
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 6

Question 3.
Prepare the trial balance from the following balances of Chandramohan as on 31st March, 2017.
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 7
Solution:
In the books of Chandramohan Trial balance as on 31st March 2017
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 8

Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance

Question 4.
Prepare the trial balance from the following balances of Babu as on 31st March, 2016.
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 9
Solution:
In The Books of Arjun Trial Balance As On 31st March 2018
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 10

Question 5.
From the following balances of Arjun, prepare the trial balance as on 31st March, 2018.
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 11
Solution:
In The Books of Arjun Trial Balance As On 31st March 2018
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 12

Question 6.
Prepare the trial balance from the following balances of Rajesh as on 31st March, 2017.
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 13
Solution:
In The Books of Rajesh Trial Balance as on 31st March 2017
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 14

Question 7.
Prepare the trial balance from the following balances of Karthik as on 31st March, 2017.
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 15
Solution:
In the books of Karthik Trial Balance as on 31st March 2018
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 16

Question 8.
From the following balances of Rohini, prepare the trial balance as on 31st March, 2016.
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 17
Solution:
In the books of Rohini Trial Balance as on 31st March 2018
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 18

Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance

Question 9.
Balan who has a car driving school gives you the following ledger balances. Prepare trial balance as on 31st December, 2016.
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 19
Solution:
In the books of Balan Trial Balance as on 31st December 2016.
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 20

Question 10.
The following balances are extracted from the books of Ravichandran on 31st December, 2016.
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 21
Solution:
In the books of Ravichandran Trial Balance as on 31st December 2016
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 22

Question 11.
From the following balances, prepare trial balance of Baskar as on 31st March, 2017. Transfer the difference, if any, to suspense account.
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 23
Solution:
In the books of Baskar Trial Balance as on 31st March 2017
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 24

Question 12.
From the following balances extracted from the books of Rajeshwari as on 31st March, 2017, prepare the trial balance.
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 25
Solution:
In the books of Baskar Trial Balance as on 31st March 2017
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 26

Question 13.
Correct the following trial balance.
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 27
Solution:
Trial Balance:
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 28

Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance

11th Accountancy Guide Trial Balance Additional Important Questions and Answers

I. Choose the correct answer.

Question 1.
Trial Balance shows arithmetical accuracy of ledger accounts, but it is not a _______ of accuracy.
a) Conclusive
b) Exclusive
c) Submissive
d) Inclusive
Answer:
a) Conclusive

Question 2.
The statement showing balance of all the ledger accounts is known as _______.
a) Trial balance
b) Balance sheet
c) Bank reconciliation statement
d) Profit and loss account
Answer:
a) Trial balance

Question 3.
Which of the following in Trial Balance is contradictory to each other?
a) Inventory and Drawings
b) Sales and Purchases returns
c) Carriage inwards and outward
d) Trade receivable and Liability
Answer:
d) Trade receivable and Liability

Question 4.
Closing stock in the Trial Balance implies that _______.
a) It is already adjusted in the opening stock
b) It is adjusted in sales account
c) It is adjusted in the purchases account
d) None of these
Answer:
c) It is adjusted in the purchases account

Question 5.
The preparation of trial balance is for _______.
a) Locating errors of commission
b) Locating errors of principle
c) Locating clerical errors
d) All of the above
Answer:
d) All of the above

Question 6.
_______ Us Hie most popular method of preparing trial balance.
a) Balance Method
b) Net Asset Method
c) Average Trial Balance method
d) None of the above
Answer:
a) Balance Method

Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance

Question 7.
When adjusted purchase is shown on the debit column of the trial balance then
a) Both opening and closing stock do not appear in the trial balance
b) Closing stock is shown in the trial balance and not the opening stock
c) Opening stock is shown in the trial balance and not the closing stock
d) Both opening and closing stock appear in the trial balance
Answer:
b) Closing stock is shown in the trial balance and not the opening stock

Question 8.
A suspense account facilitates the preparation of financial statements even when the has not tallied.
a) Cash Book
b) Ledger
c) Trial Balance
d) Journal
Answer:
c) Trial Balance

Question 9.
Trial Balance is a statement which shows _______ of all accounts.
a) Debit or Credit Balances
b) Balances and Totals
c) Positive and Negative Balances
d) Opening and Closing balances
Answer:
a) Debit or Credit Balances

Question 10.
All the following statements are correct except _______.
a) Trial balance is a statement and not an account
b) Trial balance is prepared at the end of the year
c) Trial balance is not a concluding proof of arithmetical accuracy
d) Trial balance is tallied if a transaction posted twice in the ledger
Answer:
c) Trial balance is not a concluding proof of arithmetical accuracy

Question 11.
Trial balance of a trader shows the following balances: Opening Inventory Rs.9600;Purchases less returns Rs.11850; Salaries Rs.3200;Wages Rs.750; Commission on purchases Rs.200; Carriage outwards Rs.300; Sales Rs.24900; Closing Inventory Rs.3500; Carriage on purchases Rs.1000; Gross profit will be .
a) Rs. 5,000
b) Rs. 6,500
c) Rs. 3,250
d) Rs. 3,200
Answer:
a) Rs. 5,000

Question 12.
Trial Balance is a _______.
a) Real account
b) Nominal account
c) Personal account
d) Statement
Answer:
d) Statement

Question 13.
Bank account will show _______ balance.
a) Debit
b) Credit
c) Debit (or) Credit
d) None
Answer:
a) Debit

Question 14.
Which of the following will affect the agreement of a trial balance?
a) Complete omission of a transaction
b) Partial omission of a transaction
c) Error of principle
d) Compensating errors
Answer:
b) Partial omission of a transaction

Question 15.
Trial balance is prepared to find out the _______.
a) Profit
b) loss
c) financial position
d) Arithmetical accuracy of the accounts
Answer:
d) Arithmetical accuracy of the accounts

Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance

Question 16.
Suspense account in the trial balance is entered in the
a) Trading A/c
b) Profit and loss A/c
c) Balance sheet.
d) None of the above
Answer:
c) Balance sheet.

Question 17.
Suspense account having credit balance will be shown on the _______.
a) Credit side of the profit and loss A/c
b) Liabilities side of the balance sheet
c) Assets side of the balance sheet
d) Debit side of the profit and loss A/c
Answer:
b) Liabilities side of the balance sheet

Question 18.
Suspense account having debit balance will be shown on the _______.
a) Credit side of the profit and loss A/c
b) Liabilities side of the balance sheet
c) Assets side of the balance sheet
d) Debit side of the profit and loss A/c
Answer:
c) Assets side of the balance sheet

Question 19.
While preparing the trial balance, the accountant finds that the total of the debit column is short by Rs. 1,000. This difference will be _______.
a) Debited to suspense account
b) Credited to suspense account
c) Adjusted to any of the debit balance
d) Adjusted to any of the credit balance
Answer:
a) Debited to suspense account

Question 20.
The preparation of trial balance is the step in the accounting process.
a) first
b) second
c) third
d) fourth
Answer:
c) third

Question 21.
When double entry system is followed, the totals of the debit and the Credit columns of the trial balance must be _______.
a) Equal
b) unequal
c) Excess
d) Short
Answer:
a) Equal

Question 22.
The account which has a credit balance and is shown in the debit column of the trial balance is
a) Sundry debtors account
b) Bills receivable account
c) Purchases account
d) Capital account
Answer:
d) Capital account

Question 23.
Which one the following represents correct sequence of accounting cycle _______.
a) Journal > Trial balance > Ledger > Transaction
b) Transaction > Journal > Ledger > Trial balance
c) Purchases > Journal > Ledger > Trial balance
d) None of the above
Answer:
b) Transaction > Journal > Ledger > Trial balance

Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance

Question 24.
Which one of the following is the most popular method of preparing a trial balance.
a) Total method
b) Balance method
c) Trial and error method
d) Line method
Answer:
b) Balance method

II. Very Short Answer Type Questions

Question 1.
What are the features of Trial Balance?
Answer:

  1. Trial balance contains the balances of all ledger accounts.
  2. It is prepared on a specific date. That is why, the word, “as on…” is used at the top.
  3. When double entry system is followed, the totals of the debit and the credit columns of the trial balance must be equal.
  4. If there is a difference between the totals of debit column and credit column of the trial balance, it is an indication of errors being committed somewhere.
  5. If both the debit column and the credit column of the trial balance have the same total, it does not mean that there is no mistake in accounting, since some errors are not disclosed by the trial balance.

Question 2.
What are the limitations of trial balance?
Answer:
The following are the limitations of trial balance:

  1. It is possible to prepare trial balance of an organisation, only if the double entry system is followed.
    Even if some transactions are omitted, the trial balance will tally.
  2. Trial balance may tally even though errors are committed in the books of account.
  3. If trial balance is not prepared in a systematic way, the final accounts prepared on the basis of trial balance may not depict the actual state of affairs of the concern.
  4. Agreement of trial balance is not a conclusive proof of arithmetical accuracy of entries made in the accounting records.
  5. This is because there are certain errors which are not disclosed by trial balance such as complete omission of a transaction, compensating errors and error of principle.

Question 3.
State whether the balance of the following accounts should be placed in the debit or the credit column of the trial balance:
(i) Opening Stock
(ii) Bank Loan
(iii) Provision for Bad debts
(iv) Good will
Answer:
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 29

Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance

III. Short Answer Questions

Question 1.
What is a Suspense Account?
Answer:
It is used as a place to hold unclassified or disputed funds and expenses. It is used to carry

Question 2.
What are the steps to be followed to prepare trial balance under Balance method?
Answer:
Step 1 : Calculate the balances of all ledger accounts including the cash book.

Step 2 : Record the names of the accounts in the particulars column and the amounts of debit balances in the debit column and credit balances in the credit column.

Step 3 : Enter the page number of ledger from which the balance is taken in the Ledger Folio column.

Step 4 : Total the debit and credit columns. It must be equal. If not equal, locate the errors and make the trial balance agree.

Question 3.
State whether the balance of each of the following accounts should be placed in
The debit or the credit column of the trial balance:
(1) Sundry debtors
(2) Sundry creditors
(3) Cash in hand
(4) Bank overdraft
(5) Salary
(6) Discount allowed
(7) Plant and machinery
(8) Furniture
(9) Commission earned
(10) Reserve Fund
Solution:
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 30

Question 4.
What are the advantages of a Trial Balance?
Answer:

  1. It helps to ascertain the arithmetical accuracy of the book-keeping work done during the period.
  2. It supplies in one place ready reference of all the balances of the ledger accounts.
  3. If any error is found out by preparing a trial balance, the same can be rectified before preparing final accounts.
  4. It is the basis on which final accounts are prepared.

Specimen of Trial Balance
Trial balance of Mr. X as on –
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 31

Question 5.
Prepare Trial Balance with the following information’s:
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 32
Solution:
Trial Balance
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 33

Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance

IV. Exercises

Question 1.
From the following list of balances, prepare a trial balance as on 31.3.2017.
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 34
Solution:
Trial Balance as on 31.3.2017
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 35

Question 2.
Prepare tare trial balance from the following:
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 36
Solution:
Trial Balance
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 37

Question 3.
From the following details prepare Trial Balance:
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 38
Solution:
Trial Balance
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 39

Question 4.
The following are the balances extracted from the books of Mr.M as on 31st December, 2017. Prepare Trial Balance. ,
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 40
Solution:
Trial Balance of Mr.M as on 31.12.2017
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 41

Question 5.
The following balances were extracted from the ledger of Shri Prasad on 31st March 2017. You are required to prepare a trial balance as on that date in proper form.
Solution:
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 42
Trial Balance of Shri Prasad as on 31.3.2017
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 43

Question 6.
Prepare Trail Balance.
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 44
Solution:
Trail Balance
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 45

Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance

Question 7.
Redraw correctly the trial balance given below:
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 46
Solution:
Corrected Trial Balance
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 47

Question 8.
From the following list of balances, prepare Trial Balance:
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 48
Solution:
Trial Balance
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 49

Question 9.
State whether the balances of the following accounts should be placed in debit column or credit column of the trial balance.
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 50
Solution:
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 51

Question 10.
From the under mentioned balances extracted from the books of a sole trader on 31st December. Prepare a Trial Balance as on 31st December, 2017.
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 52
Solution:
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 53

Question 11.
Prepare trial balance as on 31.12.2000 From the followings balances of Mr. Kishore Kumar
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 54
Solution:
In the book of Mr. Kishore Kumar Trial balance as on 31st December 2000
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 55

Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance

Question 12.
The following balances are extracted from the books of Mr. Anbu. Prepare trial balance as on 30.6.2004.
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 56Solution:
In the book of Mr. Anbu trial balance as on 30.06.2004
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 57

Question 13.
Prepare Trial Balance as on 31.3.2004 From the books of Mr. Praveen
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 58
Solution:
Prepare Trail Balance as 31.03.2004 from the books Mr. Praveen
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 59

Question 14.
Prepare trial balance as on 31.12.2002. From the followings balance of Mr. Ram Prasanth.
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 60
Solution:
In the books of Mr. Ram Prasanth trial balance as on 31.12.2002
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 61

Question 15.
From the extracats of Mr.Keerthivasan books of accounts prepare Trail balance as on 31.03.94.
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 62
In the books of Mr. Keerthivasan trial balance as on 31.03.1994
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 63

Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance

Question 16.
The Following details have been extracted from Mr. Kirubakaran books of accounts as on 31.12.98.
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 64
Solution:
In the books of Mr. Kirubakaran trial balance as on 31.12.1998
Samacheer Kalvi 11th Accountancy Guide Chapter 5 Trial Balance 65

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Tamilnadu State Board New Syllabus Samacheer Kalvi 11th Bio Zoology Guide Pdf Chapter 10 Neural Control and Coordination Text Book Back Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

11th Bio Zoology Guide Neural Control and Coordination Text Book Back Questions and Answers

Part – I

I. Choose The Best Options

Question 1.
Which structure in the ear converts pressure waves to action potentials?
a) Tympanic membrane
b) Organ of Corti
c) Oval window
d) Semicircular canal
Answer:
b) Organ of Corti

Question 2.
Which of the following pairings is correct
a) Sensory nerve – afferent
b) Motor nerve – afferent
c) Sensory nerve – ventral
d) Motor nerve – dorsal
Answer:
a) Sensory nerve – afferent

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 3.
During synaptic transmission of nerve impulse, a neurotransmitter (P) is released from synaptic vesicles by the action of ions
(Q). Choose the correct P and Q.
a) P = Acetylcholine, Q = Ca++
b) P = Acetylcholine, Q = Na+
c) P = GABA, Q = Na+
d) P = Cholinesterase, Q = Ca++
Answer:
a) P = Acetylcholine, Q = Ca++

Question 4.
Examine the diagram of the two cell types A and B given below and select the correct option.
a) Cell – A is the rod cell found evenly all over the retina
b) Cell – A is the cone cell more concentrated in the fovea centralis
c) Cell – B is concerned with colour vision in bright light
d) Cell – A is sensitive to bright light intensities
Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination 1
Answer:
c) Cell – B is concerned with colour vision in bright light

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 5.
Assertion- The imbalance in the concentration of Na+, K+, and proteins generates an action potential.
Reason: To maintain the unequal distribution of Na+ and K+, the neurons use electrical energy.
a) Both Assertion and Reason are true and Reason is the correct explanation of the Assertion.
b) Both Assertion and Reason are true but the Reason is not the correct explanation of Assertion.
c) Assertion is true, but Reason is false.
d) Both Assertion and Reason are false.
Answer:
a) Both Assertion and Reason are true and Reason is the correct explanation of the Assertion.

Question 6.
Which part of the human brain is concerned with the regulation of body temperature?
a) Cerebellum
b) Cerebrum
c) Medulla oblongata
d) Hypothalamus
Answer:
d) Hypothalamus

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 7.
The respiratory centre is present in the
a) Medulla oblongata
b) Hypothalamus
c) Cerebellum
d) Thalamus
Answer:
a) Medulla oblongata

Question 8.
Match the following human spinal nerves in column I with their respective number in column II and choose the correct option
Column I Column 11
(P) Cervical nerves
(Q) Thoracic nerve
(R) Lumbar nerve
(S) Coccygeal nerve
(i) 5 pairs
(ii) 1 pair
(iii) 12 pairs
(iv) 8 pairs
a) (P-iv), (Q-iii), (R-i), (S-ii)
b) (P-iii), (Q-i), (R-ii), (S-iv)
c) (P-iv), (Q-i), (R-ii), (S-iii)
d) (P-ii), (Q-iv), (R-i), (S-iii)
Answer:
a) (P-iv), (Q-iii), (R-i), (S-ii)

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 9.
Which of the following cranial nerve controls the movement of eye ball?
a) Trochlear nerve
b) Optic nerve
c) Olfactory nerve
d) Vagus nerve
Answer:
a) Trochlear nerve

Question 10.
The abundant intracellular cation is
a) H+
b) K+
c) Na+
d) Ca++
Answer:
b) K+

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 11.
Which of the following statements is wrong regarding the conduction of nerve impulse.
a) In a resting neuron, the axonal membrane is more permeable to K+ ions and nearly impermeable to Na+ ions.
b) Fluid outside the axon has a high concentration of Na+ ions and a low concentration of K+, in a resting neuron.
c) Ionic gradient s are maintained by Na+ K+ pumps across the resting membrane, which transport 3 Na ions outwards for 2K+ into the cell.
d) A neuron is polarized only when the outer surface of the axonal membrane possess a negative charge and its inner surface is positively charged.
Answer:
b) Fluid outside the axon has a high concentration of Na+ ions and a low concentration of K+, in a resting neuron.

Question 12.
All of the following are associated with the myeline sheath except
a) Faster conduction of nerve impulses
b) Nodes of Ranvier forming gaps along the axon
c) Increased energy output for nerve impulse conduction
d) Saltatory conduction of action potential
Answer:
c) Increased energy output for nerve impulse conduction

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 13.
Several statements are given here in reference to cone cells which of the following option indicates all correct statements for cone cells? Statements
(i) Cone cells are less sensitive in bright light than Rod cells
(ii) They are responsible for colour vision
(iii) Erythropsin is a photo pigment which is sensitive to red colour light
(iv) They are present in fovea of retina
a) (iii), (ii) and (i)
b) (ii), (iii) and (iv)
c) (i), (iii) and (iv)
d) (i), (ii) and (iv)
Answer:
c) (i), (iii) and (iv)

Question 14.
Which of the following statement concerning the somatic division of the peripheral neural system is incorrect?
a) Its pathways innervate skeletal muscles
b) Its pathways are usually voluntary
c) Some of its pathways are referred to as reflex arcs
d) Its pathways always involve four neurons
Answer:
d) Its pathways always involve four neurons

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 15.
When the potential across the axon membrane is more negative than the normal resting potential, the neuron is said to be in a state of
a) Depolarization
b)FIyperpo1ariation
c) Repolarization
d) Hypopolaiization
Answer:
c) Repolarization

Question 16.
Why is the blind spot called so?
Answer:
Slightly below the posterior pole of the eye, the optic nerve and the retinal blood vessels enter the eye. This region is devoid of rods and cones. Hence, this region is called a blind spot.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 17.
Sam’s optometrist tells him that his intraocular pressure is high. What is this condition called and which fluid does it involve?
Answer:

  • The increase in intraocular pressure leads to the disease called Glaucoma.
  • Any block in the canal of Schlemm increases the intraocular pressure of aqueous humor and leads to ‘Glaucoma’ where the optic nerve and the retina are compressed due to pressure.

Question 18.
The action potential occurs in response to a threshold stimulus: but not at sub-threshold stimuli. what is the name of the principle involved?
Answer:
The olfactory nerve carries the sense of smell to the sensory strip present in the cerebrum. The sensory areas are present in the parietal lobe of the cerebrum. The stimuli of smell reaches the mammillary bodies present in the hypothalamus. This produces olfactory reflexes and emotional responses to odour.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 19.
Pleasant smell of food urged Ravi to rush into the Kitchen. Name the parts of the brain involved in the identification of food and emotional responses to odour
Answer:
The hypothalamus contains a pair of small rounded body called mamillary bodies that are involved in olfactory reflexes and emotional responses to odour
This is also act as centre for appetite thirst and heat regulation.

Question 20.
Cornea transplant in humans is almost never rejected State the reason.
Answer:
Cornea does not have blood vessels. Hence there is no possibility of rejection when the cornea is transplanted from one person to another person.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 21.
At the end of repolarisation, the nerve membrane gets hyperpolarized Why?
Answer:
If repolarization becomes more negative than the resting potential – 70mV to about – 90mV it is called hyperpolarization.

Question 22.
Label the parts of the neuron.
Answer:
Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination 2
A- Nucleus with nucleolus
B- Axolemma
C- Dendrites
D- Myelin sheath, Nucleus
E- Axon (Direction of signal transmission)
F- Node of Ranvier.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 23.
The choroid plexus secretes cerebral spinal fluid List the function of it.
Answer:
Cerebrospinal fluid provides buoyancy to the central nervous system.

  1. It acts as a shock absorber for the brain and spinal cord.
  2. It nourishes the brain cells by transporting food and oxygen.
  3. It carries harmful metabolic wastes from the brain to the blood.
  4. It maintains constant pressure inside the cranial vessels.

Question 24.
What is the ANS controlling center? Name the parts that are supplied by the ANS?
Answer:
Controlling center – autonomic neural system. Controlling organs.

  1. Eyes
  2. Salivary Glands
  3. Heart
  4. Lungs
  5. Stomach
  6. Liver
  7. Kidney
  8. Intestines
  9. Bladder

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 25.
Why the limbic system is called the emotional brain. Name the parts of it?
Answer:
The limbic system is a set of components located on both sides of the thalamus present in the inner part of the cerebral hemisphere. It includes the olfactory bulbs, cingulate gyrus, mammillary body, amygdala, hippocampus, and hypothalamus. The limbic system plays a primary role in the regulation of pleasure, pain, anger, fear, sexual feeling, affection, and memory. Hence it is called the emotional brain.

Question 26.
Classify receptors based on the type of stimuli.
Answer:

Receptors Stimulus Effector organs
Mechano receptors Pressure and vibration Mechano receptors are present in the cochlea of the inner ear and the semicircular canal and utriculus
Chemoreceptors Chemicals Taste buds in the tongue and nasal epithelium
Thermo receptors Temperature Skin
Photoreceptors Light Rod and cone cells of the retina in the eye.

Question 27.
Name the first five cranial nerves, their nature and their functions
Answer:

Cranial nerves Nature of nerve Function
I. Olfactory nerve Sensory Sense of smell
II.Optic nerves Sensory Sense of sight
III. Oculo motor nerves Motor Movement of the eye
IV. Trochlear nerve Motor Rotation of the eyeball
V.Trigeminal nerve Sensory and motor mixed The functioning of face ball

Question 28.
The sense of taste is considered to be the most pleasurable of all senses. Describe the structure of the receptor involved with a diagram.
Answer:

  • The sense of taste is considered to be the most pleasurable of all senses.
  • The tongue is provided with many small projections called papillae.
  • Taste buds are located mainly on the papillae.
  • Taste buds are flask-shaped.

There are two major types.

  • Gustatory epithelial cells or taste cells.
  • Basal epithelial cells or repairing cells.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination 3

  • Long microvilli called gustatory hairs project from the tip of the gustatory cells and extend through a taste pore to the surface of the epithelium.
  • Gustatory hairs are the sensitive portion of the gustatory cells and they have sensory dendrites which send the signal to the brain.
  • The basal cells that act as stem cells divide and differentiate into new gustatory cells.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 29.
Describe the structures of olfactory receptors?
Answer:
The smell receptors are excited by air-borne chemicals that dissolve in fluids. The yellow coloured patches of olfactory epithelium form the olfactory organs that are located on the roof of the nasal cavity.

The olfactory epithelium is covered by a thin coat of mucus layer below and olfactory glands bounded connective tissues, above. It contains three types of cells: supporting cells, Basal cells and millions of pin-shaped olfactory receptor cells (which are unusual bipolar cells).

The olfactory glands and the supporting cells secrete the mucus. The unmyelinated axons of the olfactory receptor cells are gathered to form the filaments of the olfactory nerve [cranial nerve-I] which synapses with cells of the olfactory bulb.

The impulse, through the olfactory nerves, is transmitted to the frontal lobe of the brain for identification of smell and the limbic system for the emotional responses to odour.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination 4

Part-II.

11th Bio Zoology Guide Neural Control and Coordination Additional Important Questions and Answers

I. Choose The Correct Answer

Question 1.
Which of the following acts as a phagocytic cell to engulf the foreign particles at the time of any injury to the brain?
(a) Neuron
(b) Neurilemma
(c) Neuroglia
(d) Axolemma
Answer:
(b) Neurilemma

Question 2.
Name the nutritive cells of neurons.
a) Axon
b) Neuroglia
c) Schwann’s cell
d) Epithelial cells.
Answer:
b) Neuroglia

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 3.
Which of the following has bipolar neurons?
(a) Intemeurons
(b) Cranial nerves
(c) Spinal nerves
(d) Inner ear
Answer:
(d) Inner ear

Question 4.
Name the plasma membrane which surrounds the neurons?
a) Neurilemma
b) Axolemma
c) Myalin membrane
d) Sarcolemma
Answer:
a) Neurilemma

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 5.
The interior of the cell of the resting neuron is negative due to ……………….
(a) Greater efflux of Na+ outside the cell than, K+ influx into the cell.
(b) Only greater efflux of Na+ outside the cell.
(c) Greater efflux of K+ outside the cell than Na+ influx into the cell.
(d) Only greater efflux of K+ outside the cell.
Answer:
(c) Greater efflux of K+ outside the cell than Na+ influx into the cell.

Question 6.
Where are Nissl’s bodies seen in the nerve cell?
a) Cell body and dendrites
b) Cell body and axon
c) Cell body and myelin sheath
d) Cell body and end plate of the axon.
Answer:
a) Cell body and dendrites

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 7.
When the membrane potential shoots rapidly upto +45 mV, it is called the ………………….
(a) Threshold potential
(b) Spike potential
(c) Repolarization
(d) Hyperpolarization
Answer:
(b) Spike potential

Question 8.
Cell forms the myelin sheath ……………..
a) Schwaan’s cell
b) Neuroglial cells
c) Nephron
d) Epithelial cells
Answer:
a) Schwaan’s cell

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 9.
The subarachnoid space is present in between ………………..
(a) Piamater and arachnoid mater
(b) Arachnoid mater and duramater
(c) Brain and Piamater
(d) Spinal cord and duramater
Answer:
(a) Piamater and arachnoid mater

Question 10.
Which of the following does the work of phagocytosis of microbes during the infection of the brain
a) Schwann cells
b) Node of Ranvier
c) Neuroglial cells
d) Neurilemma
Answer:
c) Neuroglial cells

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 11.
Which of the following plays a key role in learning and memory?
(a) Hypothalamus
(b) Pons Varolii
(c) Thalamus
(d) Medulla oblongata
Answer:
(c) Thalamus

Question 12.
Find out the wrong pair
a) Multi polar neuron: One axon and two or more dendrites.
b) Bi polar neurons: One axon and more than two dendrites.
c) Uni polar neurons: Short process axon.
d) Synaptic Knob: Neurotransmitters
Answer:
b) Bi polar neurons: One axon and more than two dendrites.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 13.
The reflex action is effected by ……………..
(a) Brain
(b) Medulla oblongata
(c) Effector organs
(d) Spinal cord
Answer:
(d) Spinal cord

Question 14.
Match the following and find the answer.

1. Leakage channels a. Opens through the sensation of touch and pressure.
2. Ligand-gated channels b. They are stable.
3. Voltage gated channels c. Opens through chemical stimulation.
4. Charged particles d. Ionic channels are always open.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination 5
Answer:
c) i- B,ii – D,iii – C,iv – A

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 15.
Which of the following is produced at the terminal ends of the postganglionic fibres at the effector organs of the parasympathetic neural system?
(a) Noradrenaline
(b) Acetylcholine
(c) Adrenalin
(d) Melatonin
Answer:
(b) Acetylcholine

Question 16.
Where are bipolar neurons situated?
a) Cranial nerves
b) Olfactory lobes of the brain
c) Spinal nerves
d) Skin
Answer:
b) Olfactory lobes of the brain

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 17.
Which of the following absorbs light to prevent internal reflection in the eye?
(a) Sclera
(b) Retina
(c) Chorid
(d) Cornea
Answer:
(c) Chorid

Question 18.
Find out the odd one.
a) Schwann cell – Myalin sheath
b) Synaptic knob – Synaptic vesicles
c) Bipolar neuron – Cranial nerves
d) Multipolar neuron – Spinal nerves.
Answer:
c) Bipolar neuron – Cranial nerves

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 19.
The defect hypermetropia can be overcome by using ……………
(a) Concave lens
(b) Convex lens
(c) Cylindrical glass
(d) Surgical procedures
Answer:
(b) Convex lens

Question 20.
Match and find the correct sequence.

I. Neuro junction a. Neuron which receives a stimulus
II. Presynaptic neurons b. Synaptic vesicles
III. Synaptic cleft c. Synapses
IV. Neurotransmitter d. Pre and post neuron junction

a) I-d II-a II-c IV-d
b) I-a II-c III-d IV-b
c) I-a II-b III-c IV-d
d) I-c II-a III-d IV-b
Answer:
d) I-c II-a III-d IV-b

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 21.
The olfactory impulses are transmitted to the ……………….. lobe of the brain.
(a) Parietal
(b) Temporal
(c) Occipital
(d) Frontal
Answer:
(d) Frontal

Question 22.
Find out whether the following statements are true or false. Find out the correct sequence.
i. The thick outer covering of the brain is dura matter
ii. The space between pia matter and dura matter is subarachnoid space.
iii. The membrane that surrounds the brain is piamalter
iv. The space between arachnoid and pia mater is subarachnoid space
a) I – False; II – False; III – True; IV – True
b) I-True; II-False; III-True; IV-True
c) I – True; II – False; III – False; IV – True
d) I-True; II-False; III-True; IV-False
Answer:
b) I-True; II-False; III-True; IV-True

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 23.
Which of the following are present in the fingertips and soles of the feet?
(a) Pacinian corpuscles
(b) Meissner’s corpuscles
(c) Ruffini endings
(d) Krause end bulbs
Answer:
(b) Meissner’s corpuscles

Question 24.
Find out whether the following statements are true or false.
a) At resting membrane potential the efflux of potassium is more than the influx of sodium from the outer surface of the neurilemma.
b) When the stimulus is sent from the cell body to the axon there is no creation of action potential.
c) The spike potential is +45mV.
d) The threshold potential is +55mV.
i) a) True b) True c) False d) False
ii) a) False b) True c) True d) True
iii) a) True b) False c) True d) True
iv) a) True b) False c) True d) False
Answer:
iv) a) True b) False c) True d) False

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 25.
The protein part of the photopigment is ………………..
(a) Retinal
(b) Opsin
(c) Macula lutea
(d) Fovea centralis
Answer:
(A) Opsin

Question 26.
………………. is the part of the fore-brain.
a) Cerebrum – Mesencephalon
b) Cerebrum – Prosencephalon
c) Cerebrum – Diencephalon
d) Cerebrum – Parietal lobe.
Answer:
c) Cerebrum – Diencephalon

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 27.
…………………….. is useful in the diagnosis of neurological and sleep disorders.
a) PET
b) CT
c) X – rays
d) EEG
Answer:
d) EEG

Question 28.
Name the structure which connects the cerebral hemisphere
a) Choroid tissue
b) Corpus callosum
c) Neuroglia tissue
d) Pineal body
Answer:
b) Corpus callosum

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 29.
Match and find out the correct sequence.

I. Frontal lobe a. Reading
II. Parietal lobe b. Hearing
III. Temporal lobe c. Vision
IV. Occipital lobe d. Memory

a) I-d II-a III-c IV-b
b) I-a II-c III-d IV-b
c) I-a II-b III-c IV-d
d) I-d II-a III-b IV-c
Answer:
d) I-d II-a III-b IV-c

Question 30.
Assertion: Statement A- The cortex of the cerebrum consists of grey matter.
Statement B- The reason for the grey matter is due to the presence of a non – myelinated sheath.
a) Statement A- True, Statement B – False
b) Statement A and B are true
c) Statement A- False the statement B- True.
d) Statement A and B are false.
Answer:
b) Statement A and B are true

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 31.
Match and find the correct answer.
1. Broca area a. Perception of taste.
2. The pre-central gyrus b. Voluntary movements
3. The postcentral gyrus c. Aggression
4. Amygdala d. Speech function
a) I-a II-b III-c IV-d
b) I-d II-b III-c IV-a
c) I-d II-b Ill-a IV-c
d) I-a II-b III-c IV-d
Answer:
c) I-d II-b III-a IV-c

Question 32.
Assertion: Statement S – Brain controls emotions and feelings.
Statement T – There are no sensory neurons in the brain. Hence it cannot sense the pain.
a) Statement – S – True. Statement T – False
b) Statement – S – True Statement T – True
c) Statement – S – False Statement T – False
d) Statement S – False Statement T – True
Answer:
b) Statement – S – True Statement T – True

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 33.
Which is considered as the relay centre for impulses
a) Medulla oblongata
b) Cerebrum
c) Hypothalamus
d) Thalamus
Answer:
d) Thalamus

Question 34.
Which indicates A, B, C and D in the following diagram
Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination 6
(a)
a) Temporal lobe
b) Frontal lobe
c) Parietal lobe
d) Cerebellum
(b)
a) Cerebellum
b) Parietal lobe
c) Temporal lobe
d) Frontal lobe
(c)
a) Cerebellum
b) Frontal lobe
c) Temporal lobe
d) Parietal lobe
(d)
a) Parietal lobe
b) Cerebellum
c) Frontal lobe
d) Temporal lobe
Answer:
(b)
a) Cerebellum
b) Parietal lobe
c) Temporal lobe
d) Frontal lobe

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 35.
Find out the wrong statement.
a) The pre-central gyrus is called a motor strip.
b) The post-central gyrus is called a sensory strip.
c) The medulla oblongata controls respiration.
d) Wernicke area of the brain involved in the comprehension of speech.
Answer:
d) Wernicke area of the brain involved in the comprehension of speech.

Question 36.
The melatonin hormone which controls the sleep-wake cycle is secreted by
a) Pineal body
b) Thalamus
c) Hypothalamus
d) Medulla oblongata
Answer:
a) Pineal body

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 37.
The lower portion of the midbrain consists of a pair of longitudinal nervous bands called
a) Emotional brain
b) Cerebral peduncles
c) Pons
d) Vermis
Answer:
b) Cerebral peduncles

Question 38.
The cauda equina presents in
a) Cerebrum
b) Thalamus
c) Hippo cambus
d) Spinal cord
Answer:
d) Spinal cord

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 39.
Match and find the correct answer.
i) Thalamus – A) Respiration Gastric Pits.
ii) Hypothalamus – B) Vision Hearing
iii) Mid brain – C) Satiety centre
iv) Medulla oblongata – D) Learning memory
Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination 7
Answer:
a) i- D, ii – C, iii – B, iv – A

Question 40.
The cluster of nerve tissue in the cell body of neurons are called as
a) Gyri
b) Sulci
c) Vermis
d) Nerve ganglion.
Answer:
d) Nerve ganglion.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 41.
Find out the wrong pair
a) Cervical nerve – 8 pairs
b) Thoracic nerve – 12 pairs
c) Sacrum nerve – 4 pairs
d) Coccyx nerve – 1 pair
Answer:
c) Sacrum nerve – 4 pairs

Question 42.
What is the amount of cerebrospinal fluid secreted in an adult?
a) 500 ml
b) 150 ml
c) 400 ml
d) 250 ml
Answer:
b) 150 ml

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 43.
The dissolved nicotene and alcohol in …………………… and ………………… minutes reach the brain.
a) 7 and 8 minutes
b) 6 and 7 minutes
c) 7 seconds and 6 minutes
d) 7 and 5 minutes.
Answer:
c) 7 seconds and 6 minutes

Question 44.
Name the structure that regulates homeostasis.
a) Mammillary body
b) Pineal body
c) Hypothalamus
d) Pituitary.
Answer:
a) Mammillary body

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 45.
What is brain stem.
a) The structure seen in between spinal cord and cerebellum.
b) The region between Diencephalon and spinal cord
c) The region between medulla oblongata and cerebrum.
d) The region between medulla oblongata and mid-brain.
Answer:
b) The region between Diencephalon and spinal cord

Question 46.
What is the function of corpora quadri gemina?
a) Vision and hearing
b) Vision and homeostasis
c) Hearing and sense of touch
d) Hearing and vomiting.
Answer:
a) Vision and hearing

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 47.
The region has seen in the mid of the cerebellum.
a) Corpus callosum
b) Pineal body
c) Pituitary
d) Vermis.
Answer:
d) Vermis.

Question 48.
What is the function of the interneuron?
a) Impulses from afferent and efferent neurons.
b) Impulses transmitted from efferent neurons to afferent neurons.
c) Impulses transmitted from central nervous system to receptor organs
d) From nerve transmitters to the spinal cord
Answer:
a) Impulses from afferent and efferent neurons.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 49.
Which part of the brain controls the unconditioned reflux?
a) The cortex of cerebrum
b) The medulla of brain
c) Cerebellum
d) pons.
Answer:
a) The cortex of cerebrum

Question 50.
……………………..pairs of nerves from cranium and …………………….. pairs of nerves from spinal cord.
a) 10 and 31
b) 12 and 31
c) 31 and 12
d) 31 and 10.
Answer:
b) 12 and 31

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 51.
How much cerebrospinal fluid is synthesized in adults?
a) 200ml
b) 300ml
c) 150ml
d) 100ml.
Answer:
c) 150ml

Question 52.
What is the function of the vagus nerve?
a) It regulates the function of the abdominal structure
b) It regulates the speech and swallowing
c) It regulates the homeostasis of the body
d) Taste perception
Answer:
a) It regulates the function of the abdominal structure

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 53.
Name the neural system which is auto functioning and self-governed.
a) Somatic neural system
b) Automatic neural system
c) Peripheral neural system
d) Limbic system.
Answer:
b) Automatic neural system

Question 54.
Name the structure that regulates the autonomic neural system.
a) Cerebrum
b) Cerebellum
c) Hypothalamus
d) Pons.
Answer:
c) Hypothalamus

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 55.
Name the lubricating fluid which is secreted from the gland present at the base of the eyelashes.
a) Lacrymal gland
b) Cerebro-spinal fluid
c) Thymus gland
d) Sebaceous glands.
Answer:
d) Sebaceous glands.

Question 56.
Find the ABC and D in the diagram
Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination 8
a) a) Tear duct b) Sciera c) Iris d) Tear gland
b) a) Sciera b) Iris c) Tear gland d)Tear duct
c) a) Tear duct b) Iris c) Sclerad d)lTear duct
d) a) Tear gland b) Sclera c) Tear duct d) Iris.
Answer:
d) a) Tear gland b) Sclera c) Tear duct d) Iris.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 57.
Name the tissue which forms the non-vascular transparent coat cornea
a) Stratified squamous epithelium
b) Squamous epithelium
c) Canal of schlemm
d) All the above.
Answer:
a) Stratified squamous epithelium

Question 58.
Assertion: In bright light, the circular muscle in the iris contract so that the size of the pupil decreases and the light enter is regulated.
Reason: In the dim light, the radial muscle contract the pupil size increases, and less light enters the eye.
a) The assertion true but reason wrong
b) The assertion and reason are true
c) The assertion is true but reason does not explain the assertion
d) The assertion and reason are wrong.
Answer:
a) The assertion true but reason wrong

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 59.
Name the yellow flat spot at the centre of the posterior region of the retina.
a) Blind spot
b) Scelera
c) Iris
d) Maculalutea
Answer:
d) Maculalutea

Question 60.
Which colour is perceived through chloropsin is sensitive to the medium wavelength of 530 mm
a) Red cones
b) Green cones
c) Blue cones
d) Red cells.
Answer:
b) Green cones

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 61.
Name the glands that secrete tear.
a) Lacrymal gland
b) Sebaceous gland
c) Mandibular gland
d) Choroid plexues
Answer:
a) Lacrymal gland

Question 62.
…………………… enzyme is present in the tear.
a) Ptyalin
b) Lysozyme
c) Lipase
d) Erypsin.
Answer:
b) Lysozyme

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 63.
Name the structure where more cones present.
a) Foveacenlralis
b) Maculalutea
c) Retina
d) Blind spot.
Answer:
a) Foveacenlralis

Question 64.
……………………………….. people can see the nearby object but cannot see the distant object.
a) Astigmatism
b) Presbiopia
c) Hypermetropia
d) Myopia
Answer:
d) Myopia

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 65.
The concave lens helps in correct ………………. defect
a) Myopia
b) Hyper metropia
c) Astigmatism
d) Presbiopia
Answer:
a) Myopia

Question 66.
Which of the defect is depicted in the following diagram:
Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination 9
a) Emmetropia
b) Myopia
c) Hypermetropia
d) Astigmatism.
Answer:
b) Myopia

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 67.
Match and find the correct sequence.

I. Concave Surgery
II. Convex Hypermetropia
III. Cataract Astigmatism
IV. Cylindrical lens Myopia

a) 1 -a 2-b 3-c 4-c
b) 1 -d 2-b 3-a 4-c
c) 1-d 2-a 3-a 4-b
d) 1-d 2-c 3-b 4-c
Answer:
b) 1 -d 2-b 3-a 4-c

Question 68.
Name the organ which regulates vision perception and homeostasis.
a) Ear
b) Eye
c) Cerebrum
d) Cerebellum.
Answer:
a) Ear

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 69.
Find out the wrong pair.
a) Pinna – Eardrum
b) Oval window – Round window
c) Cochlea – Malleus
d) Perilymph – Endolymph
Answer:
c) Cochlea – Malleus

Question 70.
Indicate ABC and D in the Diagram.
Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination 10
a)
a) lncus
b) Eardrum
c) Organ of Corti
d) Tactoreal membrane.
b)
a) Organ of cortri
b) Incus
c) Tectoreal membrane
d)Eardrum
c)
a) Eardrum
b) Incus
c) Organ of Corti
d) Tectoreal membrane
d)
a) Eardrum
b) Incus
c) Tectoreal membrane
d) Organ of Corti
Answer:
d)
a) Eardrum
b) Incus
c) Tectoreal membrane
d) Organ of Corti

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 71.
Find out the wrong statement.
a) The equilibrium receptor regions called maculae are involved in detecting the linear movement of the head.
b) The otoliths are made up of calcium
c) The crista ampullaris is to detect rotational movement of the head
d) Severe hearing loss occurs with frequent exposure to sound with intensities greater than50db.
(The 90db will affect the hearing).
Answer:
d) Severe hearing loss occurs with frequent exposure to sound with intensities greater than50db.

Question 72.
A person on his way to a village in a car for weekend holidays after finishing the office work. As he is very tired he begins to feel drowsy. He turns up the car stereo volume opens the car window and has sips ice-cold water.
How do these actions keep him awake? The increase in the number of sensory stimuli he received is relayed to the cerebral cortex which gets activated and prevents sleeping,
a) Spinal cord
b) Cerebrum
c) Medulla oblongata
d) Cerebellum.
Answer:
c) Medulla oblongata

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 73.
Name the structure that connects the middle ear and pharynx.
a) Eustachian tube
b) Middle ear
c) Oval window
d) Organ of the cortii.
Answer:
a) Eustachian tube

Question 74.
Which part of the ear have bony labyrinth and a membranous labyrinth?
a) External ear
b) Inner ear
c) Middle ear
d) None of the above.
Answer:
b) Inner ear

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 75.
Name the structure present in the bony labyrinth.
a) Cochlea, vestibule, maleus
b) Cochlea, vestibule Incus
c) Cochlea semicircular canals, stapes
d) Cochlea, vestibule semicircular canals.
Answer:
d) Cochlea, vestibule semicircular canals.

Question 76.
Where are the stereo cilia cells present in the ear?
a) Scala media
b) Scala vestibuli
c) Scala tymnani
d) Middle ear.
Answer:
a) Scala media

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 77.
Match and find the correct sequence.

I. Meissner’s corpuscles a) continuous pressure
II. Pacinian corpuscles b) hardness, pain
III. Ruffini endings c) temperature
IV. Krause and bulbs d) light pressure

a) I-d, II-a, III-c, IV-d
b) I-d, II-b, III-c, V-a
c) I-d, II-b, Ill-a, IV-c
d) I-a, II-b, III-c, IV-d
Answer:
c) I-d, II-b, Ill-a, IV-c

Question 78.
When a cockroach tries to enter into the ear of a sleeping person, which one of the following process will start?
a) Unconditioned reflex
b) Neuro muscular fatigue
c) Stimulation of negative feedback mechanism
d) conditioned reflex
Answer:
a) Unconditioned reflex

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 79.
What is the number of nerve cells present in the brain
a) 90 million
b) 100 billion
c) 90 billion
d) 100 million
Answer:
b) 100 billion

(2 Marks)

II. Write Very Short Answer

Question 1.
What are neurons? What are their functions?
Answer:
The structural and functional unit of the nervous system is neurons. They detect, receive, process, and transmit different kinds of stimuli. They are sensory, motor, and autonomic in functions.

Question 2.
What is meant by Neuroglia? What are its functions?
Answer:
The non-nervous special cells called neuroglia from the supporting cells of the nervous tissue.

  1. Providing nourishment to the neurons
  2. Repairing the injured tissues
  3. It helps in dividing and regeneration
  4. Acting as phagocyte cells to engulf the foreign particles at the time of any injury to the brain.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 3.
Differentiate the functions of myelinated and non-myelinated neurons.
Answer:

Myelinated neuron Non-myelinated neuron
They conduct impulses rapidly Conduct impulse slowly
Present in the medulla Seen in the cortex of the cerebrum.

Question 4.
What are the functions of neuroglia?
Answer:

  1. They provide nourishment to the surrounding neurons.
  2. They involve in the memory process.
  3. They repair the injured tissue due to their dividing and regenerating capacity.
  4. They engulf the foreign particles at the time of any injury to the brain.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 5.
What is meant by nerve impulses?
Answer:
A nerve impulse is a series of electrical impulses which travel along with the nerve fibre.

Question 6.
What is a neurilemma?
Answer:
The plasma membrane covering the neuron is the neurilemma.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 7.
What is meant by threshold potential?
Answer:
During depolarization when enough Na+ ions enter the cell the action potential reaches a certain level called threshold potential. (-55 mV)

Question 8.
What are Nodes of Ranvier?
Answer:
The Schwann cells covering the axon are not continuous. There are gaps in the myelin sheath between adjacent Schwann cells. These gaps are called Nodes of Ranvier.

Question 9.
What is meant by all or none principle?
Answer:
The action potential occurs in response to a threshold stimulus but does not occur at sub-threshold stimuli. This is called the all or none principle.

Question 10.
What is Synaptic Cleft?
Answer:
A small gap between the pre and post-synaptic membranes is called Synaptic Cleft. It forms a structural gap and a functional bridge between neurons.

Question 11.
What are meninges?
Answer:
The brain is covered by the outer Duramater, the median Arachnoid mater, and the inner Piamater. These membranes are called meninges.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 12.
What is meant by lazy gate?
Answer:
During hyper polarization the K+ion gates are more permeable to K+ even after reaching threshold level it closes slowly hence called lazy gates.

Question 13.
What is subarachnoid space?
Answer:
The space between the pia mater and arachnoid mater is called subarachnoid space.

Question 14.
What is meant by repolarisation?
Answer:
When the membrane reaches the spike potential the potassium ions K+ efflux from the axolemma and hence form negative potential. This is called repolarisation.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 15.
What are mammillary bodies?
Answer:
A pair of small rounded body in the hypothalamus is called mammillary bodies. These are involved in olfactory reflexes and emotional response to odour.

Question 16.
Which decides the speed of the conduction of a nerve impulse?
Answer:

  • The conduction speed of a nerve impulse depends on the diameter of axon.
  • The greater the axon’s diameter the faster is the conduction.

Question 17.
What is septum pellucidum?
Answer:
A thin membrane which separates the lateral ventricles I and II are called the septum pellucidum.Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 18.
What is the difference between sub durai space and sub arachnoid space
Answer:

Sub durai space Sub arachnoid space
A narrow sub dural space present in between arachnoid and durameter The space between the arachnoid membrane and piameter.

Question 19.
What is meant by sulcus and gyrus? What is its functions.
Answer:

  • Gyri – The convolution seen in the cerebrum.
  • Sulci – The shallow grooves increase the surface area of the cerebral cortex.

Question 20.
What is Choroid plexus?
Answer:
The choroid plexus is a network of blood capillaries found in the roof of the ventricles. These form cerebrospinal fluid from the blood.

Question 21.
What is the function of proca?
Answer:
It involves speech function.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 22.
What are Cranial nerves?
Answer:
The 12 pairs of nerves which arise from the brain are called cranial nerves.

Question 23.
Which part of the cerebrum is called a sheet of emotions?
Answer:
The cortex of parietal occipital and temporal.

Question 24.
What is a mixed nerve?
Answer:
A nerve which contains both sensory (afferent) and motor (efferent) fibres is called a mixed nerve.

Question 25.
What are Exteroceptors?
Answer:
Exteroceptors are located at or near the surface of the body. These are sensitive to external stimuli and receive sensory impulses for hearing, vision, touch, taste, and smell.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 26.
Where is the pineal body situated? What are its functions?
Answer:
It is situated behind the choroid plexus the epithalamus forms a short stalk
Functions: The melotoxin secreted by the pineal body regulates the sleep wake cycle.

Question 27.
What are Lacrymal glands?
Answer:
Tears secreting glands located in the upper lateral region of each orbit are called Lacrymal glands.

Question 28.
What is meant by corpus callosum?
Answer:
The two hemispheres of the cerebrum are connected with the nerve band known as the corpus callosum.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 29.
What is meant by brain stem? What are its parts?
Answer:
The region between the spinal cord and diencephalon.

  1. Mid-brain
  2. Pons varoli
  3. Medulla oblongata

Question 30.
What is meant by corpora quadri gemina? What are its functions?
Answer:

  • The four papillae are seen on the dorsal side of mid brain.
  • Perception of vision and hearing

Question 31.
What is macula lutea?
Answer:
The yellow flat spot at the centre of the posterior region of the retina is called macula lutea. It is responsible for sharp detailed vision.

Question 32.
What are the functions of the cerebellum?
Answer:
The cerebellum controls and coordinates muscular movements and body equilibrium.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 33.
What is meant by receptors?
Answer:
The organ which made us aware of changes occur in our surrounding is called receptors.

Question 34.
What is meant by a voluntary neural system?
Answer:
It is the part of the peripheral neural system associated with the voluntary control of body movements via skeletal muscles

Question 35.
Name the bacteriocidal substance present in the tears? Where is it seen? Name its secretion?
Answer:

  • Lysosome enzyme
  • Seen in tears.
  • Lacrymal glands. 1ml is secreted in a day.

Question 36.
What is crista ampullaris?
Answer:
The lower end of each semicircular canal is swollen and it is called the ampulla. Each ampulla has a sensory area known as crista ampullar.

Question 37.
What are cerebral peduncles?
Answer:
The region between the diencephalon and the pons is called the midbrain. It consists of a pair of longitudinal bands of nervous tissue called cerebral peduncles.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 38.
What is a brain stem? What are its parts?
Answer:
It is the part of the brain between the spinal cord and the diencephalon.
Organs: Mid-brain, Pons, Medulla oblongata

Question 39.
What are Krause end bulbs?
Answer:
These are thermoreceptors of the skin that sense temperature.

Question 40.
Where is the enlargement region seen in the spinal cord?
Answer:

  • Cervical enlargement
  • Lumbar enlargement.

Question 41.
What is meant by reflex action?
Answer:

  • When a very quick response is needed the spinal cord can effect motor initiation as the brain and brings about an effect.
  • This rapid action by the spinal cord is called reflex action.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 42.
What is meant by the peripheral nervous system?
Answer:
All nervous tissue outside the CNS is the nervous system.

Question 43.
What is meant by mixed nerve?
Answer:
Each spinal nerve is a mixed nerve containing both afferent (sensory) and efferent (motor) fibers.

Question 44.
What is meant by pre ganglionic neuron?
Answer:
Its cell body is in the brain or spinal card. Its myelinated axon exits the CNS as part of cranial or spinal nerve and end in an autonomic ganglion.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 45.
What is autonomic ganglion?
Answer:
The axons of pre ganglionic neuron and cell bodies of post ganglionic neuron includes autonomic ganglion.

Question 46.
What is post ganglionic neuron?
Answer:
It conveys nerve impulses from autonomic ganglia to visceral effector organs.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 47.
What are the two branches of the autonomous nervous system?
Answer:

  1. Sympathetic neural system
  2. Parasympathetic neural system.
  3. varying distances is called accommodation.

Question 48.
Give short notes on Lacrymal glands?
Answer:

  • The tear secreting glands are known as Lacrymal glands.
  • 1ml of tear is secreted in a day.
  • Tear salts, mucous and lysozyme enzyme to destroy bacteria.

Question 49.
What is conjunctiva?
Answer:
It is a thin protective mucous membrane found lining the outer surface of the eye ball.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 50.
Dilation and congestion of the blood vessels due to local irritation or infections. What is the disease? When will it occur?
Answer:

  • Conjunctivitis or madras eye.
  • Irritation or infection are the cause of bloodshot eye.

Question 51.
What is sty?
Answer:
Infection of ciliary glands by bacteria causes painful pus-filled swelling called a sty.

Question 52.
What are the three types of cells present in the neural retina?
Answer:

  • Photo receptor cell
  • Cones
  • Rods
  • Bipolar and ganglion cells.

Question 53.
What is a cataract?
Answer:
Due to the changes in nature of protein the lens become an opaque called cataract.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 54.
What is aqueous humour and vitreous humour
Answer:

  • Aqueous humour – The fluid filled in between the cornea and iris.
  • Vitreous humour – Fluid filled in between lens and retina.

Question 55.
Give notes on lens fibres?
Answer:
Eye lens is transparent and biconvex made up of long columnar epithelial cells called lens fibre, these cells are formed of crystalline protein.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 56.
What are the three layers of eyeball?
Answer:

  1. Sclera – Outer coat
  2. Choroid – Pigmented middle layer
  3. Retina – Inner most layer

Question 58.
What is meant by maculae lutea?
Answer:
The yellow flat spot at the centre of the posterior region of the retina is called macula lutea. It is responsible for sharp detailed vision.

Question 59.
What is fovea centralis?
Answer:
A small depression present in the centre of the yellow spot is called fovea centralis which contains only cones.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 60.
What is a blind spot?
Answer:
The optic nerves and the retinal blood vessels enter the eye slightly below the posterior pole whichis devoid of photoreceptors is called a blind spot.

Question 61.
Why there is no cornea rejection during cornea transplantation?
Answer:

  • There is little or no possibility of cornea rejection.
  • This is because the cornea does not have blood vessels.

Question 62.
What are the three ear ossicles?
Answer:

  1. Malleus – hammer bone
  2. Incus – anvil bone
  3. Stapes – stirrup bone

Question 63.
What are the three chambers of cochlea?
Answer:

  1. Scala vestibule
  2. Scala tympani
  3. Scala media

Question 64.
What is tectorial membrane?
Answer:
A roof-like structure over hanging the organ of Corti throughout its length with the stiff gel membrane called tectorial membrane.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 65.
Name the receptors which are excited by airborne chemicals that dissolve in fluids?
Answer:
The receptors for taste and smell are the chemo receptors

Question 66.
What is a tactile Merkel disc?
Answer:
It is the light touch receptor lying in the deeper layer of the epidermis.

Question 67.
What are the structures present in the membranous labyrinth?
Answer:

  • Cochlea
  • Vestibule
  • Semi circular canals

Question 68.
What are the three chambers of cochlea? Name the membrane which separates these chambers?
Answer:

  1. Scala vestibuli
  2. Scala tympanii
  3. Scala media

Separating membranes
Reisner’s membrane. It separates scala vestibuli from scala media
Basilar membrane. It separates scala media from scala tympani.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 69.
What is meant by stereo cilia?
Answer:

  • The organ of corti contains numerous hair cells on the basilar membrane.
  • Protruding from the apical part of each hair cell is hair-like structures called stereo cilia.

Question 70.
What is proprioception?
Answer:
The ability to provide information about the position and movements of the body is proprioception.

Question 71.
What is meant by vestibular system?
Answer:
This is the organ of balance this system is composed of fluid-filled sacs and tubules.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 72.
Give notes on utriculus and sacculus?
Answer:
The utricle and saccule contain equilibrium receptor regions called maculae that are involved in detecting the linear movement of the head.

Question 73.
What is otolith?
Answer:

  • Maculae contains hair cells. These hair cells contain calcareous particles called otoliths.
  • It increases the inertia.

Question 74.
What are ampullae?
Answer:
At one end of each semicircular canal at its lower end has a swollen area called ampulla Each ampulla has sensory hair cells and supporting cells called crista ampullaris. The function is to detect the rotational movement of the head.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 75.
Give the name of balancing structures which perform the following action.

  • Linear movement of the head
  • Changes occurring in body position.
  • Rotational movement of the head

Answer:

  • Maculae
  • Vestibular system
  • Crista ampularis

Question 76.
What is the unit of sound? Give notes on our ability of sound perception?
Answer:

  • The intensity of sound is measured in decibels. (dB)
  • 0-50 dB is the threshold of hearing for normal ear.
  • Prolonged exposure to sound with intensities greater than 90dB causes hearing loss.

Question 77.
What are chemo receptors?
Answer:

  • The receptors for taste and smell are the chemo receptors
  • The smell receptors are excited by air borne chemicals that dissolve in fluids.

Question 78.
What are olfactory organs? Where are they situated?
Answer:

  • The yellow coloured patches of olfactory epithelium form the olfactory organs.
  • They are located on the roof of the nasal cavity.

Question 79.
What are papillae?
Answer:
The tongue is provided with many small projection called papillae which is responsible for taste.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 80.
Give notes on taste buds.
Answer:

  • The taste bud cells are subjected to huge amounts of friction because of their location and are routinely burned by hot foods.
  • These are the most dynamic cells in the body and replaced every seven to ten days.

 

(3 Marks)

III. Short Answers

Question 1.
What are the three main functions of nervous system.
Answer:

  • Sensory functions: It receives sensory input from internal and external environment.
    Motor functions: It transmits motor commands from the brain to the skeletal and muscular system.
  • Autonomic functions: Reflex actions.

Question 2.
How do we classify neurons on the basis of its functions.
Answer:

  • Afferent neurons – That take sensory impulses to the central nervous system from the sensory organs.
  • Efferent neurons – That carry motor impulses from CNS to the effector organ.
  • Inter neurons – That lie entirely within the CNS between the afferent and efferent neurons.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 3.
What is meant by depolarisation?
Answer:

  • The inside of the axolemma becomes positively charged and negatively charged outside.
    This reversal of electrical charge is called depolarisation.

Question 4.
How are nerve impulses transmitted?
Answer:
Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination 11

  • Inner to the axolemma the cytoplasm contains the infra cellular fluid with large amounts of potassium and magnesium phosphate with negatively charged proteins and other organic molecules.
  • Outside the axolemma contains large amounts of sodium chloride bicarbonates CO2 and metabolic wastes
  • Due to the charged particles present in the inner and outside of the axolemma are responsible for the conduction of nervous impulses.

Question 5.
What is meant by repolarisation?
Answer:

  • When the axolemma reaches the spike potential the sodium voltage – gate closes and potassium – voltage gate opens.
  • It checks influx of Na+ ions and initiation the efflux of K ions which lowers the number of positive ions within the cell. Thus the potential falls back towards the resting potential.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination 12

  • The reversal of membrane potential inside the axolemma to negative occurs clue to efflux of K+ ions. This is called repolarisation.

Question 6.
What is meant by hyper polarisation?
Answer:

  • If repolarisation becomes more negative than the resting potential -70 mV to about -90 mV.
  • It is called hyper polarisation. During this K+ ion, gate is more permeable to K+ even after reaching the threshold level as it closes slowly hence called lazy gates.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination 13

  • The membrane potential return to its original resting state when K+ ion channel close completely.
  • During hyper polarization the Na+ voltage gate remains closed.

Question 7.
Give an account of the conduction speed of a nerve impulse.
Answer:

  • If the axon’s diameter is greater the conduction will be faster.
  • The myelinated axon conducts the impulse faster than the non-myelinated axon.

Question 8.
What is meant by saltatory conduction?
Answer:
The myelinated axon conduction the impulse faster than the non – myelinated axon.
The voltage gated Na+ and K+ channels are concentrated at the nodes of Ranvier as a result the impulse jumps from node to node. This is called saltatory conduction.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 9.
Give an account of the membranes (meninges) of brain?
Answer:
Brain is covered by three cranial meninges.

  1. The outer thicker layer is duramater which lines the inner surface of the cranial cavity.
  2. The inner most layer which is adhered to the brain is the piameter.
  3. The median thin layer is arachnoid mater by a narrow subdural space.
  4. The piameter is separated from the arachnoid mater by the subarachnoid space.

Question 10.
List out the functions of brain lobes?
Answer:

Structure Function
Frontal Behaviour intelligence memory movement
Parietal Language reading sensation
Temporal Speech hearing memory
Occipital Visual processing

Question 11.
Why is thalamus considered as a important relay centre for impulse?
Answer:

  • It serves as a relay centre for impulses between the spinal and brain and cerebrum.
  • Information is sorted and edited.
  • It plays a key role in learning and memory.
  • It is a co-ordinating centre for sensory and motor signaling.

Question 12.
Why there may be a death due to the affectation of medulla oblongata?
Answer:

  • Medulla controls cardio-vascular reflexes respiration and gastric secretions.
  • If medulla is getting affected the circulation and respiration is affected.
  • That may cause a death of a person.

Question 13.
Give notes on mid brain?
Answer:

  • The midbrain is located between the diencephalon and the pons.
  • The lower portion of the mid-brain consists of a pair of longitudinal bands of nervous tissue called cerebral peduncles.
  • This relay impulses back and forth between cerebrum cerebellum pons and medulla.
  • The dorsal position of the mid Brain consist of four rounded bodies called corpora quadrigemina which acts as a reflex center for vision and hearing.

Question 14.
What are the features we develop when there is a functional deficiency of serotonin and nor epinephrine?
Answer:
Features:

  • negative mood
  • loss of interest
  • an in ability to experience pleasure
  • suicidal tendencies.

Drugs:
Anti depressant drug can treat all this features.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 15.
Give notes on cerebro spinal fluid?
Answer:

  • 150ml of cerebro spinal fluid is secreted in an adult.
  • 500ml of cerebro spinal fluid is secreted in a day.
  • Every 8 hours this fluid is rejuvenated.
  • The choroid plexus carries harmful metabolic wastes from the brain to the blood.

Question 16.
Based on their position how the receptors are classified?
Answer:
1. Exteroceptors: They are located at the surface of the body.
These senses the hearing vision touch taste and smell.

2. Introceptors: They are located in the visceral organs and blood vessels.
They are sensitive to internal stimuli.

3. Prerprioceptors:
They provide information about position and movements of the body.

Question 17.
Your friend is returning home after his visit to USA. All at home are waiting for his arrival.
How would you feel? State the division of ANS that predominates and mention few changes take place in your body?
Answer:

  • The sympathetic and parasympathetic neural system are is mainly involved.
  • On seeing his friend out of the happiness his autonomic nervous system is stimulated and he gets tears in his eyes.
  • After sometime the parasympathetic stops the secretion of tears.

Question 18.
What is meant by depression? What are its symptoms?
Answer:

  • Depression is a functional deficiency of serotonin and nor epinephrine.
  • This disorder is characterized by a pervasive negative mood, loss of interest an inability to experience pleasure and suicidal tendencies.

Question 19.
When dust falls on our eyes like eyelids close immediately not waiting for our willingness, on touching a hot pan the hand is with drawn rapidly. Do you know how this happens?
Answer:
Reflex axon.
When a very quick response is needed the spinal cord can effect motor initiation as the brain and brings about an effect it is due to fast action of spinal cord.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 20.
What are the differences between conditioned and unconditioned reflex.
Answer:

Unconditioned reflex Conditioned reflex
In born reflex for an unconditioned stimulus. It’s response to a stimulus acquired by learning.
It does not need any past experience or training Does not naturally exists in animals.
Eg: Blinking of an eye when a dust particle about to fall in it Eg: Excitement of salivary gland on seeing a food

Question 21.
What is the difference between exteroceptors and interoceptors.
Answer:

Exteroceptors Interoceptors
Located at or near the surface of the body They are located in the visceral organs and blood vessels.
These receive impulses from hearing vision touch taste and smell. They are sensitive to internal stimuli.

Question 22.
Where are lens fiber seen? What is the substance that fills it?
Answer:

  • The lens is a transparent biconvex structure made up of slender columnar epithelial cells.
  • These cells are called as lens fibre.
  • These cells are formed of crystaline protein.

Question 23.
What is meant by accommodation of eye? List the structures that are involved in this process?
Answer:

  • The ability of the eyes to focus objects at varying distances is called accommodation.
  • This is achieved by suspensory ligament ciliary muscle and ciliary body

Question 24.
Name the structures that helps in fixing eyes in the eye ball?
Answer:
Eye is held in its position with the help of six extrinsic muscles. They are

  • Superior
  • Interior
  • Lateral
  • Median rectus muscle
  • Superior oblique
  • Inferior oblique

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 25.
Name the accessory structure which protects eye?
Answer:

  • Eye lashes and the eye brows
  • They help to protect the eyeballs from foreign objects, perspiration and from direct sunrays.
  • Sebaceous glands or ciliary glands.
  • They secrete a lubricating fluid.
  • Lacrymal glands.
  • Secrete tears.
  • Tears contain salts mucus and lysozyme enzyme to destroy bacteria.

Question 26.
Give an account of aqueous humour?
Answer:

  • It supplies nutrients and oxygen to the lens cornea and retinal cells.
  • It is produced and drained at same rate.
  • It maintains a constant infra ocular pressure of about 16 mmHg.

Question 27.
Give short notes on glaucoma.
Answer:
Any block in the canal of Schlemm increases the intra ocular pressure of aqueous humour and leads to “glaucoma when the optic nerve and the retina are compressed due to pressure.

Question 28.
Name the detects of detraction.
Answer:

  • Myopia
  • Hyper metropia
  • Astigmatism
  • Cataract

Question 29.
Give notes on pigments of colour vision
Answer:

  • Redcones. It contains visual pigment erythropsin which is sensitive to long wavelength close to 560 nm.
  • Green cones – It has a pigment chloropsin which is sensitive to medium wavelength of 530 nm.
  • Blue cones – It has a pigment which is sensitive to short wavelength of 420 nm.

Question 30.
What is the difference between conducting hearing loss and neuro-sensory hearing loss?
Answer:

Conducting Hearing loss Neuro sensory
This defect is due to the blockage of ear canal with ear wax The defect may be in the organ of cortii
Rupture of ear The auditory nerve
Middle ear infection with fluid accumulation restriction of ossicular movement In the ascending auditory pathways or auditory cortex

Question 31.
Give short notes on melanin.
Answer:

  • Melanocytes synthesize melanin.
  • It gives colour to skin and protects it from the sun.
  • Vitiligo is a condition in which the melanin pigment is lost from the areas of the skin causing white patches.
  • The leukoderma appears when melanocytes fails to synthesis melanin pigment.

Question 32.
What is meant by the proprioception?
Answer:

  • Balance is part of a sense called proprioception.
  • It is the ability to sense the position orientation and movement of the body.

Question 33.
Which is the fastest renewable cells in the body? How is it affected?
Answer:
Taste buds

  • Taste buds are subjected to huge amounts of friction because of their location and are routinely burned by hot foods.
  • These cells are replaced every 7-10 days.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 34.
Name the disease which can affect people of any age gender or ethnic group. This is not the contagious disease?
Answer:
Leucoderma is a condition in which the melanin pigment is lost from areas of the skin causing white patches.

Question 35.
What are meissner’s corpuscles?
Answer:

  • These are small light pressure receptors found just beneath the epidermis in the dermal papillae.
  • They are numerous in hairless skin areas such as finger tips and soles of the feat.

(5 Marks)

IV. Brief Answers

Question 1.
Describe structure of a neuron.
Answer:
Neuron is composed of three region.

  1. Cell body
  2. Dendrites
  3. axon.

Cell body:
The cell body is spherical. There is no centriole.
The plasma membrane covering the neuron is called neurilemma and axon is axolemma.

Dendrites:
The repeatedly branched short fibres coming out of the cell bod dendrites which transmit impulses towards the cell body in it’s cytoplasm Nissl’s granules are present.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination 14
Axon:
It is a long fibre that arises from a cone shaped area of the cell body. There is no golgi bodies and Nissis granules in its cytoplasm.
The axon of peripheral nerves is surrounded by Schwann’s cells to form myelin sheath. The myelin sheath is not continuous. There are gaps in the myelin sheath between an adjacent Schwann cells called nodes of Ranvier.
Each branch at the distal end of the axon terminates into a knob like structure called synaptic knob which possesses synaptic vesicles filled with transmitters. The axon transmits nerve impulses away from the body to neuro muscular junction. The myelinated nerve cell transmits impulses faster than non – myelinated nerve cells.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 2.
Describe about the different types of neuron with diagram?
Answer:
1. Multi polar neurons:
They have many processes with one axon and two or more dendrites.

2. Bipolar neurons:
They have two processes with one axon and one dendrites.
These are found in the retina of the eye, inner ear and the olfactory area of the brain.

3. Unipolar neurons:
They have a single short process and one axon.
Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination 15

Question 3.
Give an account of Ionic channels in the axolemma?
Answer:
Ionic channels:

  1. Leakage channels
  2.  Ligand – gated channels
  3. Voltage-gated channels.

1. Leakage channels:

    • These channels are always remain open.
    • K+ leakage channels are more in number than the Na+ leakage channels.
    • Sarco lemma has greater permeability to k+ icons than Na+ icons
    • These icons keep moving continuously to maintain the potential continuously to maintain the
    • potential difference across the axo lemma.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination 16

2. Ligand – gated channels:
These are chemic called gated channels which open or close in response to a chemical stimuli.
Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination 17

  • They are located between the pre synaptic membrane of the first axon and post synaptic membrane of the second.
  • The neurotransmitter acetylcholine opens ligand channels that allow Na+ and Ca++ ions diffuse inward and K+ icon diffuse outward.

Voltage-gated channels:
Answer:
This channels open in response to a physical stimulus in the form of vibration such as touch and pressure.

  • Sodium Voltage gated channels.
  • Potassium Voltage gated channels.

Question 4.
Explain the transmission of nerve impulses?
Answer:
The transmission of impulse involves two main phases; Resting membrane potential and Action membrane potential. Resting membrane Potential: The electrical potential difference across the plasma membrane of a resting neuron is called the resting potential during which the interior of the cell is negative due to greater efflux of K+ outside the cell than Na+ influx into the cell.

When the axon is not conducting any impulses i.e. in resting condition, the axon membrane is more permeable to K+ and less permeable to Na+ ions, whereas it remains impermeable to negatively charge protein ions. The axoplasm contains high concentration of K+ and negatively charged proteins and low concentration of Na+ ions.

In contrast, fluid outside the axon (ECF) contains a low concentration of K+ and a high concentration of Na+, and this forms a concentration gradient. This ionic gradient across the resting membrane is maintained by ATP driven Sodium-Potassium pump, which exchanges 3Na+ outwards for 2K+ into the cells.

In this state, the cell membrane is said to be polarized. In neurons, the resting membrane potential ranges from -40 mV to -90 mV, and its normal value is -70 mV. The minus sign indicates that the inside of the cell is negative with respect to the outside.

Action membrane potential:
An action potential occurs when a neuron sends information down an axon, away from the cell body. It includes the following phases, depolarization, repolarization, and hyperpolarization.

Depolarization – Reversal of polarity:
When a nerve fibre is stimulated, sodium voltage-gated opens and makes the axolemma permeable to Na+ ions; meanwhile the potassium voltage-gated closes. As a result, the rate of flow of Na+ ions into the axoplasm exceeds the rate of flow of K+ ions to the outside fluid [ECF]. Therefore, the axolemma becomes positively charged inside and negatively charged outside.

This reversal of electrical charge is called Depolarization. During depolarization, when enough Na+ ions enter the cell, the action potential reaches a certain level, called threshold potential [-55 mV], The particular stimulus which is able to bring the membrane potential to the threshold is called threshold stimulus.

The action potential occurs in response to a threshold stimulus but does not occur at subthreshold stimuli. This is called the all or none principle. Due to the rapid influx of Na+ ions, the membrane potential shoots rapidly up to + 45 mV which is called the Spike potential.

Repolarisation [Falling Phase]: When the membrane reaches the spike potential, the sodium voltage-gated closes, and the potassium voltage-gated opens. It checks influx of Na+ ions and initiates the efflux of K+ ions which lowers the number of positive ions within the cell.’Thus, .the potential falls back towards the resting potential. The reversal of membrane potential inside the axolemma to negative occurs due to the efflux of K+ ions. This is called Repolarisation.

Hyperpolarization:
If repolarization becomes more negative than the resting potential -70 mV to about -90 mV, it is called Hyperpolarization. During this, K+ ion gates are more permeable to K+ even after reaching the threshold level as it closes slowly; hence called Lazy gates. The membrane potential returns to its original resting state when K+ ion channels close completely. During hyperpolarization, the Na+ voltage gate remains closed.

Conduction Speed of a nerve impulse: The conduction speed of a nerve impulse depends on the diameter of axon. The greater the axon’s diameter, the faster is the conduction.. The myelinated axon conducts the impulse faster than the non-myelinated axon.

The voltage-gated Na+ and K+ channels are concentrated at the nodes of Ranvier. As a result, the impulse jumps node to node, rather than traveling the entire length of the nerve fibre. This mechanism of conduction is called Saltatory Conduction. Nerve impulses travel at the speed of 1-300 m/s.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 5.
a) What is meant by action – membrane potential?
b) What is Depolarisation?
Answer:
a) An action potential occurs when a neuron sends information down an axon away from the cell body.
b) When a nerve fibre is stimulated sodium voltage gate opens and makes the axo lemma permeable to Na++ and the potassium voltage gate closes and potassium is getting out of the axo lemma. The concentration reduces
Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination 18

  • The axo lemma becomes positively charged inside and negatively charged outside.
  • This reversal of electrical charge is called depolarisation potential reaches level called threshold potential (-55mV)
  • The stimulus which bring this threshold potential is called threshold stimulus.
  • The action potential occur in response to a threshold stimulus but does not occur at subthreshold stimuli. This is called all or none principle.
  • Due to the rapid influx of Na+ ions the membrane potential shoots rapidly up to +45mV which is called the spike potential.

Question 6.
What is synapsis?
Answer:
Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination 19

  • The junction between two neurons is called a synapses through which a nerve impulse is transmitted,
  • The first neuron involved in the synapse forms the pre synaptic neuron and the second neuron is the post – synaptic neuron
  • A small gap between the two neuron is synaptic cleft.
  • The axon terminals contain synaptic vesicles filled with neurotransmitters.
  • When an impulse arrives at the axon terminals it depolorizes the pre – synaptic membrane opening the voltage gated calcium channels.
  • Influx of calcium ions stimulates the synaptic vesicles toward the pre – synaptic membrane and fuse with it.
  • In the neurilemma the vesicles release their neurotransmitters into the synaptic cleft by exocytosis.
  • The released neurotransmitters bind to their specific receptors.
  • The entry of the ions can generate a new potential in the post synaptic neuron.
  • This excitatory post – synaptic potential causes depolarisation and in inhibitory post – synaptic potential causes hyperpolarisation.

Question 7.
In the following diagram indicate
Answer:
(A) – Frontal
(B) – parietal
(C) – occipital
(D) – temporal lobe
Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination 20

Question 8.
Describe the structure of human brain with a diagram?
Answer:

  • The brain is located in the cranial cavity and it is covered by three cranial membranes.
  • The outer layer — durameter the inner most layer piameter and the median thin layer arachnoid. The brain is divided into three major regions. Fore brain, Mid-brain, Hind

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination 21

  • It comprises of cerebrum and diencephalon.
  • Tire cerebral cortex is composed of grey and unmyelinated nerve cells.
  • The medulla is composed of white mater.
  • The surface of the cerebrum shows many convolutions and grooves. The folds are called gyri and the shallow groove is sulci.

There are eight lobes in cerebrum.
A pair of frontals, parietals temporals and occipital lobes.
The longitudinal fissure divides the cerebrum longitudinally into two hemispheres The hemispheres are connected by a tract of nerve fibres called corpus callosum.
Cerebral cortex has three functional areas

Sensory areas:
It occurs in the parietal temporal and occipital lobes of the cortex.

Motor areas:
This controls voluntary muscular movement which lies in the posterior part of the frontal iobes.

Association area:
It lies in between cortex and diencephalan This involves in memory communication learning and reasoning.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 9.
Explain the structure of the forebrain?
Answer:
The forebrain comprises the following regions: Cerebrum and Diencephalon. The cerebrum is the ‘seat of intelligence’ and forms the major part of the brain. The cerebrum consists of an outer cortex, inner medulla and basal nuclei.

The superficial region of the cerebrum is called the cerebral cortex, which looks grey due to the presence of unmyelinated nerve cells. Cerebral cortex – consists of the neuronal cell body, dendrites, associated glial and blood vessels.

The surface of the cerebrum shows many convolutions (folds) and grooves. The folds are called gyri, the shallow grooves between the gyri are called sulci and deep grooves are called fissures. These sulci and gyri increase the surface area of the cerebral cortex. Several sulci divide the cerebrum into eight lobes; a pair of frontals, parietals, temporals and occipital lobes.

A median longitudinal fissure divides the cerebrum longitudinally into two cerebral hemispheres. A transverse fissure separates the cerebral hemispheres from the cerebellum.

The hemispheres are connected by a tract of nerve fibres called corpus callosum. Cerebral cortex has three functional areas namely sensory areas occur in the parietal, temporal and occipital lobes of the cortex. They receive and interpret the sensory impulses.

Motor area of the cortex which controls voluntary muscular movements lies in the posterior part of the frontal lobes. The areas other than sensory and motor areas are called Association areas that deal with integrative functions such as memory, communications, learning and reasoning. Inner to the cortex is medulla which is white in colour and acts as a nerve tract between the cortex and the diencephalon.

Diencephalon consists largely of following three paired structures. The epithalamus forms the roof of the diencephalon and it is a non-nervous tissue. The anterior part of the epithalamus is vascular and folded to form the choroid plexus. Just behind the choroid plexus, the epithalamus forms a short stalk that ends in a rounded body called pineal body which secretes the hormone, melatonin which regulates the sleep and wake cycle.

Thalamus is composed of grey matter which serves as a relay centre for impulses between the spinal cord, brain stem and cerebrum. Within the thalamus, information is sorted and edited and plays a key role in learning and memory. It is a major coordinating centre for sensory and motor signaling.

Hypothalamus forms the floor of the diencephalon. The downward extension of the hypothalamus, the infundibulum connects the hypothalamus with the pituitary gland. The hypothalamus contains a pair of small rounded body called mammillary bodies that are involved in olfactory reflexes and emotional responses to odour.

Hypothalamus maintains homeostasis and has many centres which control the body temperature, urge for eating and drinking. It also contains a group of neurosecretory cells which secrete the hypothalamic hormones. Hypothalamus also acts as the satiety centre.

Limbic system: The inner part of the cerebral hemisphere constitutes the limbic system. The main components of limbic system are olfactory bulbs, cingulate gyrus, mammillary body, amygdala, hippocampus and hypothalamus.

The limbic system is called the ‘emotional brain’ because it plays a primary role in the regulation of pleasure, pain, anger, fear, sexual feeling and affection. The hippocampus and amygdala also play a role in memory. Brain stem is the part of the brain between the spinal cord and the diencephalon. It consists of mid-brain, pons varolii and medulla oblongata.

Question 10.
Describe the structures of diencephalon?
Answer:
Epithalamus:

  • It is a non – nervous tissue.
  • The anterior part of epithalamus is vascular and folded to form the anterior choroid plexus.
  • The epithalamus forms a short stalk which ends in a rounded body called pineal body.
  • This secretes the hormone melotonin which regulates sleep and wake cycle.

Thalamus:

  • It is formed of grey matter
  • It serves as a relay centre for impulses between the spinal cord brain stem and cerebrum.
  • It plays a key role in learning and memory.
  • It is a major co-ordinating centre for sensory and motor signalling.

Hypothalamus:

  • It forms the floor of the diencephalon.
  • It has a pair of small rounded body called mammillary bodies
  • It involves in olfactory reflexes and emotional responses to odour.
  • It maintains homeostasis.
  • It controls the body temperature.
  • Urge for eating and drinking.
  • It also contains a group of neuro secretory cells which secrete the hypothalamic hormones.
  • It also acts as the satiety centre.

Question 11.
Explain the structure of the Hindbrain?
Answer:
Rhombencephalon forms the hindbrain. It comprises of cerebellum, pons varolii and medulla oblongata. The cerebellum is the second largest part of the brain. It consists of two cerebellar hemispheres and a central worm-shaped part, the vermis. The cerebellum controls and coordinates muscular movements and body equilibrium. Any damage to the cerebellum often results in uncoordinated voluntary muscle movements.

Pons varoli lies in front of the cerebellum between the midbrain and the medulla oblongata. The nerve fibres in the pons varolii form a bridge between the two cerebellar hemispheres and connect the medulla oblongata with the other region of the brain. The respiratory nuclei found in the pons cooperate with the medulla to control respiration.

Medulla oblongata forms the posterior-most part of the brain. It connects the spinal cord with various parts of the brain. It receives and integrates signals from spinal cord and sends it to the cerebellum and thalamus. Medulla contains vital centres that control cardiovascular reflexes, respiration and gastric secretions.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 12.
Differentiate the conditioned stimulus from unconditioned stimulus.
Answer:

Conditioned Unconditioned
1. Not through learning Acquired by learning
2. In born reflex It is not an in born reflex
3. It does not need any past experience Experience makes it a part of the behaviour
4. Eg: Blinking of an eye when a dust fall in to it. Eg: Secretion of salivary gland on seeing the food

Question 13.
Tabulate the nerves and functions and its nature of 6-12th cranial nerves.
Answer:

Cranial nerves Nature of nerve Function
I Olfactory nerve Sensory Sense of smell
II Optic nerve Sensory Sense of sight
III Oculomotor nerve Motor Movement of the eye
IV Trochlear nerve Motor Rotation of the eye ball
V Trigeminal nerve Sensory and motor (mixed) Functioning of facial parts
VI Abducens nerve Motor Rotation of the eye ball
VII Facial nerve Mixed Functioning of facial parts
VIII Auditory/ Vestibulocochlear nerve Sensory Maintains the equilibrium of the body/ Auditory function
IX Glossopharyngeal nerve Mixed Taste and touch
X Vagus Mixed Regulation of the visceral organs
XI Spinal accessory Motor Muscular movement of pharynx, larynx, neck and shoulder
XII Hypoglossal Motor Speech and swallowing

Question 14.
Tabulate the functions of sympathetic and para sympathetic nerve.
Answer:

Sympathetic nervous system Para sympathetic nervous system
1. It dialates pupil It constricts pupil of the eye
2. It inhibits the secretion of saliva It stimulates saliva secretion
3. It increases the heart beat It reduces the heart beat
4. It dialates bronches It constricts the bronchus
5. It inhibits digestion It stimulates digestion
6. It increases the glucose release It stimulates bile release
7. Stimulates epinephrine and nor epinephrine release It reduces the epinephrine and nor epinephrine release
8. Inhibits peristalsis and secretion Stimulates peristalsis and secretion
9. Reflexes bladder Contracts bladder

Question 15.
Describe the structure of the cross-section of spinal cord.
Answer:

  • There are two indentations the posterior median sulcus and the anterior median fissure.
  • In the spinal cord the grey matter forms an inner butterfly-shaped region surrounded by the outer white matter.
  • The grey matter consists of dendrites inter neurons and guai cells.
  • White matter consists of bundles of nerve fibres.
  • Each half of the grey matter is divided into a
  • Dorsal horn – Cell bodies of inter neurons.
  • Ventral horn – Efferent motor neurons supplying the skeletal muscle.
  • Lateral horn – Nerves supply to heart smooth muscles exocrine glands. Originate from the cell bodies.
  • Ascending tract – This carry sensory impulses to the brain.
  • Descending tract – This carry motor impulses to brain.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination 22

Question 16.
Give an account of the functional components of a reflex arc.
Answer:
Sensory receptor – It is a sensory structure that responds to specific stimulus.
Sensory neuron – This neuron takes the sensory impulse to the grey (afferent) matter of the
spinal cord through the dorsal root of the spinal cord.
Inter neuron – It may serve to transmit the impulses from the sensory neuron to the motor neuron.
Motor neuron – It transmits impulse from CNS to the effector organ
Effector neuron – It may be a muscle or gland which responds to the impulse received.
Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination 23

  • Lacrymal glands located in the upper lateral region of each orbit secrete tears.
  • Tears are secreted at the rate of 1 ml/day.
  • Tears contain salt mucus and lysozyme enzyme to destroy bacteria.
  • The protective mucus membrane present in the outer surface of the eye ball.
  • The eye has two compartments anterior and posterior compartments filled with aqueous humour and vitreous humour respectively.
  • The eye ball is consists of three layers sclera, vascular choroid and sensory retina.

Sclera:

  • It consists of anterior cornea and the posterior sclera.
  • Cornea is composed of stratified squamous epithelium. Sclera forms the white of the eye and protects the eyeball.
  • At the junction of the sclera and the cornea is a channel called canal of schlemm which continuously drains out the excess of aqueous humour.

Choroid layer:
It is highly vascularised pigmented layer.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 17.
Tabulate the differences between sympathetic and parasympathetic neural system.
Answer:

Sympathetic Neural System (SNS) Parasympathetic Neural System (PNS)
SNS originates in the thoracic and lumbar region of the spinal cord. PNS originates in the cranial region of the brain and the sacral region of the spinal cord.
Sympathetic ganglia are linked up to form a chain. Its ganglia remain isolated
Preganglionic fibres are short and the postganglionic fibres are long. Preganglionic fibres are long and the postganglionic fibres are short.
Noradrenaline is produced at the terminal ends of the postganglionic fibres at the effector organs. Hence the system is adrenergic. Acetylcholine is produced at the terminal ends of the postganglionic fibres at the effector organs. Hence the system is cholinergic.
Active during stressful conditions preparing the body to face them. Active during relaxing times restoring normal activity after a stress.
The overall effect is excitatory and stimulating. The overall effect is inhibitory.
It is considered as the flight or fight system. It is considered as “The rest and Digest System” or “The Feed and Breed System”.

Question 18.
Give an account of the peripheral nervous system.
Answer:

  • All nervous tissue outside the central nervous system is the peripheral neural system.
  • It includes nerves ganglia enteric plexuses and sensory receptors.
  • Ganglia are Sinai masses of nervous tissue.
  • The neurons of these plexuses help in regulating the digestive system.
  • The specialised structure that helps to respond to changes in the environment are called sensory receptor.
  • This triggers nerve impulses along the afferent fibres to CNS.
  • PNS comprises 12 pairs of cranial nerves and 31 pairs of the spinal nerve.
  • The neural retina layer consists of cones and rods.
  • The yellow flat spot at the centre of the posterior region of the retina is called macula lutea.
  • A small depression present in the centre of the

Question 19.
Explain the Autonomic Neural System?
Answer:
The autonomic neural system is auto-functioning and self-governed. It is a part of the peripheral neural system that innervates smooth muscles, glands, and cardiac muscle. This system controls and coordinates the involuntary activities of various organs. ANS controlling centre is in the hypothalamus.

An autonomic neural system comprises the following components:

  1. A preganglionic neuron whose cell body is in the brain or spinal cord; its myelinated axon exits the CNS as part of cranial or spinal nerve and ends in an autonomic ganglion.
  2. Autonomic ganglion consists of an axon of preganglionic neurons and cell bodies of the postganglionic neurons.
  3. Postganglionic neuron conveys nerve impulses from autonomic ganglia to visceral effector organs.
  4. The autonomic neural system consists of the Sympathetic neural system and the Parasympathetic neural system.

Question 20.
Draw the diagram of the cross-section of the eye.
Answer:
Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination 24

Question 21.
Describe the mechanism of vision.
Answer:

  • When light enters the eye it gets refracted by the cornea, aqueous humor and lens and it is focused on the retina and excites the rod and cone cells.
  • The rods and cones contain the retinal a derivative of vitamin A and the photo pigment opsin.
  • Light induces dissociation of retinal from opsin and causes the structural changes in opsin.
  • This generates an action potential in the photo receptor cells.
  • It is transmitted by the optic nerves to the visual cortex of the brain via the optic nerves for the perception of vision.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination 25

Question 22.
List the refractive errors of eye.
Answer:
Myopia

  • The affected person cannot see distant objects.
  • As the eyeball is elongated or thickened lens the image of distant object is formed in front of the yellow spot.
  • This error can be corrected using a concave lens.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination 26

Hypermetropia

  • Affected person cannot see the nearby objects.
  • This is due to a shortened eyeball and thin lens. So the image of closest object is converged behind the retina.
  • This defect can be corrected by using convex lens.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination 27

Presbyopia

  • Due to aging, the lens loses elasticity and the power of accommodation.
  • Convex lenses are used to correct this defect.

Astigmatism

  • It is due to the rough curvature of the cornea or lens.
  • Cylindrical glasses are used to correct this error.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 23.
Describe the structure of an ear?
Answer:
Anatomically the ear is divided into three regions external ear middle ear and inner ear.
External ear:

  • It consists of pinna external auditory meatus and ear drum.
  • The pinna collects the sound waves.
  • The external auditory meatus extends up to the tympanic membrane.
  • The tympanic membrane is covered with skin outside and with mucus membrane inside.

Middle ear:

  • It is an air-filled cavity in the temporal bone.
  • The middle ear contains three ossicles malleus incus and stapes.
  • The malleus is attached to the tympanic membrane and its head articulates with the incus.
  • The stapes is attached to the oval window in the inner ear.
  • The Eustachian tube connects the middle ear cavity with the pharynx

Inner ear:-

  • It is the fluid-filled cavity consisting of two parts the bony labyrinth and the membranous labyrinths.
  • The bony labyrinth consists of three areas, cochlea, vestibule, and semicircular canals.

a Cochlea is a coiled portion consists of 3 chambers namely.

  1. Scala vestibule
  2. Scala media
  3. Scala tympanii.

Scala vestibule and scala tympani are filled with peri lymph.
The scala media is filled with endo lymph.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination 28

Question 24.
Describe the structure and functions of organ of cortii.
Answer:

  • Organ of corti is a sensory ridge located on the top of the basilar membrane.
  • Basilar membrane contains numerous hair cells that are arranged in four rows.
  • Protruding from the apical part of each hair cell is hair like structures known as stereocilia.
  • On the organ of cortii a stiff gel membrane called tectorial membrane is situated.
  • During the conduction of sound wave sterocilia makes contact with tectorial membrane.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination 29

Question 25.
Explain the Refractive errors of the eye or defects of the human eye?
Answer:
Myopia (nearsightedness): The affected person can see the nearby objects but not the distant objects. This condition may result due to an elongated eyeball or thickened lens; so that the image of a distant object is formed in front of the yellow spot. This error can be corrected using a concave lens that diverges the entering light rays and focuses them on the retina.

Hypermetropia (long-sightedness): the affected person can see only the distant objects clearly but not the objects nearby. This condition results due to a shortened eyeball and thin lens; so the image of the closest object is converged behind the retina. This defect can be overcome by using a convex lens that converges the entering light rays on the retina.

Presbyopia:
Due to aging, the lens loses elasticity and the power of accommodation. Convex lenses are used to correct this defect. Astigmatism is due to the rough (irregular) curvature of the cornea or lens. Cylindrical glasses are used to correct this error.

Cataract:
Due to the changes in the nature of the protein, the lens becomes opaque. It can be corrected by surgical procedures.

Question 26.
Differentiate the rods from cones.
Answer:

Rods Cones
1. Helps in seeing in dim light Colour perception in bright light
2. Contains Rhodopsin pigment Contains photopsin
3. The protein retinol and vitamins aldehyde combine to form scotoptin called Rhodopsin The protein opsin and retinol combine to form photopsin.
4. There are 120 million rods are seen on the retina 6-7 million cone cells are seen on the retina
5. Rods are seen richly over the surface of the foveal region. Cones are richly present on the foveal region.

Question 27.
A man is cheating with his family in this time a house fly sits on his back at once he lifts the hand and strikes the fly. How can he know that? What are the structures involved in this perception?
Answer:
Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination 30

  • The skin senses this skin is the largest sense organ.
  • All over the skin sensory receptors of pressure heat cold and pain.
  • Following are the sensory receptors of the skin.

Tactile Merkel disc

  • It is a light touch receptor lying in the deeper layer of the epidermis.
  • Hair follicle receptors. These are light-touch receptors lying around the hair follicles.

Meissner’s corpuscles

  • These are small light pressure receptors found just beneath the epidermis in the dermal papillae.
  • They are numerous in hair less skin areas such as finger tips and soles of the feet.

Pacinian corpuscles

  • These are the large egg-shaped receptors found scattered in the dermis.
  • It detects different textures temperature hardness and pain.

Ruffini endings
This lie in the dermis responds to continuous pressure Krause end bulbs are thermo receptors that sense temperature.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 28.
Give notes on Defects of the ear.
Answer:

  • Deafness may be temporary or permanent
  • Conductive deafness
  • Possible causes
  • The blockage of the ear canal with ear wax.
  • Rupture of the ear drum.
  • Middle ear infection with fluid accumulation,
  • Restriction of ossicular movement.
  • Sensory-neural deafness
  • The defect may be in the organ of cortii or the auditory nerve or in the ascending auditory pathways or auditory cortex.

Question 29.
Give an account of the mechanism of sound?
Answer:

  • Sound waves entering the external auditory meatus fall on the tympanic membrane and get vibrated.
  • These vibrations are transmitted to the oval window through the three ear ossicles.
  • Since the tympani membrane is 17-20 times larger than the oval windows. This pressure exerted on the oval window is about 20 times more than that on the tympanic membrane.
  • This pressure causes the round window to alternately bulge outward and inward meanwhile the basilar membrane along with the organ of Corti moves up and down.
  • These movements of hair alternately open and close the mechanically gated ion channel causes action potential.
  • This is propagated to the brain as a sound sensation through the cochlear nerve.

Question 30.
Explain the sensory function of skin?
Answer:
Skin is the sensory organ of touch and is also the largest sense organ. This sensation conies from millions of microscopic sensory receptors located all over the skin and associated with the general sensations of contact, pressure, heat, cold and pain. Some parts of the body, such as the fingertips have a large number of these receptors, making them more sensitive. Some of the sensory receptors present in the skin are:

  • Tactile Merkel disc is a light touch receptor lying in the deeper layer of the epidermis.
  • Hair follicle receptors are light-touch receptors lying around the hair follicles.
  • Meissner’s corpuscles are small light pressure receptors found just beneath the epidermis in the dermal papillae. They are numerous in hairless skin areas such as fingertips and soles of the feet.
  • Pacinian corpuscles are the large egg-shaped receptors found scattered deep in the dermis and monitoring vibration due to pressure. It allows detecting different textures, temperatures, hardness, and pain.
  • Ruffini endings which lie in the dermis respond to continuous pressure.
  • Krause end bulbs are thermoreceptors that sense temperature.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

Question 31.
Describe the structure of the receptor involved with a diagram.
Answer:

  • Taste buds are flask-shaped. There are two major types.
  • Gustatory epithelial cells or taste cells.
  • Basal epithelial cells or repairing cells.
  • Long micro villi called gustatory hairs project from the tip of the gustatory cells and extends through a taste pore to the surface of the epithelium.
  • Gustatory hairs are tire sensitive portion of the gustatory cells and they have sensory dendrites which send the signal to the brain.
  • The basal cells that act as stem cells divide and differentiate into new gustatory cells.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination 31

Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions

Tamilnadu State Board New Syllabus Samacheer Kalvi 11th Chemistry Guide Pdf Chapter 12 Basic Concepts of Organic Reactions Text Book Back Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 11th Chemistry Solutions Chapter 12 Basic Concepts of Organic Reactions

11th Chemistry Guide Basic Concepts of Organic Reactions Text Book Back Questions and Answers

Textbook Evaluation:

I. Choose the best answer:

Question 1.
For the following reactions
(A) CH3CH2CH2Br + KOH → CH3 – CH = CH2 + KBr + H2O

(B) (CH3)3CBr + KOH → (CH3)3COH + KBr

(C) Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 1
Which of the following statement is correct?
a) (A) is elimination, (B) and (C) are substitution
b) (A) is substitution, (B) and (C) are elimination
c) (A) and (B) are elimination and (C) is addition reaction
d) (A) is elimination, (B) is substitution and (C) is addition reaction
Answer:
d) (A) is elimination, (B) is substitution and (C) is addition reaction

Question 2.
What is the hybridisation state of benzyl carbonium ion?
a) sp2
b) spd2
c) sp3
d) sp2d
Answer:
a) sp2

Question 3.
Decreasing order of nucleophilicity is
a) OH > NH2 > -OCH3 > RNH2
b) NH2 > OH > -OCH3 > RNH2
c) NH2 > CH3O > OH > RNH2
d) CH3O > NH2 > OH > RNH2
Answer:
b) NH2 > OH > -OCH3 > RNH2

Question 4.
Which of the following species is not electrophilic in nature?
a) Cl+
b) BH3
c) H3O+
d) +NO2
Answer:
c) H3O+

Question 5.
Homolytic fission of covalent bond leads to the formation of
a) electrophile
b) nucleophile
c) carbocation
d) free radical
Answer:
d) free radical

Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions

Question 6.
Hyper conjucation is also known as
a) no bond resonance
b) Baker – nathan effect
c) both (a) and (b)
d) none of these
Answer:
c) both (a) and (b)

Question 7.
Which of the group has highest + I effect?
a) CH3
b) CH3 – CH2
c) (CH3)2 – CH-
d) (CH3)3 – C –
Answer:
d) (CH3)3 – C –

Question 8.
Which of the following species does not exert a resonance effect?
a) C6H5OH
b) C6H5Cl
c) C6H5NH2
d) C6H5NH3
Answer:
d) C6H5NH3

Question 9.
– I effect is shown by
a) – Cl
b) – Br
c) both (a) and (b)
d) – CH3
Answer:
c) both (a) and (b)

Question 10.
Which of the following carbocation will be most stable?
a) Ph3+C –
b) CH3+CH2
c) (CH3)2+CH
d) CH2 = CH – +CH2
Answer:
d) CH2 = CH – +CH2

Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions

Question 11.
Assertion:
Tertiary Carbocations are generally formed more easily than primary Carbocations ions.
Reason:
Hyper conjucation as well as inductive effect due to additional alkyl group stabilize tertiary carbonium ions.
a) both assertion and reason are true and reason is the correct explanation of assertion.
b) both assertion and reason are true but reason is not the correct explanation of assertion.
c) assertion is true but reason is false.
d) both assertion and reason are false.
Answer:
a) both assertion and reason are true and reason is the correct explanation of assertion.

Question 12.
Heterolytic fission of C – Br bond results in the formation of
a) free radical
b) Carbanion
c) Carbocation
d) Carbanion and Carbocation
Answer:
d) Carbanion and Carbocation

Question 13.
Which of the following represent a set of nucleophiles?
a) BF3, H2O, NH2-
b) AlCl3, BF3, NH3
c) CN, RCH2, ROH
d) H+, RNH3+, :CCl2
Answer:
c) CN, RCH2, ROH

Question 14.
Which of the following species does not acts as a nucleophile?
a) ROH
b) ROR
c) PCl3
d) BF3
Answer:
d) BF3

Question 15.
The geometrical shape of carbocation is
a) Linear
b) tetrahedral
c) Planar
d) Pyramidal
Answer:
c) Planar

Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions

II. Write brief answer to the following questions:

Question 16.
Write short notes on
a) Resonance
b) Hyper Conjugation
Answer:
a) Resonance (or) Mesomeric effect:
The resonance is a chemical phenomenon which is observed in certain organic compounds possessing double bonds at a suitable position. Certain organic compounds can be represented by more than one structure and they differ only in the position of bonding and lone pair of electrons. Such structures are called resonance structures (canonical structures) and this phenomenon is called resonance. This phenomenon is also called mesomerism or mesomeric effect.

For example, the structure of aromatic compounds such as benzene and conjugated systems like 1,3 – butadiene cannot be represented by a single structure, and their, observed properties can be explained on the basis of a resonance hybrid.

In 1,3 butadiene, it is expected that the bond between C1 – C2 and C3 – C4 should be shorter than that of C2 – C3, but the observed bond lengths are of same. This property cannot be explained by a simple structure in which two n bonds localised between C1 – C2 and C3 – C4. Actually, the n electrons are delocalised as shown below.

Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 2

The resonating structures are called canonical forms and the actual structure lies between these three resonating structures, and is called a resonance hybrid. The resonance hybrid is represented as below.

Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 3

Similar to the other electron displacement effect, mesomeric effect is also classified into positive mesomeric effect (+M or +R) and negative mesomeric effect (-M or -R) based on the nature of the functional group present adjacent to the multiple bond.

b) Hyper Conjugation:
The delocalisation of electrons of a bond is called as hyperconjugation. It is a special stabilising effect that results due to the interaction of electrons of a σ -bond (usually C – H or C – C) with the adjacent, empty non-bonding p-orbital or an anti¬bonding σ* or π*-orbitals resulting in an extended molecular orbital. Unlike the electromeric effect, hyper conjugation is a permanent effect.

It requires an α-CH group or a lone pair on atom-like N, O adjacent to a π bond (sp2 hybrid carbon). It occurs by the overlapping of the σ-bonding orbital or the orbital containing a lone pair with the adjacent π-orbital or p-orbital.

Example:
In propene, the σ -electrons of C-H bond of methyl group can be delocalised into the π -orbital of doubly bonded carbonas represented below.

Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 4

In the above structure the sigma bond is involved in resonance and breaks in order to supply electrons for delocalization giving rise to 3 new canonical forms. In the contributing canonical structures: (Il), (III) & (IV) of propene, there is no bond between an α-carbon and one of the hydrogen atoms. Hence the hyperconjugation is also known as “no bond resonance” or “Baker Nathan effect”. The structures (II), (III) & (IV) are polar in nature.

Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions

Question 17.
What are electrophiles and nucleophiles? Give suitable examples for each.
Answer:
Electrophiles:
Electrophiles are reagents that are attracted towards negative charge or electron-rich center. They are either positively charged ions or electron-deficient neutral molecules.
Example:
CO2, AlCl3, BF3, FeCl3, NO+, NO+2,, etc.

Nucleophiles:
Nucleophiles are reagents that has high affinity for electropositive centers. They possess an atom that has an unshared pair of electrons. They are usually negatively charged ions or electron-rich neutral molecules.
Example.
NH3, R-NH2, R-SH, H2O, R-OH, CN. OH etc.

Question 18.
Show the heterolysis of covalent bond by using curved arrow notation and complete the following equations. Identify the nucelophile in each case.
i) CH3 – Br + KOH →
ii) CH3 – O – CH3 + HI →
Answer:
(i) CH3 – Br + KOH →
CH3 – Br + KQH → CH3OH + KBr
Nucleophile is : OH

ii) CH3 – O – CH3 + HI →
H            I
CH3 – O – CH3 + HI → CH3OH + CH3 I
Nucleophile is : I

Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions

Question 19.
Explain inductive effect with suitable example.
Answer:
Inductive effect is defined as the change in the polarisation of a covalent bond due to the presence of adjacent bonds, atoms or groups in the molecule. This is a permanent phenomenon.

Let us explain the inductive effect by considering ethane and ethylchloride as examples. The C-C bond in ethane is non polar while the C-C bond in ethyl chloride is polar. We know that chlorine is more electronegative than carbon, and hence it attracts the shared pair of electron between C-Cl in ethyl chloride towards itself. This develops a slight negative charge on chlorine and a slight positive charge on carbon to which chlorine is attached.

To compensate for it, the C1 draws the shared pair of electrons between itself and C2 This polarisation effect is called the inductive effect. This effect is greatest for the adjacent bonds, but they also are felt farther away. However, the magnitude of the charge separation decreases rapidly, as we move away from C2 and is observed maximum for 2 carbons and almost insignificant after 4 bonds from the active group.
Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 5

It is important to note that the inductive effect does not transfer electrons from one atom to another but the displacement effect is permanent. The inductive effect represents the ability of a particular atom or a group to either withdraw or donate electron density to the attached carbon. Based on this ability the substituents are classified as +I groups and -I groups. Their ability to release or withdraw the electron through sigma covalent bond is called +I effect and -I effect respectively.

Highly electronegative atoms and atoms of groups which are cany a positive charge are electron-withdrawing or-I group.
Example :
-F , -Cl, -COOH, -NO2 NH2

Higher the electronegativity of the substituent, greater is the -I effect. The order of the -I effect of some groups are given below.
NH3 > NO2 > CN > SO3H > CHO > CO > COOH > COCl > CONH2 > F > Cl > Br > I > OH > OR > NH2 > C6H5 > H

Highly electropositive atoms and atoms are groups which carry a negative charge are electron-donating or +1 groups.
Example:
Alkali metals, alkyl groups such as methyl, ethyl, negatively charged groups such as CH3O, C2H5O, COO etc.

The lesser the electronegativity of the elements, the greater is the +1 effect. The relative order of +1 effect of some alkyl groups is given below.
-C(CH3)3 > -CH(CH3)2 > -CH2CH3 > -CH3

Question 20.
Explain electromeric effect with suitable example.
Answer:
Electromeric is a temporary effect which operates in unsaturated compounds (containing > C = C <, > C = 0, etc…) in the presence of an attacking reagent.
Let us consider two different compounds.
(i) compounds containing carbonyl group ( > C = O)
(ii) unsaturated compounds such as alkenes ( > C = C < )

When a nucleophile approaches the carbonyl compound, the n electrons between C and O is instantaneously shifted to the more electronegative oxygen. This makes the carbon electron-deficient and thus facilitating the formation of a new bond between the incoming nucleophile and the carbonyl carbon atom.
Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 6

On the other hand when an electrophile such as H+ approaches an alkene molecule, the π electrons are instantaneously shifted to the electrophile and a new bond is formed between carbon and hydrogen. This makes the other carbon electron-deficient and hence it acquires a positive charge.

Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 7

The electrometric effect, is denoted as E effect. Like the inductive effect, the electrometric effect is also classified as + E and – E based on the direction in which the pair of electrons is transferred to form a new bond with the attacking agent.

Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 8

When the π electron is transferred towards the attacking reagent, it is called + E (positive electrometric) effect.

The addition of H+ to alkene as shown above is an example of +E effect.
When the n electron is transferred away from the attacking reagent, it is called, -E (negative electrometric) effect.
Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 9
The attack of CN on a carbonyl carbon, as shown above, is an example of – E effect.

Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions

Question 21.
Give examples for the following types of organic reactions
(i) β – elimination
(ii) Electrophilic substitution
Answer:
(i) β – elimination:
In this reaction two substituents are eliminated from the molecule, and a new C – C double bond is formed between the carbon atoms to which the eliminated atoms/groups are previously attached. Elimination reaction is always accompanied with change in hybridisation.
Example:
n – Propyl bromide on reaction with alcoholic KOH gives propene. In this reaction hydrogen and Br are eliminated.
Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 10

(ii) Electrophilic substitution:

Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 11
Here, Y+ is an electrophile.
Example :
Nitration of Benzene

Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 12

11th Chemistry Guide Basic Concepts of Organic Reactions Additional Questions and Answers

I. Choose the best answer:

Question 1.
In organic reactions, the reactant is called ______.
a) intermediate
b) product
c) substrate
d) by product
Answer:
c) substrate

Question 2.
Heterolysis of C – Cl bond produces
a) Two free radicals
b) Two carbonium ions
c) Two carbanions
d) One cation and one anion
Answer:
d) One cation and one anion

Question 3.
Which one of the following is an example for free radical initiators?
(a) Benzoyl peroxide
(b) Benzyl alcohol
(c) Benzyl acetate
(d) Benzaldehyde.
Answer:
(a) Benzoyl peroxide.

Question 4.
Removal of hydride ion from a methane molecule will give a
a) Methyl radical
b) Carbonium ion
c) Carbanion
d) Methyl group
Answer:
b) Carbonium ion

Question 5.
The shape of carbonium ion is
a) Planar
b) Linear
c) Pyramidal
d) Tetrahedral
Answer:
a) Planar

Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions

Question 6.
Which of the following is correct order of the stability of carbocations?
(a) +CH3 > +CH2 CH3> +CH(CH3)2 > +C(CH3)3
(b) +CH2CH3 > +CH3 >+ CH(CH3)2 > +C(CH3)3
(c) +C(CH3)3 > +CH(CH3)2 >+CH2CH3CH3
(d) +CH(CH3)2 > +CH3 > +CH2CH3 > +C(CH3)3
Answer:
(c) +C(CH3)3 > +CH(CH3)2 >+CH2CH3CH3

Question 7.
The reaction, (CH3)3C – Br -» (CH3)3 C+ + Br is an example of
a) Homolytic fission
b) Heterolytic fission
c) Cracking
d) All the above
Answer:
b) Heterolytic fission

Question 8.
Which one of the following is not electrophile’?
(a) NH3
(b) AlCl3
(c) FeCl3
(d) R-X
Answer:
(a) NH3

Question 9.
Which of the following species is paramagnetic
a) A carbaonium ion
b) A free radical
c) A carbanion
d) All of these
Answer:
b) A free radical

Question 10.
Which one of the following are positively charged electrophiles?
(a) CO2
(b) AlCl3
(c) BF3
(d) RX
Answer:
(d) RX

Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions

Question 11.
Among the following the true property about
Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 13 is
a) non – planar
b) C+ is sp2 – hybridized
c) Electrophile can attack on C+
d) Does not undergo hydrolysis
Answer:
b) C+ is sp2 – hybridized

Question 12.
Which one of the following species has a tendency to show-I effect?
(a) -CH3
(b) -CH2-CH3
(c) -CH(CH3)2
(d) -C6H5
Answer:
(d) -C6H5

Question 13.
Which of the following statements are correct for nucleophile?
a) All negatively charged species are nucleophiles
b) Nucleophiles are Lewis bases
c) Alkenes, alkynes, benzene and pyrrole are nucleophiles
d) All are correct
Answer:
d) All are correct

Question 14.
Which one of the following statement is not correct for electrophile?
a) Electron deficient species are electrophiles
b) Electrophiles are Lewis acids
c) All positively charged species are electrophiles
d) AlCl3 and SO3 are electrophiles
Answer:
c) All positively charged species are electrophiles

Question 15.
Electrophiles are
a) Lewis bases
b) Lewis acids
c) Amphoteric
d) All of these
Answer:
b) Lewis acids

Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions

Question 16.
Pick out the correct order of acid strength.
(a) CH3-CH2-COOH > CH3COOH > CH2CICOOH
(b) CH3COOH > CH3-CH2-COOH >CH2CICOOH
(c) CH2ClCOOH > CH3COOH > CH3-CH2-COOH
(d) CH2ClCOOH > CH3-CH2-COOH > CH3COOH
Answer:
(c) CH2ClCOOH > CH3COOH > CH3—CH2-COOH

Question 17.
Nucleophiles are
a) Electron loving
b) Electron hating
c) Nucleus loving
d) Nucleus hating
Answer:
c) Nucleus loving

Question 18.
Which of the following statement is false about an electrophile?
a) Electron – deficient species
b) An acidic reagent
c) A reagent which attacks an electron-deficient site in a molecule
d) A species which seeks a pair of electrons
Answer:
c) A reagent which attacks an electron-deficient site in a molecule

Question 19.
Which one of the following electrophiles used for nitration of benzene?
(a) \({ Br }^{ \oplus }\)
(b) \({ { NO }_{ 2 }^{ \ominus } }\)
(c) -NH2
(d) \({ NO }^{ \ominus }\)
Answer:
(b) \({ { NO }_{ 2 }^{ \ominus } }\)

Question 20.
Ammonia molecule is
a) A nucleophile
b) An electron-deficient
c) A electrophile
d) An acid
Answer:
a) A nucleophile

Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions

Question 21.
Methyl carbanion is
a) Electrophile
b) Lewis acid
c) Both (a) and (b)
d) Nucleophile
Answer:
d) Nucelophile

Question 22.
Which of the following statements is correct about the inductive effect?
a) Implies the transfer of lone pair of electrons from more electronegative atom to lesser electronegative atom in a molecule.
b) Implies the transfer to lone pair of electrons from lesser electronegative atom to the more electronegative atom in a molecule
c) Increases with increase in distance
d) Implies the atoms ability to cause bond polarization
Answer:
d) Implies the atoms ability to cause bond polarization

Question 23.
The displacement of electrons in a multiple bond in the presence of attacking reagent is called
a) inductive effect
b) electromeric effect
c) resonance
d) Hyper-conjugation
Answer:
b) electromeric effect

Question 24.
The electromeric effect in organic compounds is a
a) Temporary effect
b) Permanent effect
c) Temporary or permanent effect
d) All of the above
Answer:
a) Temporary effect

Question 25.
Which of the following is not the correct condition for resonance?
a) The positions of all the atomic nuclei in the resonating structures may be differ
b) The resonating structures must have the same number of unpaired or paired electrons
c) The molecules exhibiting resonance must be planar in nature
d) The resonating structures must have nearly the same energies
Answer:
a) The positions of all the atomic nuclei in the resonating structures may be differ

Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions

Question 26.
Resonance is due to ______.
a) delocalization of sigma electrons
b) migration of H atoms
c) migration of proton
d) delocalization of pi electrons
Answer:
d) delocalization of pi electrons

Question 27.
Resonance in benzene is accompanied by delocalization of n – electrons. Each n electron is attached with
a) 4 carbons
b) 2 carbons
c) 3 carbons
d) 6 carbons
Answer:
d) 6 carbons

Question 28.
Reaction mechanism describes
a) Sequential account of each step describing the details of electron movement
b) energy changes during bond breaking and bond formation
c) kinetics of the reaction
d) all of these
Answer:
d) all of these

Question 29.
Substitution reaction may be
a) Free radical substitution
b) Nucleophilic substitution
c) Electrophilic substitution
d) All are correct
Answer:
d) All are correct

Question 30.
CH3 – CH2 – X + KOH(alc) → CH2 = CH2 + KX + H2O is
a) addition reaction
b) substitution reaction
c) elimination reaction
d) molecular rearrangement
Answer:
c) elimination reaction

Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions

Question 31.
CH4 + Cl2 Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 14 CH3Cl + HCl is an example
for
a) free radical substitution reaction
b) electrophilic substitution reaction
c) nucleophile substitution reaction
d) nueclophilic addition reaction
Answer:
a) free radical substitution reaction

Question 32.
C6H6 + 3 Cl2 Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 14 C6H6Cl
a) free radical substitution reaction
b) electrophilic addition reaction
c) free radical addition reaction
d) nueclophilic addition reaction
Answer:
c) free radical addition reaction

Question 33.
Which one of the following orders is correct regarding the – I effect of the substituents?
a) – NR2 < – OR > – F
b) -NR2 > – OR > – F
c) -NR2 < – OR< – F
d) -NR2 > – OR < – F
Answer:
c) -NR2 < – OR< – F

Question 34.
Decreasing – I power of given groups is
(1) -CN
(2) -NO2
(3) – NH3+
(4) -F
a) 2 > 1 > 4 > 3
b) 2 > 3 > 4 > 1
c) 3 > 2 > 4 > 1
d) 3 > 2 > 1 > 4
Answer:
d) 3 > 2 > 1 > 4

Question 35.
Which of the following belongs to – I group?
a) – C6H5
b) – CH3
c) – CH2CH3
d) – C (CH3)3
Answer:
a) – C6H5

Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions

Question 36.
Which of the following functional group shows + R effect?
a) – CHO
b) – NO2
c) -CN
d) – NR2
Answer:
d) – NR2

Question 37.
Hyper conjugation is
a) σ – π conjugation
b) Due to delocalization of σ and π bonds
c) No bond resonance
d) All of these
Answer:
d) All of these

Question 38.
+ R power of the given groups
(1) -O
(2) – NH2
(3) – OH
(4) – NHCOCH3 in decreasing order is
a) 1 > 2 > 3 > 4
b) 4 > 3 > 2 > 1
c) 1 > 3 > 2 > 4
d) 1 > 4 > 3 > 2
Answer:
a) 1 > 2 > 3 > 4

Question 39.
In pyridine:
Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 15
Number of conjugated electrons are:
a) 6
b) 8
c) Zero
d) 5
Answer:
a) 6

Question 40.
In hyperconjugation, the atom involved is
a) β – H atom
b) α – H atom
c) γ – H atom
d) All
Answer:
b) α – H atom

Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions

Question 41.
Hyper conjugation involves overlap of the following orbtials
a) σ – σ
b) σ – p
c) p – p
d) π – π
Answer:
b) σ – p

Question 42.
+ I effect is shown by
a) – NO2
b) – Cl
c) – Br
d) – CH3
Answer:
d) – CH3

Question 43.
Zero inductive effect is exerted by
a) C6H5
b) – H
c) CH3
d) – Cl
Answer:
b) – H

Question 44.
Hyper conjugation is most useful for stabilizing which of the following carbocations?
a) neo – Pentyl
b) tert – Butyl
c) iso – Propyl
d) Ethyl
Answer:
b) tert – Butyl

Question 45.
Hyper conjugation phenomenon is possible in
a) H2C = CH2
b) CH3CH2 – CH = CH2
c) C6H5CH = CH2
d) (CH3)3C – CH = CH2
Answer:
b) CH3CH2 – CH = CH2

Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions

Question 46.
Among the following carbocations which is more stable
a) (C6H5)3C+
b) Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 16
c) Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 17
d) Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 18
Answer:
a) (C6H5)3C+

Question 47.
The compound which gives the most stable carbonium ion on dehydration
a) Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 19
b) Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 20
c) CH3 – CH2 – CH2 – CH2OH
d) Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 21
Answer:
b) Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 20

Question 48.
Which carbocation is more stable?
Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 22
Answer:
a) Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 23

Question 49.
Arrange the following groups in order of decreasing – R (Or – M) power
(1) NO2
(2) SO3H
(3) CF3
(4) CHO
a) 1 > 3 > 2 > 4
b) 1 > 2 > 3 > 4
c) 1 > 4 > 3 > 2
d)4 > 3 > 2 > 1
Answer:
a) 1 > 3 > 2 > 4

Question 50.
The reaction intermediate produced by homolytic cleavage of bond is called
a) carbocations
b) carbanions
c) free radicals
d) carbenes
Answer:
c) free radicals

Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions

Question 51.
Most stable carbocation is
a) CH3+CH2
b) +CH2CHCl2
c) +CH2CH2Cl
d) +CH2 – CH2NO2
Answer:
a) CH3+CH2

Question 52.
Carbocation is a reaction intermediate in which of the following reactions
a) E1 reactions
b) Electrophilic addition reactions of alkenes and alkynes
c) SN1 reactions
d) All of the above
Answer:
d) All of the above

Question 53.
Halogenation of an alkane takes place through the intermediate
a) Carbocation
b) carbanion
c) carbon free radical
d) carbene
Answer:
c) carbon free radical

Question 54.
Which free radical is the most stable?
Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 24
Answer:
a) Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 25

Question 55.
The most stable carbonium ion is
a) Methyl carbonium ion
b) Primary carbonium ion
c) Secondary carbonium ion
d) Tertiary carbonium ion
Answer:
d) Tertiary carbonium ion

Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions

Question 56.
Stability of which intermediate is not govern by hyperconjugation?
a) Carbon cation
b) carbon anion
c) carbon-free radical
d) carboniumion
Answer:
b) carbon anion

Question 57.
Which of the following is an electrophilic reagent?
a) H2O
b) OH
c) NO2+
d) All of these
Answer:
c) NO2+

Question 58.
CH2 = CH2 + Br2 → CH2Br – CH2Br is an example for
a) addition reaction
b) substitution reaction
c) elimination reaction
d) molecular rearrangement
Answer:
a) addition reaction

Question 59.
R – X + OH(aq) → R – OH + X+(aq) is an example for
a) addition reaction
b) substitution reaction
c) elimination reaction
d) molecular rearrangement
Answer:
b) substitution reaction

Question 60.
C6H6 + Cl2 Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 26 C6H5Cl + HC1 is an example for
a) Free radical substitution reaction
b) Electrophilic substitution reaction
c) Nucleophilic addition reaction
d) Nucelophilic substitution reaction
Answer:
b) Electrophilic substitution reaction

Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions

Question 61.
Alkenes readily undergo
a) Substitution reactions
b) Addition reactions
c) Elimination reactions
d) Rearrangement reactions
Answer:
b) Addition reactions

Question 62.
Nitration of benzene is
a) nucleophilic substitution
b) nucleophilic addition
c) electrophilic substitution
d) free radical substitution
Answer:
c) electrophilic substitution

Question 63.
The reaction (CH3)3C – Br Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 27 (CH3)3 C – OH is
a) elimination reaction
b) substitution reaction
c) free radical reaction
d) displacement reaction
Answer:
b) substitution reaction

Question 64.
Inductive effect involves
a) displacement of σ – electrons
b) delocalization of π – electrons
c) delocalization of σ – electrons
d) displacement of π – electrons
Answer:
b) delocalization of π – electrons

Question 65.
Compound which shows positive mesomeric effect
a) H2C = CH – Cl
b) C6H5 – NO2
c) H2C = CH – CH2Cl
d) both b & c
Answer:
a) H2C = CH – Cl

Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions

Question 66.
The stability order, in the following carbocations,
CH3CH2+ (I), (CH3)2 +CH (II), (CH3)3 C+ (III), +CH3 (IV)
a) I > IV > III > II
b) I > II > III > IV
c) III > IV > I > II
d) III > II > I > IV
Answer:
d) III > II > I > IV

Question 67.
Which is most stable carbocation?
a) n – propyl cation
b) iso – propyl cation
c) Ethyl cation
d) Triphenylmethyl cation
Answer:
d) Triphenylmethyl cation

Question 68.
Which one of the following carbanions is least stable?
a) CH3CH2
b) HC ≡ C
c) (C6H5)3C
d) (CH3)3C
Answer:
d) (CH3)3C

Question 69.
Among the following, the strongest nucleophile is
a) C2H5SH
b) CH3COO
c) CH3NH2
d) NCCH2
Answer:
a) C2H5SH

Question 70.
Which of the following is least reactive in a nucleophile substitution reaction?
a) (CH3)3C – Cl
b) CH2 = CHCl
c) CH3CH2Cl
d) CH2 = CHCH2Cl
Answer:
b) CH2 = CHCl

Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions

II. Very short question and answers (2 Marks):

Question 1.
What are organic reactions?
Answer:
The substrate is an organic molecule that reacts with a reagent, which may be an organic, inorganic, or any agent like heat, photon, etc, that brings about the chemical change to form a product, this is known as organic reactions.

Question 2.
What is the Positive Mesomeric effect? Give example.
Answer:
A positive resonance effect occurs, when the electrons move away from substituents attached to the conjugated system. It occurs, if the electron releasing substituents are attached to the conjugated system. In such cases, the attached group has a tendency to release electrons through resonance. These electron releasing groups are usually denoted as +R or +M groups.
Example:
– OH , – SH , – OR , – SR, – NH2, – O – etc…

Question 3.
Mention the types of fission of a covalent bond?
Answer:
There are three types of fission of a covalent bond. They are,

  • Homolytic cleavage
  • Heterolytic cleavage

Question 4.
Explain hyper conjugate effect of vinyl chloride molecule.
Answer:
Hyper conjugation effect is also observed when atoms/groups having lone pair of electrons are attached by a single bond, and in conjugation with a π bond. The lone pair of electrons enters into resonance and displaces π electrons resulting in more than one structure.
Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 28

Question 5.
What are the types of substitution reactions?
Answer:
In this reaction, an atom or a group of atoms attached to a carbon atom is replaced by a new atom or a group of atoms. Based on the nature of the attacking reagent, these reactions can be classified as

  • Nucleophilic substitution
  • Electrophilic substitution
  • Free radical substitution

Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions

Question 6.
Explain free radical substitution reaction with the suitable example.
Answer:
Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 29
Aliphatic electrophilic substitution
A general aliphatic electrophilic substitution is represented as
Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 30

Question 7.
Explain Nucleophilic Addition reaction with suitable example.
Answer:
Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 31
Example:
Addition of HCN to acetaldehyde
Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 32

Question 8.
Explain free radical addition reaction with suitable example.
Answer:
A general free radical addition reaction can be represented as below.
Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 33
Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 34
In the above reaction, Benzoyl perioxide acts as an radial initiator. The mechanism involves free radicals.

Question 9.
Write a note on Functional Group inter conversion.
Answer:
Organic synthesis involves functional group inter conversions. A particular functional group can be converted into other functional group by reacting it with suitable reagents. For example, The carboxylic acid group (-COOH) presents in organic acids can be transformed to a variety of other functional group such as – CH2-OH, – CONH2, – COCl by treating the acid with LiAlH4, NH3, and SOCl2 respectively.

Question 10.
Differentiate the carbocation and carbanion.
Answer:
Carbocation:

  • In a carbocation carbon-bearing positive charge.
  • Carbon bearing positive charge has sp2 hybridization.
  • It has a planar structure.
  • Example: CH3+ (CH3)2\({ C }^{ \ominus }\)H, (CH3)3C+ etc.

Carbanion:

  • In a carbanion carbon bearing negative charge.
  • Carbon bearing negative charge has sp3 hybridization.
  • It has a pyramidal structure.
  • Example: CH3–\({ C }^{ \ominus }\)H2, CH3-CHO, (CH3)2\({ C }^{ \ominus }\)H etc.

Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions

III. Short answer questions (3 Marks):

Question 1.
Explain the hybridization of carbon in carbocation.
Answer:
In a carbocation, the carbon-bearing positive charge is sp2 hybridized and hence it has a planar structure. In the reaction involving such a carbocation, the attack of a negatively charged species (nucleophiles) take place on either side of the carbocation as shown below.
Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 35
Shape of carbocation

The carbanions are generally pyramidal in shape and the lone pair occupies one of the sp3 hybridized orbitais. An alkyl free radical may be either pyramidal or planar.
Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 36
Shape of carbanion

Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 37
The shape of Carbon radical

Question 2.
Write three types of electron movement in organic reaction.
Answer:

  • lone pair becomes a bonding pair.
  • bonding pair becomes a lone pair.
  • a bond breaks and becomes another bond.

Type: 1
A lone pair to a bonding pair
Example:
Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 38

Type: 2
A bonding pair to a lone pair
Example:
Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 39

Type: 3
A bonding pair to an another bonding pair
Example:
Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 40

Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions

Question 3.
Explain hyper conjugate effect of acrylonitrile.
Answer:
When electronegative atoms or group of atoms are in conjugation with a π – bond,they pull π – electrons from the multiple bond. In case of carbocations, greater the number of alky groups attached to the carbon bearing positive charge, greater is number of the hyper conjucate structure. thus the stability of various carbocations decreases in the order :
3° Carbocation > 2° Carbocation > 1° Carbocation.

Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 41

Question 4.
What are functional group interconversions?
Answer:
Organic synthesis involves functional group interconversions. A particular functional group can be converted into other functional groups by reacting it with suitable reagents. For example, the carboxylic acid group (-COOH) present in organic acids can be transformed into -COCl by treating the acid with SOCl2 reagent.

Question 5.
Explain nucleophilc substituion reaction with suitable example.
Answer:
This reaction can be represented as
Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 42
Here Y is the incoming nuclophile or and attacking species and x is the leaving group.

Example:
Hydrolysis of alkyl halides by aqueous KOH.
CH3Br  Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 43 CH3OH + Br
Aliphatic nucleophilic substitution reactions take place either by SN1 or SN2 mechanism.

Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions

Question 6.
Explain Electrophilic Addition Reaction with suitable example.
Answer:
A general electrophilic addition reaction can be represented as below.
Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 44
Example:
Bromination of alkene to give bromo alkane
Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 45

Question 7.
What are oxidation and reduction reactions? Give suitable example.
Answer:
Many oxidation and reduction reactions of organic compounds fall into one of the four types of reaction that we already discussed but others do not. Most of the oxidation reaction of organic compounds involves gain of oxygen or loss of hydrogen Reduction involves gain of hydrogen and loss of oxygen.
Example:
Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 46

Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 47

Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions

IV. Long answer questions (5 Marks):

Question 1.
Explain different types of Fission of a covalent bond.
Answer:
All organic molecules contain covalent bonds which are formed by the mutual sharing of electrons between atoms. These covalent bonds break in two different ways, namely homolytic cleavage (symmetrical splitting) and heterolytic cleavage (unsymmetrical splitting). The cleavage of a bond in the substrate is influenced by the nature of the reagent (attacking agent).

Homolytic Cleavage:
Homolytic cleavage is the process in which a covalent bond breaks symmetrically in such way that each of the bonded atoms retains one electron. It is denoted by a half headed arrow (fish hook arrow). This type of cleavage occurs under high temperature or in the presence of UV light in a compound containing non polar covalent bond formed between atoms of similar electronegativity.

In such molecules, the cleavage of bonds results into free radicals. They are short lived and are highly reactive. The type of reagents that promote holmolytic cleavage in substrate are called as free radical initiators. For example Azobisisobutyronitile (AIBN) and peroxides such as benzoyl peroxide are used as free radical initiators in polymerisation reactions.

Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 48

As a free radical with an unpaired electron is neutral and unstable, it has a tendency to gain an electron to attain stability. Organic reactions involve homolytic fission of C – C bonds to form alkyl free radicals. The stability of alkyl free radicals is in the following order:
C(CH3)3 > CH(CH3)2 > CH2CH3 > CH3

Heterolytic Cleavage:
Heterolytic cleavage is the process in which a covalent bond breaks unsymmetrically such that one of the bonded atoms retains the bond pair of electrons. It results in the formation of a cation and an anion. Of the two bonded atoms, the most electronegative atom becomes the anion and the other atom becomes the cation. The cleavage is denoted by a curved arrow pointing towards the more electronegative atom.

For example, in tert-butyl bromide, the C – Br bond is polar as bromine is more electronegative than carbon. The bonding electrons of the C – Br bond are attracted more by bromine than carbon. Hence, the C – Br undergoes heterolytic cleavage to form a tert-butyl cation during hydrolysis.

Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 49

Let us consider the cleavage in a carbon-hydrogen (C-H) bond of aldehydes or ketones We know that the carbon is more electronegative than hydrogen and hence the heterolytic cleavage of C-H bonds results in the formation of carbanion (carbon bears a negative charge). For example in aldol condensation the OH- ion abstracts a a-hydrogen from the aldehyde, which leads to the formation of the below mentioned carbanion.

Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 50

Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions

Question 2.
Explain the acidic nature of carboxylic acid.
Answer:
When a halogen atom is attached to the carbon which is nearer to the carboxylic acid group, its -I effect withdraws the bonded electrons towards itself and makes the ionisation of H easy. The acidity of various chioro acetic acid is in the following order. The strength of the acid increases with increase in the -J effect of the group attached to the carboxyl group.

Trichioro acetic acid > Dichloro acetic acid > Chloro acetic acid > acetic acid.
Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 51

Similarly, the following order of acidity in the carboxylic acids is due to the +I effect of alkyl group.
Samacheer Kalvi 11th Chemistry Guide Chapter 12 Basic Concepts of Organic Reactions 52

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Tamilnadu State Board New Syllabus Samacheer Kalvi 11th Bio Zoology Guide Pdf Chapter 11 Chemical Coordination and Integration Text Book Back Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 11th Bio Zoology Guide Chapter Chapter 11 Chemical Coordination and Integration

11th Bio Zoology Guide Chemical Coordination and Integration Text Book Back Questions and Answers

Part I

Question 1.
The maintenance of a constant internal environment is referred as
a) Regulation
b) homeostasis
c) Co-ordination
d) hormonal control
Answer:
b) homeostasis

Question 2.
Which of the following are exclusive endocrine glands?
a) Thymus and testis
b) adrenal and ovary
c) parathyroid and adrenal
d) pancreas and parathyroid
Answer:
c) parathyroid and adrenal

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 3.
Which of the following hormone is not secreted under the influence of the pituitary gland?
a) thyroxine
b) insulin
c) oestrogen
d) glucocorticoids
Answer:
b) insulin

Question 4.
Spermatogenesis in mammalian testes is controlled by
a) Luteinising hormone
b) Follicle-stimulating Hormone
c) FSH and prolactin
d) GH and prolactin
Answer:
b) Follicle-stimulating Hormone

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 5.
Serum calcium level is regulated by
a) Thyroxine
b) FSH
c) Pancreas
d) Thyroid and parathyroid
Answer:
d) Thyroid and parathyroid

Question 6.
Iodised salt is essential to prevent
a) rickets
b) scurvy
c) goiter
d) acromegaly
Answer:
c) goiter

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 7.
Which of the following gland is related to immunity?
a) Pineal gland
b) adrenal gland
c) thymus
d) parathyroid gland
Answer:
c) thymus

Question 8.
Which of the following statement about sex hormones is correct?
a) Testosterone is produced by Leydig ceils under the influence of the luteinizing hormone
b) Progesterone is secreted by corpus luteum and softens pelvic ligaments during childbirth
c) Oestrogen is secreted by both sertoli cells and corpus luteum
d) Progesterone produced by corpus luteum is biologically different from the one produced by the placenta.
Answer:
a) Testosterone is produced by Leydig cells under the influence of luteinizing hormone

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 9.
Hypersecretion of GH in children leads to
a) Cretinism
b) Gigantism
c) Graves disease
d) Tetany
Answer:
b) Gigantism

Question 10.
A pregnant female delivers a baby who suffers from stunted growth, mental retardation, low intelligence quotient, and abnormal skin. This is the result of
a) Low secretion of growth hormone
b) Cancer of the thyroid gland
c) Over secretion of pars distalis
d) Deficiency of iodine in the diet
Answer:
a) Low secretion of growth hormone

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 11.
The structure which connects the hypothalamus with the anterior lobe of the pituitary gland is the
a) Dendrites of the neurohypophysis
b) Axons of neuro hypophysis
c) Bands of white fibers from the cerebellar region
d) Hypophysial portal system
Answer:
d) Hypophysial portal system

Question 12.
Comment on homeostasis.
Answer:

  • Maintenance of constant internal environment of the body by the different co-ordinating system.
  • The maintenance of the constant internal environment of the body is due to the functioning of the endocrine system and nervous system.
    Endocrine gland.

1. a) If the calcium level in the blood decreases the parathyroid gland secretes parathyroid hormones and increases the calcium level in the blood.
b) If there is more calcium in the blood the other hormone secreted by the parathyroid gland called calcitonin acts against the parathormone and reduces calcium level.

2. a) The adrenalin secreted by the adrenal gland in emergency increases heartbeat rate and blood pressure.
b) The other hormone secreted by the adrenal is nor-adrenalin which reduces heartbeat rate and blood pressure.

Nervous system:
1. a) The sympathetic nervous system at the time of shock induces tear glands to secrete tears,
b) The parasympathetic nerve at the time of shock and emotion reduces the tear secretion.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 13.
Which one of the following statement is correct
a) Calcitonin and thymosin are thyroid hormones
b) Pepsin and prolactin are secreted in the stomach
c) Secretin and rhodopsin are polypeptide hormones
d) Cortisol and aldosterone are steroid hormones
Answer:
d) Cortisol and aldosterone are steroid hormones

Question 14.
Which of the given option shows all wrong statements for thyroid gland Statements?
i) It inhibits the process of RBC formation
ii) It helps in the maintenance of water and electrolytes
iii) It’s more secretion can reduce blood pressure
iv) It stimulates osteoblast
(a) (i) and (ii)
(b) (iii) and (iv)
(c) (i) and (iv)
(d) (i) and (iii)
Answer:
(d) (i) and (iii)

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 15.
Hormones are known as a chemical messengers. Justify.
Answer:
Hormones are released into the blood stream and circulated as chemical signals. These act specifically on certain organs or tissues called target organs or tissues. These speed up or slow down or alter the activity of target tissues or organs. Hence they are known as chemaical messengers.

Question 16.
Write the role of t-estrogen in ovulation.
Answer:

  • Oestrogen hormones promote the growth of the ovarian follicle
  • While the follicles are growing it secretes the hormone oestrogen which in turn promotes the ovum to develop.
  • The shedding up of ovum at the Luteal phase takes place by the influence of the Luteinizing hormone.

Question 17.
Comment on Acini of the thyroid gland.
Answer:
The thyroid gland is a bilobed endocrine gland. Each lobe is made up of many lobules. The lobules consist of follicles called acini. Each acinus is lined with glandular, cuboidal, or squamous epithelial cells. The lumen of acinus is filled with colloid, a thick glycoprotein mixture consisting of thyroglobulin molecules.

Question 18.
Write the causes for diabetes mellitus and diabetes insipidus.
Answer:

  • Diabetes emeritus: If the insulin is not secreted sufficiently the liver and muscles are unable to convert the glucose into glycogen. As a result, more glucose enters into the bloodstream raising the blood sugar level leads to diabetes mellitus.
  • Diabetes Insipidus: The hormone antidiuretic hormone is secreted by the neurohypophysis, which promotes reabsorption of water and thus reduces the loss of water through urine ADH deficiency induces the production of large amounts of urine leads to diabetes insipidus.

Question 19.
Specify the symptoms of acromegaly.
Answer:
Acromegaly is caused due to excessive secretion of growth hormone in adults. The symptoms of acromegaly are an overgrowth of hand bones, feet bones, jawbones malfunctioning of gonads. enlargement of viscera, tongue, lungs, heart, liver, spleen, and endocrine glands like thyroid, or adrenal glands.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 20.
Write the symptoms of cretinism.
Answer:
Cretinism is caused due to hypothyroidism in infants. A cretin child shows the following symptoms:-

  1. Retarded skeletal growth.
  2. Absence of sexual maturity
  3. Retarded mental ability
  4. Thick and short limbs
  5. Thick wrinkled skin
  6. Bloated face
  7. Protruded enlarged tongue
  8. Low BMR, slow pulse rate, subnormal body temperature, and elevated blood cholesterol levels

Question 21.
Briefly explain the structure of the thyroid gland.
Answer:
The thyroid gland is butterfly-shaped, bilobed situated below the larynx on each side of the upper trachea. The two lobes are connected by a median tissue mass called isthmus. Each lobe is made up of many lobules. The lobules consist of follicles called acini. Each acinus is lined with glandular, cuboidal, or squamous epithelial cells.

The lumen of acini is filled with colloid, a thick glycoprotein mixture consisting of thyroglobulin molecules. The thyroid gland secretes Tri-iodothyronine (T,) and tetra-iodothyronine (T4) or thyroxine hormones. These are concerned with metabolism.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration 1

Question 22.
Name the layers of the adrenal cortex and mention their secretions?
Answer:
A pair of adrenal glands are located at the anterior end of the kidneys. Elence, they are called suprarenal glands. The outer region is called cortex and the inner region is medulla. The adrenal cortex has three distinct zones,

  1. Zona Glomerulosa
  2. Zona fasciculata
  3. Zona reticularis

1. Zona Glomerulosa:

  • It is the outer thin layer. It constitutes about 15% of the cortex.
  • It secretes mineralocorticoids.

2. Zona fasciculata:

  • It is the middle wide layer constituting about 15% of the adrenal cortex.
  • It secretes glucocorticoids such as cortisol, corticosterone and trace amounts of adrenal androgen and oestrogen.

3. Zona reticularis:

  • It is the inner zone of adrenal cortex.
  • It constitutes about 10% of adrenal cortex.
  • It constitutes about 10% of adrenal cortex.
  • It secretes the adrenal androgen, trace amount of oestrogen and glucocorticoids.

Question 23.
Differentiate hyperglycemia from hypoglycemia.
Answer:
Hyper glycemia:
Hyperglycemia is a condition in which there is increased blood glucose level, it may be due to the reduced secretion of insulin.

Hypo glycemia:
Hypoglycemia is a condition in which the blood glucose level decreases. It may be due to increased secretion of insulin thereby reducing blood glucose level.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 24.
Write the functions of (CCK)- Cholecystokinin.
Answer:
CholecystokininCholecystokinin is secreted by duodenum in response to the presence of fat and acid in the diet. It acts on the gall bladder to release bile into duodenum and stimulates the secretion of pancreatic enzymes and its discharge.

Question 25.
Growth hormone is important for normal growth. Justify the statement.
Answer:
Growth hormone promotes growth of all the tissues and metabolic process of the cell. The growth hormone stimulates the growth in the following ways

  • It influences the metabolism of carbohydrate proteins and lipids.
  • It increases the rate of protein biosynthesis.
  • It stimulates cartilage formation of chondrogenesis.
  • It stimulates bone formation osteogenesis.
  • It helps in the retention of minerals like nitrogen, potassium, phosphorous sodium in the body.
  • It increases the release of fatty acid from adipose tissue.
  • It decreases the rate of glucose utilization for energy by the cell, by which it conserves glucose for glucose-dependent tissues such as the brain.

Question 26.
The pineal gland is an endocrine gland, write its role.
Answer:
The pineal gland or epiphysis cerebri or conarium is located behind the third ventricle of the brain. It is formed of parenchymal cells and interstitial cells. It secretes the hormone, melatonin.

It plays a central role in the regulation of the circadian rhythm of our body and maintains a normal sleep-wake cycle. It also regulates the timing of the sexual maturation of gonads. It also influences metabolism, pigmentation, menstrual cycle and defence mechanism of our body.

Question 27.
Comment on the functions of adrenalin.
Answer:

  • Adrenalin increases liver glycogen breakdown into glucose and increases the release of fatty acids from fat cells.
  • During emergency, it increases heartbeat rate and blood pressure.
  • It stimulates the smooth muscles of cutaneous and visceral arteries to decrease blood flow.
  • It increases blood flow to the skeletal muscles thereby increases the metabolic rate of skeletal muscles cardiac muscles and nervous tissues.

Question 28.
Predict the effects of removal of the Pancreas from the human body.
Answer:
Pancreas is both exocrine and endocrine gland. It is located just below the stomach as a leaf-like structure. It secretes digestive enzymes and hormones like insulin and glucogon.

The digestive enzymes digest carbohydrates, proteins, and fats. Insulin and glucose regulate blood sugar levels. If pancreas is removed from the body, digestion and maintenance of blood sugar level get affected.

Question 29.
Enumerate the role of the kidney as an endocrine gland.
Answer:
Kidney has endocrine tissues which act as a partial endocrine gland. It secretes renin, erythropoietin, and calcitriol. Renin is secreted by juxtaglomerular cells. It increases blood pressure when angiotensin is formed in the blood.

Erythropoietin is also secreted by the juxtaglomerular cells of the kidney and stimulates erythropoiesis in the bone marrow. Calcitriol is secreted by proximal tubes of nephrons. It is an active form of vitamin D3 which promotes calcium and phosphorus absorption from the intestine and accelerates bone formation.

Part – II.

11th Bio Zoology Guide Chemical Coordination and Integration Additional Important Questions and Answers

I. Choose The Correct Answer

Question 1.
Which of the following is not related to hormones?
(a) They are secreted by ductless glands
(b) They act on the target
(c) They act as chemical messengers
(d) They play an important role in indigestion
Answer:
(d) They play an important role indigestion

Question 2.
Find out the endocrine glands from the following.
a) Sebaceous gland
b) Sweat glands
c) Salivary glands
d) Thyroid gland
Answer:
d) Thyroid gland

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 3.
Which of the following is the function of Growth Hormone?
(a) It increases blood pressure
(b) It influences the metabolism of carbohydrates, proteins, and lipids
(c) It stimulates melanin synthesis in melanocytes
(d) It promotes reabsorption of water by nephrons
Answer:
(b) It influences the metabolism of carbohydrates, proteins, and lipids

Question 4.
Where is the pituitary situated?
a) On the ethmoid bone
b) On sella turcica
c) On the foramen of Monro
d) On the Rathke’s packet
Answer:
b) On sella turcica

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 5.
The retention of nitrogen is due to this hormone.
a) TSH
b) GH
c) FSH
d) ACTH
Answer:
b) GH

Question 6.
A person is unable to sleep normally. He may not get proper secretion of?
(a) Thyroxine
(b) Vasopressin
(c) Melatonin
(d) Oxytocin
Answer:
(c) Melatonin

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 7.
A male child is born to a parent as he grew if FSH and LH are not properly secreted what happens to the male child.
a) He grows like a normal male child
b) He grows and he shows stunted growth
c) Secondary sexual characters are not developed properly
d) He grows as a mentally depressed male
Answer:
c) Secondary sexual characters are not developed properly

Question 8.
These hormones are collectively known as Gonadotropins?
a) Oxytocin and ADH
b) Oestrogen and Progestron
c) Testosterone and androgens
d) FSH and LH
Answer:
d) FSH and LH

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 9.
Which adrenal hormone is concerned with maintaining electrolytes, osmotic pressure and blood pressure?
(a) Cortisol
(b) Glucocorticoids
(c) Aldosterone
(d) Adrenalin
Answer:
(c) Aldosterone

Question 10.
Prabhu is working in a MNC Company. He has to do night shift once in every fifteen days.
Aftern a few years he is suffering from sleeplessness (in somnia) What may be the cause of his problem.
a) It may be becauses of his nature of work
b) More work pressure
c) The sleepwake cycle is disturbed due to the irregular synthesis of melotonin hormone
d) Due to the metabolic disturbances
Answer:
c) The sleepwake cycle is disturbed due to the irregular synthesis of melotonin hormone

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 11.
Name the structure that connects the lobes of thyroid gland?
a) Acinus
b) Ischium
c) Isthmus
d) bridge tissue
Answer:
c) Isthmus

Question 12.
Which of the following is the function of Glucogon?
(a) It increases the cellular utilization of glycogen into glucose
(b) It promotes the breakdown of glycogen into glucose
(c) It inhibits the breakdown of glycogen into glucose
(d) It inhibits the production of glucose from non-carbohydrate sources
Answer:
(b) It promotes the breakdown of glycogen into glucose

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 13.
Assertion: The Oxyphil cells of parathyroid secrete parathormone
Reason: The chief cells of parathyroid regulates the synthesis of parathormone
a) Assertion and Reason are correct
b) Assertion incorrect and the reason is wrong
c) The assertion is true. The reason is false
d) Both the assertion and reason are false.
Answer:
d) Both the assertion and reason are false.

Question 14.
Which of the following is not the function of progesterone?
(a) Implantation of the zygote in the uterus
(b) Decreasing the contraction of the uterus
(c) Formation of placenta
(d) Maturation of reproductive organs
Answer:
(d) Maturation of reproductive organs

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 15.
Which of the following option shows the with its action matched hormones
(given in column I) (given in column II)

Column I Column II
A Pituitary i) Partial endocrine gland
B Thyroid ii) Secretes steroid hormone oestrogen
C Ovary iii) Thyroxine regulates basal metabolic rate
D Thymus iv) Anterior lobe of pituitary originate from Rathke’s pouch

a) A – ii; B – iv; C – i; D – iii
b) A – iv ; B – iii; C – ii; D – i
c) A – iii; B – ii; C – iv; D – i
d) A – iv; B – i; C – iii; D – ii
Answer:
b) A – iv ; B – iii; C – ii; D – i

Question 16.
These are known as suprarenal glands.
a) Thymus gland
b) Pancreas
c) Adrenal gland
d) Ovary
Answer:
c) Adrenal gland

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 17.
Find out the hormone which are catecholamines.
a) Thyroxine
b) Insulin
c) Adrenalin
d) Glucagon
Answer:
c) Adrenalin

Question 18.
Why does cretenism occur?
(a) Hypothyroidism in adults
(b) Hypothyroidism in infants
(c) Hyperthroidism in adults
(d) lower level of iodine in the blood
Answer:
(b) Hypothyroidism in infants

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 19.
This hormone promotes the activation of Vitamin D thus by absorbing calcium?
a) Calcitonin
b) Thymosin
c) Parathormone
d) Thyroxine
Answer:
c) Parathormone

Question 20.
Does hypocalcemia occur due to?
(a) Hypersecretion of parathyroid hormone
(b) Hyposecretion of parathyroid hormone
(c) Hypersecretion of cortisol
(d) Hyposecretion of cortisol
Answer:
(b) Hyposecretion of parathyroid hormone

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 21.
Name the cells that secrete somatostatin
a) a cells
b) b cells
c) Lampda cells
d) delta cells
Answer:
d) delta cells

Question 22.
Why is insulin tablet not advisable for chronic diabetic Mellitus patients?
a) It takes more time to act
b) The insulin find it difficult to reach the substrate
c) Insulin is easily digested by the digestive enzymes
d) The insulin is not an effective one.
Answer:
c) Insulin is easily digested by the digestive enzymes

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 23.
Excess secretion of cortisol leads to
(a) Addison’s disease
(b) Grave’s disease
(c) Cushing’s syndrome
(d) Gull’s disease
Answer:
(c) Cushing’s syndrome

Question 24.
Contraction of the uterus leads to miscarriages in pregnant women.
What would be administered to evacuate the embryo?
a) ADH
b) Vasopressin
c) Androgen
d) Oxytocin
Answer:
d) Oxytocin

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 25.
In the case of thyrotecdomic patients, what is advisable to give along with the thyroxine?
a) Insulin
b) Thyroglobulin
c) Parathormone
d) Adrenalin
Answer:
c) Parathormone

Question 26.
The hyposecretion of vasopressin results in ……………..?
(a) Diabetes mellitus
(b) Diabetes insipidus
(c) Ketosis
(d) Hyperglycemia
Answer:
(b) Diabetes insipidus

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 27.
Name the hormone that stimulates the synthesis of HCl.
a) Enterokinase
b) Pepsinogen
c) Gastrin
d) Secretin
Answer:
c) Gastrin

Question 28.
What is the other name for type I diabetes?
a) Insulin-dependent diabetes
b) Non-insulin-dependent diabetes
c) Sensitive diabetes
d) Dependent types
Answer:
a) Insulin-dependent diabetes

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 29.
Which is called the second messenger.
a) Receptor cells
b) CAMP
c) Adenylate
d) Substrate
Answer:
b) CAMP

Question 30.
In the following diagram what are the parts A, B, C, and D represent?
Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration 2
I) A) Pineal body B) Anterior tube C) Capillary bed D) Infundibulum
II) A) Hypophyseal vein B) Optic chiasma C) Endocrine cells D) Artery
III) A) Infundibuim B) Posterior C) Hypophyseal vein D) Endocrine cells
IV) A) Endocrine cells B) Infundibulum C) Paradisaical D) Pineal body
Answer:
III) A) Infundibuim B) Posterior C) Hypophyseal vein D) Endocrine cells

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 31.
Find out the true and false statements from the following and on that basis find the correct answer.
i) ADH causes blood vessels to dialate
ii) The ‘c’ cells of the thyroid gland secretes calcitonin
iii) Zona fasciculate secretes cortisol
iv) Minerals corticoids regulate water balance
i) a) True b) False c) True
ii) a) False b) True c) False
iii) a) False b) True c) False
iv) a) False b) False c) True
Answer:
iv) a) False b) False c) True

Question 32.
Which part interlinks both the nervous system and endocrine system?
a) Receptor molecules
b) Target tissue
c) Hypothalamus
d) Infundibulum
Answer:
c) Hypothalamus

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 33.
Which of the following disease is not caused by iodine or thyroxine deficiency?
a) Sporodic goitre
b) Exophthalmic goitre
c) Simple goitre
d) Myxodema
Answer:
a) Sporodic goitre

Question 34.
Which is the correct location of the receptors of the hormones?
a) Extracellular matrix
b) Blood
c) Plasma membrane
d) Nucleus
Answer:
c) Plasma membrane

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 35.
The primary target of the hormones of the hypothalamus is
a) pineal gland
b) thymus
c) testis
d) pituitary
Answer:
d) pituitary

Question 36.
Functionally the adenohypophysis of the pituitary gland includes
a) anterior lobe
b) Posterior lobe
c) intermediate lobe
d) both (a) and (c)
Answer:
d) both (a) and (c)

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 37.
An outgrowth of the hypothalamus from the base of the brain develops into
a) pars nervosa
b) pars intermedia
c) pars distalis
d) pars intermedia
Answer:
a) pars nervosa

Question 38.
The hormone secreted by neurohypophysis is
a) ACTH
b) ADH
c) GH
d) TSH
Answer:
b) ADH

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 39.
Among the following hormones is the peptide hormone.
a) GH
b) TSH
c) FSH
d) LH
Answer:
a) GH

Question 40.
Among the following is not a glycoprotein hormone.
a) TSH
b) LTH
c) LH
d) FSH
Answer:
b) LTH

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 41.
Find out the protein hormone from the following.
a) LTH
b) FSH
c) TSH
d) ACTH
Answer:
a) LTH

Question 42.
Which is the pituitary hormone that is present in other vertebrates?
a) MSH
b) ACTH
c) TSH
d) GH
Answer:
a) MSH

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 43.
Find out the wrong statement about vasopressin or ADH
a) It promotes reabsorption of water and electrolytes by distal tubules of the nephron.
b) Causes constriction of blood vessels
c) It stimulates vigorous contraction of smooth muscles of the uterus during childbirth
d) It is a peptide hormone
Answer:
c) It stimulates vigorous contraction of smooth muscles of the uterus during childbirth

Question 44.
The growth hormone releasing hormone stimulates the
a) Thymus to release the hormone
b) Pituitary for synthesis and release of growth hormone
c) Testis to release gonadotropin
d) Adrenal to release growth hormone
Answer:
b) Pituitary for synthesis and release of growth hormone

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 45.
Posterior pituitary secretion is controlled by
a) hypothalamic hypophyseal portal blood vessel
b) neuroendocrine gland
c) hypophysis
d) hypothalamic hypophyseal axis
Answer:
d) hypothalamic hypophyseal axis

Assertion and Reason:- Directions: In the following questions a statement of Assertion is followed by a statement of reason. Mark the correct choice as;
a) If both Assertion and reason are true and reason is the correct explanation of assertion
b) If both Assertion and reason and true but reason is not the correct explanation of Assertion.
c) If assertion is true but reason is false
d) If both Assertion and reason are false

Question 46.
Assertion: Adrenalin nor-adrenalin, melatonin, and thyroid hormones are proteins
Reason: Derived from cholesterol mostly water-soluble
Answer:
d) If both Assertion and reason are false

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 47.
Assertion: Growth hormone stimulates chondrogenesis and osteogenesis
Reason: Growth hormones promote growth of all tissues and metabolic process of the body.
Answer:
a) If both Assertion and reason are true and reason is the correct explanation of assertion

Question 48.
Assertion: Adrenal medulla hormones are referred to as 3F hormones fight, flight, and hormones.
Reason: During emergency it increases heartbeat rate and blood pressure
Answer:
a) If both Assertion and reason are true and reason is the correct explanation of assertion

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 49.
Assertion: The effects of aldosterone, oestrogen FSH are long-lived as they alter the amount of m- RNA and protein in a cell
Reason: The action of cAMP are terminated by phosphodiesterases
Answer:
b) If both Assertion and reason and true but the reason is not the correct explanation of Assertion.

Question 50.
Assertion: The immunity of old age people, becomes week and causes sickness.
Reason: Due to degeneration of pineal gland thymosin level decreases
Answer:
c) If assertion is true but reason is false

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 51.
Assertion: JGA cells of the kidney stimulates erythropoiesis or formation of RBC
Reason: JGA cells also secrete Erythropoietin
Answer:
a) If both Assertion and reason are true and reason is the correct explanation of assertion

Question 52.
Assertion: Diabetes inspidus is marked by production of large amount of urine.
Reason: Hypo secretion of ADH leads to a condition of reduced water absorption. Thus the urine becomes diluted without sugar or glucose
Answer:
a) If both Assertion and reason are true and reason is the correct explanation of assertion

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 53.
The Luteinizing hormone in males is
a) Testosterone
b) ICSH
c) FSH
d) LTH
Answer:
b) ICSH

Question 54.
The cells that secrete parathyroid hormone is known as
a) chief cells
b) oxyphil cells
c) goblet
d) both b and c cells
Answer:
a) chief cells

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 55.
Find out the correct statement about pineal gland.
a) Stimulates the production and release of sperms.
b) Increases blood pressure.
c) It plays a central role and the regulation of circadian rhythm of our body and maintains the normal sleep wake cycle.
d) It is about 1cm in diameter and 0.5gm.
Answer:
c) It plays a central role and the regulation of circadian rhythm of our body and maintains the normal sleep wake cycle.

Question 56.
The BMR is regulated by
a) Parathormone
b) Thyrocalcitonin
c) Adrenalin
d) Thyroxine
Answer:
d) Thyroxine

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 57.
The primary function of the thymus gland is
a) regulation of body temperature
b) regulation of body growth
c) immunological functions
d) Secretion of thyrotropin
Answer:
c) immunological functions

Question 58.
A hormone secreted by adrenal gland and called life-saving hormone is
a) adrenaline
b) cortisone
c) aldosterone
d) Cortisol
Answer:
d) Cortisol

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 59.
Which of the following condition is not linked to a deficiency of thyroid hormone?
a) cretinism
b) goitre
c) Myxoedema
d) Exophthalmia
Answer:
d) Exophthalmia

Question 60.
Androgens are sex corticoids secreted from
a) Zona reticulate
b) Adrenal medulla
c) Zona glomerulosa
d) Acini
Answer:
a) Zona reticulate

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 61.
A gland which is well developed in newborn child and produce lymphocytes
a) Thyroid gland
b) Thymus
c) Parathyroid gland
d) Pineal gland
Answer:
b) Thymus

Question 62.
Which one reduces the blood calcium level and shows an opposite effect to parathormone?
a) ADH
b) Insulin
c) Thyrocalcitonin
d) Thyroxine
Answer:
c) Thyrocalcitonin

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 63.
Secretion of HCl and pepsinogen is controlled by
a) Cholecystokinin
b) Gastrin
c) Calcitriol
d) Renin
Answer:
b) Gastrin

Question 64.
A man has an IQ equivalent to that of a boy 5 years old this is due to the deficiency of which hormone?
a) Thyroxine
b) Adrenaline
c) Aldosterone
d) Somatotropin
Answer:
a) Thyroxine

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 65.
Which of the following option shows the correct matching of disorders and causes.
A) Addison’s disease -(i) Hypo secretion of thyroid
B) Cushing’s syndrome – (ii) Hypersecretion of parathyroid hormone
C) Softening of bone – (iii) Hypo secretion of glucocorticoids
D) Gull’s disease (in adults) – (iv) Excess secretion of cortisol
Codes:
a) A – (ii); B – (i); C – (iii); D – (iv)
b) A – (iii); B – (iv); C – (ii); D – (i)
c) A – (iii); B – (ii); C – (i); D – (iv)
d) A – (iv); B – (iii); C – (iv); D – (ii)
Answer:
b) A – (iii); B – (iv); C – (ii); D – (i)

Question 66.
A person is having problems with calcium and phosphorous metabolism in his body.
Which one of the following glands may not be functioning.
a) Parathyroid
c) Pancreas
b) Parotid
d) Thyroid
Answer:
a) Parathyroid

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 67.
The presence of fat and acid in the diet induces the secretion of
a) Gastrin
b) Secretion
c) Cholecystokinin
d) Calcitriol
Answer:
c) Cholecystokinin

Question 68.
Which is an amino acid derivative hormone?
a) Epinephrine
c) Progesterone
b) Oestrogen
d) Relaxin
Answer:
a) Epinephrine

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 69.
Which of the following is a mineralocorticoid?
a) Testosterone
b) Cortisol
c) Adrenalin
d) Aldosterone
Answer:
d) Aldosterone

Question 70.
Which hormone increases the rate of protein biosynthesis chondrogenesis and osteogenesis and helps in the retention of minerals?
a) Prolactin
b) Somatotrophic hormone
c) Thyrotropin
d) Glucagon
Answer:
b) Somatotrophic hormone

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 71.
The male sex hormones are secreted by
a) Zona glomerulosa
b) Fat cells
c) Lay-dig cells
d) Acini
Answer:
c) Lay-dig cells

Question 72.
Which of the following pituitary hormone is secreted without the involvement of a releasing hormone?
a) Thyrotropin
b) Follicle-stimulating hormone
c) Oxytocin
d) Prolactin
Answer:
c) Oxytocin

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 73.
Match the following columns.

Column I Column II
A Melatonin 1. T-lymphocyte formation
B Thymus 2. Formation of RBC
C Insulin 3. Sleep-wake cycle
D Erythropoietin 4. Hypoglycemic hormone

Code:
Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration 3
Answer:
b) A -3,B-1,C-4,D-2

Question 74.
Which hormones can easily pass through the cell membrane and bind to their receptors and alter gene function?
a) Peptide hormones
b) Amino acid-derived hormones
c) Neurohormones
d) Steroid hormones
Answer:
d) Steroid hormones

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 75.
The hormone which helps to find out conception is
a) FSH
b) Oestrogen
c) HCG
d) LH
Answer:
c) HCG

Question 76.
Gigantism and Acromegaly are due to
a) Hypothyroidism
b) Hyperthyroidism
c) Hypopituitarism
d) Hyper pitituitarism
Answer:
d) Hyper pitituitarism

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 77.
After performing the functions in the target organs how hormones are inactivated and excreted?
a) By intestine
b) By lungs and skin
c) By liver and Kidney
d) Both a and b
Answer:
c) By liver and Kidney

Question 78.
The half-life period of insulin is
a) 6 minutes
b) 8 minutes
c) 15 minutes
d) 7 minutes
Answer:
a) 6 minutes

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 79.
The time taken by insulin to be cleared from circulation is
a) 10-20 minutes
b) 10-15 minutes
c) 5-10 minutes
d) 2-10 minutes
Answer:
b) 10-15 minutes

(2 Marks)

II. Very Short Answer.

Question 1.
What are the causes of bone cyst formation?
Answer:
Hyper para thyrodism causes demineralization of bone causes bone cyst makes the bone fragile and soft.

Question 2.
Why is the hypothalamus considered a neuroendocrine gland?
Answer:
The hypothalamus alone with its neural function produces hormones. Hence it is considered a neuro-endocrine gland.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 3.
What is the meaning of the word hormone?
Answer:
Hormone means to excite.

Question 4.
Write on the origin of the pituitary gland?
Answer:
The anterior lobe of the pituitary gland originates from the embryonic invagination of pharyngeal epithelium called Rathke’s pouch. The posterior lobe originates from the base of the brain as an outgrowth of the hypothalamus.

Question 5.
What is meant by Homeostasis?
Answer:
Maintenance of the constant internal environment of the body by the different coordinating system is homeostasis.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 6.
What is Pars nervosa?
Answer:
The neurohypophysis of the pituitary gland is known as pars nervosa.

Question 7.
Give example for partial endocrine glands.
Answer:
Pancreas, gastrointestinal tract epithelium kidney, heart gonads, and placenta.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 8.
Write a paragraph on the Growth Hormone?
Answer:
Growth hormone (GH):
It is also known as somatotropic hormone (STH) or Somatotropin. It is a peptide hormone Growth hormone promotes the growth of all the tissues and metabolic processes of the body. It influences the metabolism of carbohydrates, proteins, and lipids and increases the rate of protein biosynthesis in the cells.

It stimulates chondrogenesis (cartilage formation), osteogenesis (bone formation) and helps in the retention of minerals like nitrogen, potassium, phosphorus, sodium, etc., in the body. GH increases the release of fatty acid from adipose tissue and decreases the rate of glucose utilization for energy by the cells. Thus it conserves glucose for glucose-dependent tissues, such as the brain.

Question 9.
Name the hormone of peptide nature?
Answer:
Insulin, glucagon, and pituitary hormone are water-soluble.

Question 10.
What are steroid hormones?
Answer:
They are derived from cholesterol and are lipid-soluble.
Ex. Cortisol aldosterone testosterone oestrogen progesterone.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 11.
What is the role of the Follicle-stimulating hormone in a man?
Answer:
Follicle-stimulating hormone (FSH):
FSH is a glycoprotein hormone that regulates the functions of the gonads (ovary and testis). In males, FSH along with androgens acts on the germinal epithelium of seminiferous tubules and stimulates the production and release of sperms (spermatogenesis). In females, FSH acts on the ovaries and brings about the development and maturation of gratfran follicles.

Question 12.
What is the function of LH in females?
Answer:
LH induces ovulation maintains the corpus luteum and promotes the synthesis and release of ovarian hormones.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 13.
Why there is a short life span for hormone-like insulin?
Answer:
Insulin hormone is usually short-lived as it has to work through a second messenger (cAMP) system.

Question 14.
Why the hormones steroid may be long-lived?
Answer:
The effect of steroid hormones is long-lived as they alter the amount of mRNA and protein in a cell.
Ex. Aldosterone oestrogen FSH.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 15.
How do the hormones reach and act on the specific target organs?
Answer:

  • The hormones are released into the blood and circulated as chemical signals
  • The target organs contain receptor molecules either on the surface or within the cell.
  • The cells that contain the receptor molecules specific to the hormone are physiologically activated.
  • Whereas other hormones that come in contact can not be activated.

Question 16.
Name the three zones which are present in the Adrenal gland.
Answer:

  1. Zona glomerulosa
  2. Zona fasciculata
  3. Zona reticularis

Question 17.
Differentiate amines and steroid hormones
Answer:

Amines Steroids
A. Small water-soluble 1. Mostly lipid-soluble
B. Derived from tyrosine or tryptophan 2. Derived from Cholesterol
C. Examples are Adrenalin Noradrenalin, Melatonin, and thyroid hormone 3. Examples are cortisol, aldosterone, testosterone, oestrogen, and progesterone

Question 18.
Differentiate exocrine glands from endocrine glands.
Answer:

Exocrine glands Endocrine glands
1. They have ducts to carry their substances to the membrane surfaces 1. These lack ducts and so release their hormone to the surrounding tissue fluid
2. They secrete enzymes, saliva, and sweat 2. Their secretions are collectively termed hormones.
3. Eg. Salivary gland, Sweat gland, and Gastric glands 3. Eg. Pituitary, Thyroid Pineal, Adrenal Parathyroid

Question 19.
How endocrine glands be classified based on their secretary function?
Answer:

  • Exclusive endocrine glands, e.g. Pituitary thyroid, Parathyroid, Pineal, Adrenal
  • Neuroendocrine gland – Hypothalamus
  • Partial endocrine glands, e.g. Pancreas, gastrointestinal tract epithelium, kidney, heart gonads, and placenta – have endocrine tissues.

Question 20.
The pituitary gland is known as the master endocrine glands. Justify the statement.
Answer:

  • The pituitary gland is known as the master endocrine gland, but it is in turn controlled by the hypothalamus and so the statement may not be totally applicable.
  • The hypothalamus with its neurosecretory cells produces neurotransmitters which regulate the secretions of the pituitary.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 21.
Write about the location and dimension of the pituitary gland.
Answer:

  • The pituitary gland is located in the bony cavity of the sphenoid bone the sella tunica at the base of the brain so is also called the hypothalamus cerebri.
  • it is about one centimeter in diameter and 0.5gm in weight.

Question 22.
What is an infundibulum?
Answer:
The pituitary gland is connected to the hypothalamic region of the brain by a stalk called the infundibulum.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 23.
What is Rathke’s pouch?
Answer:
The anterior lobe of the pituitary originates the embryonic invagination of the pharyngeal epithelium called Rathke’s pouch.

Question 24.
Comment on MSH or Melanocyte stimulating hormone.
Answer:

  • In mammal’s role of Pass, intermedia is insignificant.
  • In other vertebrates pass intermedia secretes melanocyte-stimulating hormone or MSH.
  • It induces pigmentation in the skin.

Question 25.
What are the functions of the pineal gland?
Answer:
In humans, the pineal gland or epiphysis cerebri or conarium is located behind the third ventricle of the brain and is formed of parenchymal cells and interstitial cells.

It secretes the hormone, melatonin, which plays a central role in the regulation of the circadian rhythm of our body and maintains the normal sleep-wake cycle. It also regulates the timing of sexual maturation of gonads. In addition, melatonin also influences metabolism, pigmentation, menstrual cycle and defence mechanism of our body.

Question 26.
What are the other names of Luteotropic hormones?
Answer:

  1. Luteotropin
  2. Lactogenic hormone
  3. Protein
  4. Mammotropin

Question 27.
Name the hormones that their secretions are regulated by negative feedback mechanisms?
Answer:

  • Thyroid-stimulating hormone TSH or Thyrotropin
  • Adreno corticotropic hormone or ACTH

Question 28.
Give the meanings of the word pituitary oxytocin and Hormone?
Answer:

  1. Pituitary means “to grow under”.
  2. Oxytocin means “quick birth”.
  3. Hormone means “to excite”.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 29.
Mention the importance of Luteotropic hormone in females?
Answer:
It stimulates milk secretion after the childbirth.

Question 30.
Why prolactin is called luteotropic hormone?
Answer:

  • High prolactin secretion during lactation
  • Since it induces the corpus luteum hence named as luteotropic hormone.

Question 31.
Point out the role of oxytocin in females?
Answer:

  • It stimulates vigorous contraction of the smooth muscles of uterus during child birth.
  • Ejection of milk from the mammary glands after child birth.

Question 32.
Name the hormones that play a key role in milk secretion?
Answer:

  • Prolactin or lactogenic hormone or mammotropin or luteotropic hormone.
  • Oxytocin.

Question 33.
Name the hormone of pituitary that act on bloodvessels?
Answer:
The vasopressin causes constriction of blood vessels when released in large amount and in-creases blood pressure.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 34.
Which gland is located behind the third ventricle of brain?
Answer:
The pineal gland or epiphysis cerebri or conarium.

Question 35.
Which is the largest endocrine in the body and where it is located?
Answer:

  • The thyroid gland is the largest gland.
  • It is a bibbed gland located below the larynx on each side of upper trachea.

Question 36.
Name the hormones secreted by thyroid gland.
Answer:

  • Tri-iodo thyronine or T3
  • Tetra-iodo thyromne or T4 or Thyroxine
  • Thyrocalcitonin

Question 37.
What are parafollicular cells or ‘C’ cells?
Answer:

  • These are the cells in the thyroid gland.
  • These cells secrete a hormone called thyrocalcitonin.

Question 38.
What element is important for synthesis of thyroid hormones? In what quantity it is essential?
Answer:

  • Iodine is essential for the normal synthesis of thyroid hormones.
  • About 1m. a week of Iodine is required.

Question 39.
Mention the normal glucose level in prepandial and postpandial test for glucose?
Answer:

  1. Prepandial- 70-100 mg/dl (Fasting)
  2. Post pandial (About 2 hours after food) – 110 – 140mg/ dl.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 40.
Is it advisable to take alcohol frequently? What ill effects does it cause over the body?
Answer:

  • Alcohol consumption has widespread effect on endocrine system.
  • It impairs the regulation of blood glucose level.
  • More over it reduces the testosterone level
  • Increases the risk of osteoporosis.

Question 41.
What is the injection administered to diabetic patients? Why is it given as injection and not as oral pills?
Answer:

  • Humiline-N is administered to diabetic patients.
  • Human insulin is administered as injection and not by oral consumption.
  • The reason is if it is administered by oral consumption it may be digested by digestive enzymes.

Question 42.
What is sporadic goiter?
Answer:

  • It is a genetic disease
  • It is not caused by iodine or thyroxine deficiency.

Question 43.
Why laughing is good for health?
Answer:
It reduces the secretion of stress hormone, adrenalin and makes us to relax.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 44.
Define circadian rhythm.
Answer:
It is the 24-hour cycle of biological activities associated with natural periods of light and darkness.
Eg. Sleep wake cycle, body temperature, appetite etc.

(3 Marks)

III. Short Answer

Question 1.
What is simple goiter? What are its symptoms?
Answer:

  • Simple goitre is otherwise known as endemic goitre.
  • It is due to the hypo secretion of thyroxine.
  • The symptoms are Enlargement of thyroid gland, Fall in serum thyroxine level, Increased TSH secretion.

Question 2.
What is tetany?
Answer:

  • The hyposecretion of parathyroid hormones leads to a decrease in calcium level and increase in phosphate level, it causes.
  • convulsion in muscle, locking of jaws, increased heart beat rate increased body temperature muscular spasm lead to tetany.

Question 3.
What is cushing’s syndrome? What are its symptoms?
Answer:
The excess secretion of cortisol causes cushing’s syndrome. The symptoms are obesity of the face and trunk.

  1. Redness of face hand and feet.
  2. Thick skin.
  3. Excessive hair growth
  4. Loss of mineral from bone
  5. Systolic hypertension

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 4.
What is the cause of dwarfism?
Answer:
It is due to the hypo-secretion of growth hormone in children in which skeletal growth and sexual maturity is arrested. They attain a maximum height of 4 feet only.

Question 5.
What is Gigantism?
Answer:

  • Due to the hyper-secretion of growth hormone in children there is a over growth of skeletal
  • structure may occur up to 8 feet height. The visceral growth is not appropriate with that of limbs.

Question 6.
You are walking on the road, suddenly a man with a knife in his hand comes in front of you. What would be your reaction?
Answer:
I will get bimple goose due to the Surge of vasodielation on the arector pili muscle and though, i am very much frightened, i will fight with that man. i will get that energy by the action of the hormone adrenalin.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 7.
Why oxytocin is considered as quick or rapid birth?
Answer:
Oxytocin stimulates the contraction of the smooth muscles of uterus during child birth which helps in the expulsion of foetus, hence it is called as quick birth.

Question 8.
Why thymus is considered as a lymphoid organ?
Answer:
Thy lymphocytes that comes to thymus is educated to become immuno competent T lymphocytes and provides cell mediated immunity. Hence thymus is a lymphoid organ.

Question 9.
Why is gluco corticoids considered in the life saving activity?
Answer:
During the period of emergency the gluco corticoids stimulate the synthesis of glucose from lipid and protein by lipolysis and proteolysis and releases energy to meet that emergency situation.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 10.
Why cortisol works as a stress combat hormone?
Answer:

  • Cortisone involved in maintaining cardio vascular and kidney functions. It produces anti inflammatory reactions and suppresses the immune response, it stimulates the RBC production.
  • Hence it is known as stress combat hormone.

Question 11.
How do the hormones act in the target tissue?
Answer:

  • The hormones are released into the blood and circulated as chemical signals and act on specific target organs.
  • Hormones may speed up or slow down or alter the activity of the target organs.
  • The hormones secreted do not remain permanently in the blood.
  • They are converted by the liver into inactive compound and excreted by kidneys.

Question 12.
What is a limbic system?
Answer:

  • It is a collection of special structures located in the middle of the brain.
  • It is also known as paleo mammalian brain.
  • It controls emotions, behavior, motivation of long term memory and olfaction.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 13.
What are exocrine glands? Give examples
Answer:

  • The exocrine glands have ducts to carry their secretion to the membrane surfaces.
  • They secrete enzymes, saliva arid sweat.
  • Examples are salivary gland, gastric gland.

Question 14.
Write down the functions of hypothalamus.
Answer:

  1. Hypothalamic hormones control anterior pituitary secretion through hypothalamic hypophyseal portal blood vessel.
  2. The nerve signal produced by the hypothalamic hypophyseal axis control the posterior pituitary secretion.
  3. Hypothalamus maintains homeostasis.
  4. Blood pressure
  5. Body temperature.
  6. Cardio and fluid electrolyte balance of the
  7. As the part of limbic system it influences various emotional responses.

Question 15.
Draw the diagram of the hypothalamus and pituitary gland and label the following parts.
Answer:
A. Anterior lobe
B. Posterior lobe
C. Hypothalamus
D. Interior Hypophyseal artery
E. Endocrine cells
F. Hypophyseal vein
Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration 4

Question 16.
Draw the diagram of thyroid gland and label the following parts
Answer:
A Thyroid cartilage
B. Thyroid gland
C. Trachea
D.Isthumus
Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration 5

Question 17.
Draw the diagram of thyroid gland and label the following parts
A. Capsule
B. Cortex
C. Medulla
D. Blood Vessels
Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration 6

Question 18.
Explain the role of leuteinizing hormone (LH) in male and females.
Answer:

  • It is a glycoprotein hormone
  • It is also known as Interstitial cell stimulating hormone (ICSH) in males.
  • The ICSH hormones acts on the interstitial cells of testis to produce the male sex hormone testosterone.
  • In females along with FSH matures the ovarian follicles.
  • LH independently induces ovulation, maintains the corpus luteum and promotes synthesis and release of ovarian.
  • FSH and LH secretion starts only during pre pubertal period.
  • FSH and LH are collectively referred as gonadotropins.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 19.
Compare the structural difference of vasopressin and oxytocin. Vasopressin Oxytocin
Answer:

Exocrine glands Endocrine glands
1. Composed of a amino acids 1. Composed of a amino acids
2. Amino acid sequence is cysteine – tyrosine – Phenyl alanine – glutamine arspargine – cysteine – proline – argirune – glycine. 2. Amino acid sequence is – cysteine – tyrosine –
Isoleucine – Glutamine – aspargine – cysteine –
proline – leucine – glycine.

Question 20.
How does the posterior lobe of the pituitary help in osmoregulation?
Answer:

  • ADH is a peptide hormone
  • It promotes absorption of water and electrolytes by distal tubules of nephron and there by reduces loss of water through urine.
  • Hence it is called as anti diuretic hormone.
  • ADH deficiency causes Diabetes insipidus which induces the production of large amount of urine.
  • This is how it helps in osmoregulation.
  • ADH when released in large amount causes constriction of blood vessels and increases blood pressure.

Question 21.
Explain the role of melatonin in our body.
Answer:

  • It is secreted by pineal gland.
  • It plays a central role in the regulation of circadium rhythm of our body
  • Maintains the normal sleep wake cycle.
  • It also regulates the timing of sexual maturation of gonads.
  • In addition it also influences metabolism, pigmentation, menstrual cycle and defence mechanism of our body.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 22.
List out the role of thyroxine or tetra iodo thyronine (T4) in our body.
Answer:

  • It regulates the Basal Metabolic Rate (BMR) and body heat production.
  • It stimulates protein synthesis and promotes growth
  • It is essential for the development of skeletal and nervous system.
  • It plays an important role in maintaining blood pressure
  • It reduces serum cholesterol levels.
  • Optimum levels of thyroxine in the blood are necessary for gonadial functions.

Question 23.
Which hormone is called hypercalcemic hormone? Explain its role.
Answer:

  • The parathyroid hormone (PTH) is the hypercalcemic hormone.
  • It is a peptide hormone.
  • It involves in controlling the calcium and phosphate homeostasis.
  • The secretes or PTH is controlled by calcium level in the blood.
  • It increases the blood calcium level by stimulating osteoclasts to dissolve the bone matrix.
  • As a result calcium and phosphate are released into the blood.
  • PTH enhances the re-absorption of calcium and exertion of phosphates by the renal tubules.
  • It promotes activation of vitamin D to increase calcium absorption by intestinal mucosal cells.

Question 24.
Explain the role of heart as a partial endocrine gland.
Answer:
1. In the heart, cardiocytes on the atrial walls secretes an important peptide hormone called Atrial Natriuretic Factor (ANF)
2. When blood pressure is increased ANF is secreted and causes dilation of the blood vessels to reduce the blood pressure.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 25.
Is it good to take synthetic soft drinks? Why?
Answer:

  • It is not good to take synthetic soft drinks.
  • The branded soft drinks damage our endocrine system.
  • While consuming soft drinks the sugar level increases in blood. Which leads to elevated insulin secretion
    to reduce the blood glucose level.
  • The elevated insulin level diminishes immunity.
  • It causes obesity, cardio-vascular disorders etc.

Question 26.
The doctors avoid prescribing steroid tablets most often. Why?
Answer:
The abuse of steroids can cause serious health problems such as.

  • HighB.P.
  • Heart diseases.
  • Liver damage
  • Cancer
  • Stroke
  • Blood clotsa

Side effects such as

  1. Nausea
  2. V omiting
  3. Ligament and tendon injuries
  4. Head ache
  5. JointPain
  6. Muscle cramps
  7. Diarrhoea
  8. Sleep problem

Question 27.
if para-thyroid gland shows hyper-secretion. What will be the symptoms of this disorder?
Answer:

  • The excess secretion of parathyroid gland is known as hyperparathyroidism
  • Symptoms are Demineralisation of bone.
  • Cyst formation
  • Softening of bone
  • Loss of muscletone
  • General weakness
  • Renal disorders.

Question 28.
Differentiate Glycogenolysis from gluconeogenesis.
Answer:

  • Glycogenolysis is breakdown of glycogen to glucose
  • This process is carried out in the liver by the Glucagon hormone.
  • Glucagon thus releases glucose from the liver cells increasing Gluconeogenesis.
  • it is the synthesis of glucose from lactic acid and from non-carbohvdrate molecules is called Gluconeogenesis. this increases the blood glucose levels.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 29.
Mention the symptoms of diabetes mellitus.
Answer:

  • Poly urea – Excessive urination
  • Polyphagia – Excessive intake of food
  • Polydipsia – Excessive consumption of liquids due to thirst.
  • Ketosis – Breakdown of fat into glucose results in accumulation of ketone bodies.

Question 30.
Give a short account on hypothalamus.
Answer:

  • Hypothalamus is a small cone shaped structure that projects downward from the brain ending into the pituitary stalk.
  • It interlinks both the nervous system and endocrine system.
  • Pituitary gland is controlled by the hypothalamus.
  • It produces neuro transmitters which act either as a releasing hormone or as an inhibitory hormone.
  • Hypothalamus contains groups of neuro secretory cells which produces neuro transmitters which regulate the secretions of the pituitary gland.

Question 31.
Comment on pineal gland.
Answer:

  • It is located behind the third ventricle of brain.
  • In human it is called epiphysis cerebri conarium.
  • It is formed of parenchymal cells and interstitial cells.
  • It secretes the hormone melatonin.
  • It plays a central role in the regulation of circadian rhythm of our body and maintains the normal sleep wake cycle.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 32.
Write down the functions of thyrocalcitonin.
Answer:

  1. It is a polypeptide hormone.
  2. It regulates the blood calcium and phosphate levels.
  3. It reduces the blood calcium level and oppose the effects of parathyroid hormone.

Question 33.
Give a brief account on parathyroid gland.
Answer:

  • In man, four tiny parathyroid glands are found in the posterior wall of the thyroid glands.
  • It composed of two types of cells. The chief cells and oxyphil cells.
  • The chief cells secrete parathyroid hormone.
  • The functions of oxyphil cells are not known.

Question 34.
Write short notes on thymus gland.
Answer:

  • Thymus gland is partially an endocrine and partially a lymphoid gland.
  • It is a bi-lobed structure located just above the heart and aorta behind the sternum.
  • It is covered by a fibrous capsule.
  • Anatomically it is divisible into an outer cortex and an inner medulla.
  • It secretes four hormones such as thymulin, thymosin, thymopoietin and thymic humoral factor (THF).
  • The primary function is the production of immuno competent T lymphocytes which provides cell mediated immunity.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration 7

Question 35.
Write about Acromegaly.
Answer:
Acromegaly is due to excessive secretion of growth hormone in adults.
Symptoms:-

  • Over growth of hand bones, feet bones, jaw bones
  • Malfunctioning of gonads
  • Enlargement of viscera, tongue, lungs, heart, liver, spleen and endocrine gland like thyroid adrenal.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 36.
What is hyperparathyroidism? Write down its symptoms.
Answer:
1. Hyperparathyroidism is caused due to excess parathyroid hormone in blood.
Symptoms:-

  • Demineralisation of bones
  • Cyst formation, softening of bone.
  • Loss of muscle tone
  • General weakness
  • Renal disorders.

Question 37.
Comment on Addison’s disease.
Answer:
Addison’s disease is caused due to hyposecretion of glucocorticoids and mineralocorticoids from the adrenal cortex.
Symptoms:-

  • Muscular weakness, Low BP
  • Loss of appetite, vomiting
  • Hyper pigmentation of the skin
  • Low metabolic rate, subnormal temperature.
  • Weight loss reduced blood volume.
  • Low aldosterone level increases urinary excretion of NaCl and water and decreases potassium excretion leading to dehydration.

Question 38.
Give reasons for Diabetes insipidus and point out its symptoms.
Answer:
Diabetes insipidus is caused due to hypo secretion of vasopressin.
Symptoms:-

  • Polyurea-frequent urination
  • Polydipsia – excessive consumption of liquids due to thirst.

Question 39.
Define BMR.
Answer:
The amount of energy needed to keep the body at rest.

Question 40.
Write down the general function of adrenalin hormone and its nature of secretion?
Answer:
Function:- The general function of nor adrenalin is to mobilize the brain and body for action. Nature of secretion: Its secretion is less during sleep, more during wakefulness and reaches much higher levels during stress situations. This response is known as ‘fight or flight’ response.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 41.
Old age people are sick often why?
Answer:
Due to degeneration of thymus gland, thymosin level decreases as a result the immunity of old age people becomes weak and causes sickness.

Question 42.
What is the role of pass intermedia in mammals and in other vertebrates?
Answer:

  • In mammals the role of pass intermedia is insignificant.
  • In other vertebrates it secretes melanocyte stimulating hormone (MSH)
  • It induces pigmentation in skin.

(5 Marks)

IV. Brief Answers

Question 1.
Describe the mechanism of peptide hormone action with a diagram.
Answer:
Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration 8

  • Peptide hormones cannot cross the phospholipid cell membrane and bind to the receptors on the exterior cell surface.
  • They are transported to the golgi which is the site of modification.
  • It acts as a first messenger in the cell.
  • Hormones generate a second messenger like cyclic AMP (cAMP) that regulates cellular metabolism. This cAMP is catalyzed by the adenylate cyclase ezyme.
  • The interaction between the hormone surface and the effect of cAMP within the cell is known as a signaling cascade. There may be amplication at each step.
  • One hormone molecule may bind to multiple receptor molecules before it is degraded.
  • Each receptor activates to form more cAMP and produces more signals.

Question 2.
Describe the mechanism of action of steroid hormone.
Answer:

  • Steroid hormones can easily cross the cell membrane and bind their receptors which may be intracellular or intercellular.
  • Then they pair up with another receptor and form a receptor-hormone complex. This can bind to DNA and alter its transcription.
  • As it changes the mRNA and protein the effect will be with stand for a long time. Eg. Estrogen

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration 9

Question 3.
What is typical about Addison’s disease.
Answer:

  • There is a hyper pigmentation of the skin. It is caused due to hypo secretion of glucocorticoids from the adrenal cortex.
  • Muscular weakness low BP, loss of appetite vomiting, low metabolic rate subnormal temperature reduced blood volume and weight are the other symptoms of Addison’s disease.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 4.
What is the cause of cretinism? What are the symptoms?
Answer:

  • Hypothyroidism is the cause of cretinism in infants. There is a retarded skeletal growth absence of sexual maturity, retarded mental ability, thick wrinkled skin protruded enlarged tongue bloated face thick and short limbs.
  • There is low BMR, slow pulse rate subnormal body temperature and elevated blood cholesterol levels.

Question 5.
What are the hormones responsible for maintaining blood glucose levels?
Answer:
Insulin and glucagon are the hormones secreted by Islets of Langerhans of the pancreas:-
Insulin:
Insulin is a peptide hormone and plays an important role in glucose homeostasis. Its main effect is to lower blood glucose levels by increasing the uptake of glucose into the body cells, especially muscle and fat cells. Insulin also inhibits the breakdown of glycogen to glucose, the conversion of amino acids or fats to glucose, so insulin is rightly called a hypoglycemic hormone.

Glucagon:
Glucagon is a polypeptide hormone. It is a potent hyperglycaemic hormone that acts on the liver and promotes the breakdown of glycogen to glucose (Glycogenolysis), synthesis of glucose from lactic acid and from non-carbohydrate molecules (gluconeogenesis).

Releases glucose from the liver cells, increasing the blood glucose levels. Since glucagon reduces the cellular uptake and utilisation of glucose it is called a hyperglycemic hormone. Prolonged hyperglycemia leads to the disorder called diabetes mellitus.

Question 6.
What is an exophthalmic goiter? What are its symptoms?
Answer:
This disease is caused due to hyper secretion of the thyroid.
Symptoms:

  • Enlargement of the thyroid gland
  • Increased BMR.
  • Elevated respiratory and excretory rates
  • Increased heart beat
  • High blood pressure
  • Increased body temperature
  • Protection of eye ball (Exophthalmic)
  • The weakness of eye muscles
  • Weight loss.

Question 7.
What is meant by negative feedback mechanism? Explain with an example.
Answer:
When the thyroxine level in the blood decreases it is sensed by the hypothalamus to release the thyroid releasing factor that induces the pituitary to secrete thyroid stimulating hormone that stimulates the thyroid to release thyroxine – when the thyroxine level in the blood increases TTH acts on both the pituitary and hypothalamus to inhibit TSH secretion. This is meant by negative feedback mechanism.
Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration 10

Question 8.
Why parathormone is considered as a hypercalcemic hormone.
Answer:

  • It increases the blood calcium level by stimulating osteo clasts to dissolve the bone matrix.
  • It enhances the reabsorption of calcium and also increases calcium adsorption by intestinal mucosal cells.
  • By all these action it increases the blood calcium level. Hence it is known as hypercalcemic hormone.

Question 9.
Write on Hyperthyroidism and Hypothyroidism?
Answer:
In infants, hypothyroidism causes cretinism. A cretin shows retarded skeletal growth, absence of sexual maturity, retarded mental ability, thick wrinkled skin, protruded enlarged tongue, bloated face, thick and short limbs occurs. The other symptoms are low BMR, slow pulse rate, subnormal body temperature and elevated blood cholesterol level.

Hyposecretion of the thyroid in adults causes myxoedema. It is otherwise called Gull’s disease. This disease is characterised by decreased mental activity, memory loss, slowness of movement, speech, and general weakness of body, dry coarse skin, scarce hair, puffy appearance, disturbed sexual function, low BMR, poor appetite, and subnormal body temperature.

Grave’s disease also called thyrotoxicosis or exophthalmic goiter. This disease is caused due to hypersecretion of the thyroid. It is characterised by enlargement of the thyroid gland, increases BMR (50% -100%), elevated respiratory and excretory rates, increased heartbeat, high BP, increases body temperature, protrusion of eyeball, and weakness of eye muscles and weight loss.

Simple goitre is also known as Endemic goitre. It is caused due to hyposecretion of thyroxine. The symptoms include enlargement of thyroid gland, fall in serum thyroxine level, increases TSH secretion.

Question 10.
Give an account of the actions of insulin.
Answer:

  • Insulin lowers the blood glucose level by increasing the uptake of glucose into the body cells.
  • It inhibits the conversion of amino acids or fat to glucose.
  • Insulin is called a hypoglycemic hormone.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 11.
Write on the disorders associated with parathryroid gland?
Answer:
Tetany is caused due to the hyposecretion of parathyroid hormone (PTH). Due to hyposecretion of PTH serum calcium level decreases (Hypocalcemia), as a result serum phosphate level increases. Calcium and phosphate excretion level decreses. Generalized convulsion, locking of jaws increased heart beat rate, increases body temperature, muscular spasm are the major symptoms of tetany. Hyperparathyroidism is caused due to excess PTH in blood. Demineralisation of bone, loss of muscle tone, general weakness, renal disorders are the symptoms of hyperparathyroidism.

Question 12.
a) What are the systems that regulate and co-ordinate the physiological functions of our body?
b) Give the meaning of the word “Hormone”.
c) What are the general characters of hormone?
Answer:
a) The systems that regulate and co-ordinate the physiological functions of our body are

  • Nervous or neural system
  • Endocrine system

b) The meaning of the word “Hormone”is “to excite”
c) General characters of hormones:

  • The endocrine system influences the metabolic activities through the hormones
  • These are chemical messengers released in to the blood and acts specifically on certain target organs or target tissues.
  • Hormones may speed up or slow down or alter the activity of the target organs.
  • Hormones secreted do not remain permanently in the blood.
  • After their function they are converted by the liver into inactive compounds and excreted by the kidneys.

Question 13.
Write a paragraph on different types of diabetes mellitus?
Answer:
Hyperglycaemia is otherwise known as Diabetes mellitus. Is caused due to reduced secretion of insulin. As the result, the blood glucose level is elevated. Diabetes mellitus is of two types, Type! Diabetes and Type II Diabetes. Type I diabetes is also known as Insulin-dependent diabetes, caused by the lack of insulin secretion due to illness or viral infections. Type II diabetes is also known as Non-Insulin dependent diabetes, caused due to reduced sensitivity to insulin, often called insulin resistance.

Symptoms of diabetes include polyuria (excessive urination), polyphagia (excessive intake of food), polydipsia (excessive consumption of liquids due to thirst), ketosis (the breakdown of fat into glucose results in accumulation of ketone bodies) in blood. Gluconeogenesis (Conversion of non-carbohydrate) also occurs in diabetes.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 14.
Give a diagrammatic sketch of the glandular system.
Answer:
Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration 11

Question 15.
Tabulate the major hypothalamic hormones and their functions.
Answer:

Hormones Functions
1. Thyrotropin-releasing hormone (TRH) Stimulates the secretion of TSH
2. Gonadotropin-releasing hormone(GnJRH) Stimulates the secretion of FSH
3. Corticotropin-releasing hormone (CRH) Stimulates the secretion of ACTH
4. Growth hormone-releasing hormone (GHRH) Stimulates the secretion of GH
5. Prolactin releasing hormone (PRH) Stimulates the secretion of Prolactin
6. Luteinizing hormone-releasing hormone (LHRH) Stimulates the secretion of LH
7. MSH releasing hormone Stimulates the secretion of MSH
8.Growth hormone-inhibiting hormone(GHIH) Inhibits the secretion of GH
9. Prolactin inhibiting hormone (PIEI) Inhibits the secretion of Prolactin
10. MSH inhibiting hormone Inhibits the secretion of MSH

Question 16.
Discuss the role of the hypothalamus and pituitary as a coordinated unit in maintaining the physiological process.
Answer:

  • Hypothalamus is a small cone-shaped structure that projects downward from the brain ending into the pituitary stalk.
  • It interlinks both the nervous system and endocrine system.
  • Hypothalamus contains a group of neuro secretary cells and it produces neuro transmitters which regulate the secretions of the pituitary.
  • The hormones produced by the hypothalamus act either as a releasing hormone or as an inhibitory hormone.
  • Though the pituitary gland is known as the master endocrine glands really it is in turn controlled by the hypothalamus.
  • The hypothalamus and pituitary gland are anatomically different they are interlinked and functioning as a co-ordinated unit in maintaining the physiological process. They can not functions as a separated unit.
  • The hypothalamic hypophyseal portal blood vessel allows hypothalamic hormones to control the anterior pituitary.
  • The nerve signal produced by the hypothalamic hypophyseal axis (nerve bundle) controls the posterior pituitary secretion.
  • Hypothalamus maintains homeostasis.
  • Maintains blood pressure, body temperature cardio, and fluid-electrolyte balance of the body it influences emotional responses.
  • The pituitary gland through its hormones performs various functions.

Question 17.
Give the classification of hormones based on their chemical nature?
Answer:

Class Chemical properties Example
Amines Small, water-soluble derived from tyrosine or tryptophan Adrenalin, nor adrenalin, melatonin, and thyroid hormone
Protein/ Peptides Water-soluble Insulin, glucagon, and pituitary hormones
Steroids Derived from cholesterol mostly lipid-soluble Cortisol, aldosterone, testosterone, oestrogen, progesterone.

Question 18.
Explain the structure of Testis?
Answer:

  • A pair of the testis is present in the scrotal sac of males.
  • The testis functions as a sex organ and also as an endocrine gland.
  • Testis composed of seminiferous tubules and Ley dig cells.
  • Lay dig cells secrete several male sex hormones collectively called Androgens.
  • The main male sex hormone is Testosterone.

Functions of Testosterone:

  1. Under the influence of FSH and LH, testosterone initiates the maturation of the male reproductive organ.
  2. The appearance of secondary sexual characters. Eg. Muscular growth, growth of facial and axillary hair, masculine voice, and male sexual behaviour.
  3. It enhances the total bone matrix and stimulating the process of spermatogenesis.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 19.
Give a brief account of the ovary.
Answer:

  • Females have a pair of ovaries located in the pelvic region of the abdomen.
  • It is composed of ovarian follicles and stromal tissue.
  • It produces the egg or ova.
  • It secretes the steroid hormones oestrogen and progesterone.

Functions:

  1. Oestrogen is responsible for the maturation of reproductive organs and the development of secondary sexual characters at puberty.
  2. Along with progesterone, oestrogen promotes breast development and initiates the menstrual cycle.
  3. Progesterone prepares the uterus for implantation of the fertilized ovum.
  4. It decreases the uterine contraction during pregnancy and stimulates the development of mammary glands and milk secretion.
  5. It is responsible for premenstrual changes in the uterus and for the formation of the placenta.

Question 20.
Explain the functions of hormones of the heart and kidney.
Answer:
Heart: The cardiocytes on the atrial walls secrete an important peptide hormone called atrial natriuretic factor (ANF)

Function: When blood pressure is increased ANF is secreted and causes dilation of the blood vessels to reduce the blood pressure.

Kidney: Three hormones are secreted by the kidneys. They are Renin, erythropoietin, and calcitriol.

Renin:

  • It is secreted by Juxta glomerular Cells (JGA).
  • It increases blood pressure when angiotensin is formed in the blood.

Erythropoietin:

  • It is also secreted by JGA.
  • Stimulates erythropoiesis ie formation of RBC in bone mawow.

Calcitriol:

  • It is secreted by proximal tubules of the nephron.
  • It is an active form of vitamin D3.
  • It promotes calcium and phosphorus absorption from the intestine and accelerates bone formation.

Question 21.
If you happen to see a man/lady with short stature how will you identify him?
Differentiate and give a reason for that disorder.
Answer:
The person may be suffering from either cretinism or Dwarfism.
The following symptoms may be observed in cretinism. It is due to the hypo-secretion of Thyroxine.

  • A cretin shows retarded skeletal growth.
  • Absence of sexual maturity.
  • Retarded mental ability.
  • Thick wrinkled skin.
  • Protruded enlarged tongue.
  • Bloated face.
  • Thick and short limb occur
  • Low BMR
  • Slow pulse rate.
  • Subnormal body temperature
  • Elevated blood cholesterol levels.

If the person shows the following symptom, he may have Dwarfism, it is due to hyposecretion of growth hormone.

  1. Skeletal growth and sexual maturity is arrested.
  2. They attain a maximum height of 4 feet only.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 22.
(i) Describe the structure of the pancreas.
(ii) Draw the diagram and marced it parts
(iii) How insulin controls blood sugar?
(iv) What is the role of glucagon in our body?
Answer:
i) Structure of pancreas:

  • Pancreas is a composite gland which performs both endocrine and exocrine functions.
  • It is located just below the stomach as a leaf-like structure.
  • It is composed of two major tissues such as acme and islets of Langerhans
  • Acme secretes digestive enzymes and the islets of Langerhans secretes hormones like insulin and glucagon.
  • Human pancreas has 1 -2 million islets of Langerhans.
  • In each islet about 60% cells are beta cells 25% cells are alpha cells and 10% are delta cells.
  • The alpha cells secrete glucagon the beta cells secrete insulin and delta cells secrete somatostatin.

ii) Structure of Islets of Langerhans (pancreas)
Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration 12

iii) Insulin control-blood sugar:-

  • Insulin is a peptide hormone and plays an important role in glucose homeostasis.
  • Its main effect is to lower blood glucose levels by increasing the uptake of glucose into the body cells
  • especially muscle and fat cells.
  • Insulin also inhibits the breakdown of glycogen to glucose, the conversion of amino acids or fats to glucose.
  • So insulin is rightly called a hypoglycemic hormone.
  • Reduced secretion of insulin leads to diabetes mellitus. As a result glucose level is elevated.
  • It is of two types. Type I. Diabetes and Type II Diabetes. Type I Diabetes is caused by lack of secretion of insulin due to illness or viral infection. Type II or Non-insulin-dependent diabetes caused due to reduced sensitivity to insulin.

iv) Role of Glucagon:

  • Glucagon is a polypeptide hormone.
  • It is a potent hyper glycemic hormone.
  • It acts on the liver and promotes the break down of glycogen to glucose (glycogenolysis)
  • It also promotes synthesis of glucose from lactic acid and from non-carbohydrate molecules is called Gluconeogenesis.
  • Glucogon releases glucose from the liver cell increasing the blood glucose levels.
  • Since glucagon reduces the cellular uptake and utilisation of glucose it is called a hyperglycemic hormone. Prolonged hyperglycemia leads to the disorder called diabetes mellitus.

Question 23.
Symptoms of diabetes
Answer:

  • Polyurea – excessive urination
  • Polyphagia – excessive intake of food
  • Poly dispsia – excessive consumption of liquids due to thirst.
  • Ketosis – breakdown of fat into glucose results in accumulation of ketone bodies in blood.
  • Gluconeogenesis also occur ie conversion of the non-carbohydrate form like amino acids and fat into glucose.

Question 24.
a) Write down the location and dimension of the pituitary gland?
b) Explain the internal structure of the pituitary gland?
c) Draw the diagram of the pituitary gland and label the parts.
Answer:
a. Location of pituitary gland:-

  • It is located in a depression called sella tursica a bony cavity of the sphenoid bone below the brain.
  • The pituitary gland means “to grow under”.
  • It is connected to the brain by a stalk called the infundibulum
  • Dimension:- It is about 1cm in diameter and 0. 5gm in weight.

b. Internal structure:-

  • The pituitary consists of two lobes, anterior glandular adenohypophysis and posterior neural neuro hypophysis.
  • Anatomically the anterior lobe or adenohypophysis has three lebesor zones namely pass intermedia, pass distalis and pass tuberalis.
  • The neurohypophysis is otherwise known as pars nervosa.
  • Embryonic origin:- The anterior lobe originates from the Embryonic invagination of pharyngeal epithelia called Rathke’s pouch.
  • The posterior lobe originates from the base of the brain as an outgrowth of the hypothalamus.

c. Hypothalamus and pituitary gland
Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration 13

Question 25.
Give a brief account of the hormones of the adenohypophysis.
Answer:
It secretes six hormones.
1. Growth Hormone:-

  • It is also known as somatotropic hormone (STH) or somatotropin
  • It is a peptide hormone.
  • It promotes the growth of all the tissues and metabolic processes of the body.
  • It influences the metabolism of carbohydrates, proteins, and lipids and increases the rate of biosynthesis in the cells.
  • It stimulates chondrogenesis (cartilage formation), osteogenesis (bone formation).
  • It helps in the retention of minerals like nitrogen and potassium, phosphorous, sodium, etc. in the body.

2. Thyroid Stimulating Hormone TSH or Thyrotropin:-

  • It is a glycoprotein.
  • It stimulates the thyroid gland to secrete Tri-iodothyronine (T3) and Thyroxine (T4).
  • TSH secretion is regulated by a negative feedback mechanism.
  • Its release from the anterior pituitary is induced by the thyrotropin-releasing hormone (TRH).
  • When thyroxine level in the blood increases TRH acts on both the pituitary and hypothalamus to inhibit TSH secretion.

3. Adreno Corticotropic Hormone (ACTH):-

  • It is a peptide hormone.
  • It stimulates the adrenal cortex to secrete glucocorticoids and mineral corticoids.
  • It stimulates melanin synthesis in melanocytes induces the release of fatty acids from adipose tissues and stimulates insulin secretion.
  • its secretion is regulated by a negative feedback mechanism.

4. Follicle Stimulating Hormone (FSH):-

  • It is a glycoprotein hormone.
  • It regulates the functions of the gonads.
  • In males, FSH along with androgens act on the germinal epithelium of seminiferous tubules and stimulates the production and release of sperms (Spermatogenesis).
  • In females, it acts on the ovaries and brings about the development and maturation of graffian follicles.

5. Luteinizing hormone (LH):-

  • It is a glycoprotein hormone.
  • It is also known as interstitial cell-stimulating hormone.
  • In females LH, along with FSH matures the ovarian follicles.
  • LH independently induces ovulation, maintains the corpus luteum and promotes synthesis and release of ovarian hormones.
  • In males, ICSH acts on interstitial cells of testes to produce the male sex hormone testosterone.

6. Luteo Tropic Hormone (LTH):-

  • It is a protein hormone.
  • It is also called luteotropin or lactogenic hormone or prolactin or mammotropin.
  • It stimulates milk secretion after childbirth.
  • Since it induces the corpus luteum hence named as a luteotropic hormone.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 26.
a) Name the hormones secreted by the neuro hypophysis?
b) Give a brief account of its functions?
Answer:
a. Neuro hypophysis secretes two hormones.

  1. Vasopressin or anti-diuretic hormone
  2. Oxytocin.

Vasopressin or Anti diuretic Hormone (ADH):-

  • It is a peptide hormone.
  • it promotes reabsorption of water and electrolytes by distal tubules of the nephron and thereby reduces the loss of water through urine.
  • Hence it is called an anti-diuretic hormone.
  • When released in large amounts it causes constriction of blood vessels and increases blood pressure.
  • ADH deficiency causes Diabetes insipidus which induces the production of a large amount of urine.

Oxytocin:-

  • It means quick birth.
  • It is a peptide hormone.

3. It stimulates vigorous contraction of the smooth muscles of the uterus during childbirth.
4. And it also stimulates the ejection of milk from the mammary glands.

b. Chemical nature:

  • The insulin hormone is a peptide hormone with 51 amino acids.
  • The molecular weight of insulin hormone is 5734 Dalton.
  • It consists of two chains A and B which are linked together by disulphide bridges formed between cystine residues.

Role of Insulin:

  • It increases uptake of glucose into body cells especially muscle and fat cells.
  • It inhibits the breakdown of glycogen to glucose, the conversion of amino acids or fats to glucose.
    Thus it decreases the blood glucose level and so insulin is rightly called as a hypoglycemic hormone.

c. How can this condition be reversed?

  • maintenance of normal body weight through adoption of nutritional habits ie. balanced diet and physical exercise.
  • Correction of over nutrition and obesity may reduce the risk of diabetes and its complications.
  • Alcohol and smoking should be avoided.
  • Control of high blood pressure elevated cholesterol and high triglyceride levels.

Question 27.
a) Why hormones are called chemical messengers?
b) Explain how the target organs are specifically fit for the action of hormones?
Answer:
a) Hormones are chemical messengers because they act as organic catalysts and co-enzymes to perform specific functions in the target organs.

b) Special features of target organs:

  • The target organs contain receptor molecules either on the surface or within the cell.
  • Although different hormones come in contact, only the cells that contain receptor molecules specific to the hormone are physiologically activated.
  • A single hormone may have multiple effects on a single target tissue or on different target tissues.
  • Many hormones exhibit long-term changes like growth, puberty, and pregnancy.
  • Serious deficiency or excess secretion of hormones leads to disorders.
  • Hormones coordinate different physiological mental activities and maintain homeostasis.

Question 28.
Draw the Endocrine gland is our body.
Answer:
Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration 14

Question 29.
Give an account on parathyroid hormones its hypo and hyper secretion deficiencies.
Answer:

  • Four tiny parathyroid glands are found in the posterior wall of the thyroid gland.
  • It is composed of Chief cells and oxyphil cell.
  • The chief cells secrete parathyroid hormone and the function of oxyphill cell are not known

Functions

  • It involves in calcium and phosphate.
  • It promotes the activation of vitamin D to increase calcium absorption by intestine.

Hyper secretion

  • Hyper parathyroidism causes demineral isation of calcium in bones.
  • Thus increasing the calcium and phosphate level in the blood.
  • PTH enhances the reabsorption of calcium and excretion of phosphate by the renal tubules.

Hypo secretion

  • Due to the hyposecretion of PTH serum calcium level decreases and the serum phosphate level increases.
  • Generalised convulsion occurs.

Samacheer Kalvi 11th Bio Zoology Guide Chapter 11 Chemical Coordination and Integration

Question 30.
a. Give an account of position of adrenal gland and it’s internal structure, b. List out the function of adrenal hormone.
Answer:
a) Position
A pair of adrenal glands are located at the anterior end of the kidney. Hence called supra renal glands.
b) Structure
The adrenal gland is composed of the outer cortex and an inner medulla.
The cortex consists of

  1. zona glomerulosa
  2. zona fasciculata
  3. zona reticularis.

1. zona glomerulosa
– secretes minerals corticoids

2. zona fasciculata
– secretes gluco corticoids

3. zona reticularis.
– secretes androgen and oestrogen.

b) Functions

  • Gluco corticoids stimulate gluco neogenesis.
  • Cortisolies involved in maintaining cardio vascular and kidney functions.
  • Cortisol stimulates RBC production.
  • Mineralocorticoids regulated the water and electrolyte balance of our body.
  • Androgen plays a role in hair growth in the axial region pubis and face during Puberty.

Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger

Tamilnadu State Board New Syllabus Samacheer Kalvi 11th Accountancy Guide Pdf Chapter 4 Ledger Text Book Back Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 11th Accountancy Solutions Chapter 4 Ledger

11th Accountancy Guide Ledger Text Book Back Questions and Answers

I. Choose the correct answer.

Question 1.
Main objective of preparing ledger account is to ………………..
(a) Ascertain the financial position
(b) Ascertain the profit or loss
(c) Ascertain the profit or loss and the financial position
(d) Know the balance of each ledger account
Answer:
(d) Know the balance of each ledger account

Question 2.
The process of transferring the debit and credit items from journal to ledger accounts is called ………….
(a) Casting
(b) Posting
(c) Journalising
(d) Balancing
Answer:
(b) Posting

Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger

Question 3.
J.F means
(a) Ledger page number
(b) Journal page number
(c) Voucher number
(d) Order number
Answer:
(b) Journal page number

Question 4.
The process of finding the net amount from the totals of debit and credit columns in a ledger is known as ……………
(a) Casting
(b) Posting
(c) Journalising
(d) Balancing
Answer:
(d) Balancing

Question 5.
If the total of the debit side of an account exceeds the total of its credit side, it means
(a) Credit balance
(b) Debit balance
(c) Nil balance
(d) Debit and credit balance
Answer:
(b) Debit balance

Question 6.
The amount brought into the business by the proprietor should be credited to
(a) Cash account
(b) Drawings account
(c) Capital account
(d) Suspense account
Answer:
(c) Capital account

II. Very Short Answer Type Questions

Question 1.
What is a ledger?
Answer:
A ledger account is a summary statement of all the transactions relating to a person, asset, liability, expense, or income which has taken place during a given period of time and it shows their net effect. From the transactions recorded in the journal, the ledger account is prepared. Ledger is known as the principal book of accounts.

Question 2.
What is meant by posting?
Answer:
The process of transferring the debit and credit items from the journal to the ledger accounts is called posting.

Question 3.
What is a debit balance?
Answer:

Question 4.
What is a credit balance?
Answer:
If the credit side of an account has higher total, the balancing figure is credit balance.

Question 5.
What is balancing of an account?
Answer:
Balancing means that the debit side and credit side amounts are totalled and the difference between the total of the two sides is placed in the amount column as ‘Balance c/d’ on the side having lesser total, so that the total of both debit and credit columns are equal.

When the total of the debit side is more than the total of credit side the difference is debit balance and is placed on the credit side as ‘By Balance c/d’. If the credit side total is more than the total of debit side, the difference is credit balance and is placed on the debit side as ‘To Balance c/d’.

III. Short Answer Questions

Question 1.
Distinguish between journal and ledger.
Answer:
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 1a

Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger

Question 2.
What is a ledger? Explain its utilities.
Answer:
1. Quick information about a particular account: Ledger account helps to get all information about a particular account like sales, purchases, machinery, etc., at a glance. For example, where there are several transactions with a debtor, the net amount due from a debtor can be known from the ledger account.

2. Control over business transactions: From the ledger balances extracted, a thorough analysis of account balances can be made which helps to have control over the business transactions.

3. Trial balance can be prepared: With the balances of ledger accounts, trial balance can be prepared to check the arithmetical accuracy of entries made in the journal and ledger.

4. Helps to prepare financial statements: From the ledger balances extracted, financial statements can be prepared for ascertaining net profit or loss and the financial position.

Question 3.
How is a posting made from, the journal to the ledger?
Answer:
The process of transferring the debit and credit items from the journal to the ledger accounts is called posting. The procedure of posting from journal to ledger is as follows:
1. Locate the ledger account that is debited in the journal entry. Open the respective account in the ledger, if already not opened. Write the name of the account in the top middle. If already opened, locate the account from the ledger index. Now entries are to be made on the debit side of the account.

2. Record the date of the transaction in the date column on the debit side of that account.

3. Record the name of the account credited in the journal with the prefix ‘To’ in particulars column.

4. Record the amount of the debit in the ‘amount column’.

5. Locate the ledger account that is credited in the journal entry. Open the respective account in the ledger, if already not opened. Write the name of the account in the top middle. If already opened, locate the account from the ledger index. Now entries are to be made on the credit side of the account. Record the date of the transaction in the date column. Record the name of the account debited in the journal entry in the particulars column with the prefix ‘By’ and write the amount in the Amount column.

Question 4.
Explain the procedure for balancing a ledger account.
Answer:
Following is the procedure for balancing an account:
1. The debit and credit columns of an account are to be totaled separately.

2. The difference between the two totals is to be ascertained.

3. The difference is to be placed in the amount column of the side having a lesser total. ‘Balance c/d’ is to be entered in the particulars column against the difference and in the date column, the last day of the accounting period is entered.

4. Now both the debit and credit columns are to be totaled and the totals will be equal. The totals of both sides are to be recorded in the same line horizontally. The total is to be distinguished from other figures by drawing lines above and below the amount.

5. The difference has to be brought down to the opposite side below the total. ‘Balance b/d’ is to be entered in the particulars column against the difference brought down and in the date column, the first day of the next accounting period is entered.

6. If the total on the debit side of an account is higher, the balancing figure is debit balance and if the credit side of an account has a higher total, the balancing figure is a credit balance. If the two sides are equal, that account will show nil balance.

IV. Exercises

Question 1.
Journalize the following transactions and post them to the ledger.
2016 Jan.1 Started business with cash – 10,000
5 Paid into bank – 5,000
7 Purchased goods from Ram for cash – 1,000
Answer:
Journal of Mr. X
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 1
Ledger Account
Cash Account
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 2
Bank Account
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 3

Question 2.
Give journal entries for the following transactions and post them to the ledger.
2015, March 1 Goods sold to Somu on credit – 5,000
7 Furniture purchased for cash – 300
15 Interest received – 1,800
Answer:
Journal of Mr.Y
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 4
Ledger Account
Samu Account
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 5
Furniture Account
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 6

Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger

Question 3.
Pass journal entries for the following transactions and post them to the ledger.
2017 Aug 1 Dharma started the business with cash – 70,000
6 Cash received from Ganesan – 10,000
10 Rent paid – 3000
20 Received commission from Anand – 5000
Answer:
Journal of Mr. Dharma
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 7
Dharma Capital Account
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 8
Rent Account
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 9

Question 4.
Record the following transactions in the journal of Banu and post them to the ledger.
2018, Sep 1 Commenced business with cash – 90,000
5 Rent received – 4,000
12 Purchased 6 tables from Gobu & Co. for cash – 6,000
Answer:
Journal of Mr. Banu
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 10
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 11

Question 5.
The following balances appeared in the books of Vinoth on Jan 1, 2018.
Assets: Cash Rs 40,000; Stock Rs 50,000; Amount due from Ram Rs 20,000
Machinery Rs 40,000 Liabilities: Amount due to Vijay Rs 10,000
Pass the opening journal entry and post them to Vinoth’s Capital account,
Answer:
Opening Entry
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 12

Question 6.
Prepare Furniture A/c from the following transactions
2016, Jan 1 Furniture in hand – 2,000
1 Purchased furniture for cash – 4,000
30 Sold furniture – 400
Answer:
Furniture Account
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 13

Question 7.
The following balances appeared in the books of Kumaran on April 1, 2017.
Assets: Cash Rs 1,00,000; Stock Rs 40,000; Amount due from Rohit Rs 10,000;
Furniture Rs 10,000;
Liabilities: Amount due to Anusha Rs 40,000;
Kumaran’s capital Rs 1,20,000
Find the capital and show the ledger posting for the above opening balances.
Answer:
Opening Entry
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 14
Stock Account
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 15
Furniture Account
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 16
Kumaran Account
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 17

Question 8.
Give journal entries and post them to the cash account.
2016, June 1 Commenced business with cash – 1,10,000
10 Introduced additional capital – 50,000
28 Withdrawn for personal use – 20,000
Answer:
Journal Entry
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 18

Question 9.
Give journal entries from the following transactions of Mohit, dealing in Textiles, and post them to the ledger.
2014 Aug 1 Commenced business with cash – 1,10,000
7 Opened bank account with SBI – 50,000
3 Purchased furniture for cash – 20,000
Answer:
Journal of Mohit
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 19
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 20
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 21

Question 10.
Give journal entries for the following transactions and post them to the ledger.
2016, sep 1 Commenced business with cash – 80,000
7 Bought goods for cash from Roopan – 10,000
10 Purchased goods from Hema on credit – 42,000
22 Goods returned to Hema – 2,000
23 Cash paid to Hema – 10,000
Answer:
Journal of Entry Mr. Y
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 22
Ledger Account
Cash Account
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 23
Purchases Account
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 24

Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger

Question 11.
Give Journal entries for the following transactions and post them to Cash A/c and Sales A/c.
2017, Aug 10 Sold goods and cheque received but not deposited – 30,000
14 Sold goods on credit to Gopi – 12,000
20 Received cash from Gopi – 12,000
Answer:
Journal of Entry Mr. Y
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 25
Cash Account
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 26

Question 12.
Journalise the transactions given below and post them to the ledger.
2017 Oct. 18 Paid trade expenses – 1,000
25 Bought postage stamps – 100
30 Commission received – 6,000
30 Rent paid – 4,000
Answer:
Journal of Entries
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 27
Cash Account
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 28
Commission Received Account
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 29

Question 13.
Journalize the following transactions and prepare ledger accounts.
2015, Feb 1 Sold goods for cash – 5,000
2 Purchased goods from Kumar on credit – 4,000
5 Sold goods to Prabu on credit – 8,000
12 Received cash from Prabu – 1,200
20 Paid to Kumar – 2,000
25 Paid salary – 3,000
Answer:
Journal Entry
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 30
Sales Account
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 31
Prabhu Account
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 32
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 33

Question 14.
Enter the following transactions in the books of Ganesan and post them into the ledger.
2017, Oct 1 Started business with cash – 25,000
5 Deposited into bank – 12,500
10 Purchased furniture and payment by cheque – 2,000
15 Goods purchased for cash – 5,000
19 Sold goods to Vasu on credit – 4,000
22 Goods worth Rs 500 taken for personal use
Answer:
Journal of Ganesan
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 34
Ledger Account
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 35
Bank Account
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 36
Vasu Account
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 37

Question 15.
Journalize the following transactions in the books of Arun and post them to ledger accounts
accounts.
2017, Dec 1 Arun started his business with cash – 10,000
3 Bought goods for cash – 1,500
8 Sold goods to Krishna on credit – 4,000
14 Purchased goods from Govind on credit – 2,000
25 Received cash from Krishna – 3,000
28 Cash paid to Govind – 1,000
Answer:
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 38
Ledger Account
Cash Account
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 39
Purchases Account
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 40
Sales Account
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 41

Question 16.
Journalize the following transactions and post them to the ledger in the books of Raja.
2018, Mar 1 Sold goods to Senthil for cash – 9,000
5 Sold goods to Murali on credit – 500
9 Cash sales – 6,000
18 Bought goods from Mani on credit – 3,200
23 Received Rs 4,000 from Murali in full settlement of his account
Answer:
Journal of Raja
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 42
Sales Account
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 43
Purchases Account
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 44

Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger

Question 17.
Journalize the following transactions and post them to the ledger.
2017, July 1 Cash in hand – 50,000
5 Goods purchased by cash – 30,000
7 Insurance paid – 2,500
10 Machinery purchased for cash – 9,000
15 Interest received – 2,000
18 Goods sold for cash – 7,000
Answer:
Journal of Entry of Mr. Y
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 45
Purchases Account
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 46
Machinary Account
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 47

Question 18.
Journalize the following transactions in the books of Vasu and post them to ledger accounts.
2017, Nov 1 Cash in hand Rs 1,00,000; Cash at bank: Rs 30,000
2 Vasu sold goods to Jothi for Rs 25,000 against a cheque and deposited the same in the bank
4 Received as commission Rs 5,000
8 Bank paid Rs 15,000 directly for the insurance premium of Vasu.
15 Cash deposited into bank Rs 30,000
20 Cash withdrawn from bank for personal use Rs 45,000.
Answer:
Journal of Mr. Vasu
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 48
Ledger Account
Cash Account
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 49
Bank Account
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 50
Commission Received Account
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 51

Question 19.
Prepare Anand’s account from the following details.
2017, July 1 Credit balance of Anand’s A/c – 4,000
15 Amount paid to Anand – 2,000
18 Goods purchased from Anand on credit – 8,000
20 Paid to Anand – 3,960
Discount allowed by him – 40
25 Goods purchased from Anand – 5,000
Answer:
Ledger Account
Dr. Anand’s Account
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 52

Question 20.
Prepare a Sales account from the following transactions.
2018, Jan 1 Sold goods to Sam – 4,000
4 Sold goods to Suresh – 2,500
11 Sold goods to Joy – 8,000
17 Sold goods to Rajan – 3,000
Answer:
Ledger Account
Sales Account
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 53

Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger

Question 21.
Show the direct ledger postings for the following transactions:
2017, June 1 Raja commenced business with cash Rs 50,000,
6 Sold goods for cash Rs 8,000
8 Sold goods to Devi on credit Rs 9,000
15 Goods purchased for cash Rs 4,000
20 Goods purchased from Shanthi on credit Rs 5,000
Answer:
Ledger Account
Cash Account
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 54
Sales Account
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 55
Purchases Account
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 56

Question 22.
Show the direct ledger postings for the following transactions:
2017, July 1 Shankar commenced business with a cash of Rs 1,00,000
5 Sold goods for cash Rs 10,000
9 Wages paid Rs 6,000
19 Salaries paid Rs 8,000
20 Advertisement expenses paid Rs 4,000
Answer:
Ledger Account
Cash Account
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 57
Shankar Capital Account
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 58
wages Account
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 59

11th Accountancy Guide Ledger Additional Important Questions and Answers

I. Choose the correct answer.

Question 1.
………………. is known as the principal book of accounts.
(a) Journal
(b) Ledger
(c) Trial balance
(d) Transaction
Answer:
(b) Ledger

Question 2.
Personal and real accounts are:
(a) closed
(b) Balanced
(c) closed and transferred
(d) opening
Answer:
(b) Balanced

Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger

Question 3.
………………. accounts give the net amount due to creditor and the net amount due from debtors.
(a) Real
(b) Personal
(c) Nominal
(d) Ledger
Answer:
(b) Personal

Question 4.
Posting on the credit side of an account is written as
(a) To
(b) By
(c) Being
(d) Both (a) and (b)
Answer:
(b) By

Question 5.
The net position of an account can be ascertained from ……………….
(a) Journal
(b) Ledger
(c) Trial balance
(d) Balance sheet
Answer:
(b) Ledger

Question 6.
A nominal account having a credit balance represents
(a) income / gain
(b) expenses / losses
(c) assets
(d) liabilities
Answer:
(a) income / gain

Question 7.
When a journal entry has more than one debit or more than one credit or both, it is called ……………….
(a) Compound entry
(b) Single entry
(c) Journal entry
(d) Ledger entry
Answer:
(a) Compound entry

Question 8.
Real accounts always show
(a) debit balances
(b) credit balances
(c) nill balance
(d) Both (a) and (b)
Answer:
(a) debit balances

Question 9.
Total of debit > Total of credit =
(a) Debit balance
(b) Credit balance
(c) Nil balance
(d) Trial balance
Answer:
(a) Debit balance

Question 10.
When the total of debits and credits are equal, it represents
(a) debit balance
(b) credit balance
(c) nil balance
(d) opening balance
Answer:
(c) nil balance

Question 11.
The balances of personal and real accounts are shown in the
(a) profit and loss account
(b) balance sheet
(c) trading account
(d) both (a) and (b)
Answer:
(b) balance sheet

Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger

Question 12.
If the total of the credit side of an account exceeds the total of its debit side, it means
(a) Credit balance
(b) Debit balance
(c) Nil balance
(d) Debit and credit balance
Answer:
(a) Credit balance

Question 13.
The closing balance is the next year’s
(a) debit balance
(b) credit balance
(c) nil balance
(d) opening balance
Answer:
(d) opening balance

Question 14.
The ledger account is prepared in format.
(a) T
(b) D
(c) C
(d) U
Answer:
(a) T

Question 15.
The process of recording business transactions in a chronological order is called ……………
(a) Recording
(b) Posting
(c) Journalizing
(d) Classifying
Answer:
(c) Journalizing

Question 16.
Which one of the following is known as the king of all books of accounts?
(a) Recording
(b) Posting
(c) Journalizing
(d) Classifying
Answer:
(c) Journalizing

Question 17.
A decrease in the provision for doubtful debts would result in
(a) Increase in liability
(b) Decrease in liability
(c) Decrease in the net profit
(d) Increase in the net profit
Answer:
(d) Increase in the net profit

Question 18.
The discount which is calculated on the list price of the goods is called .
(a) Cash discount
(b) Rebate
(c) Trade discount
(d) Discount
Answer:
(c) Trade discount

Question 19.
Merchandise stolen by someone should be debited to …………..
(a) Sales account
(b) Purchases account
(c) Loss by theft account
(d) None of the above
Answer:
(c) Loss by theft account

Question 20.
The owner of the business takes Rs.100 cash and goods costing Rs.200 for his family. The proper journal entry for this transaction is called ……………..
(a) drawing > debit; Cash > Credit; Purchases > Credit
(b) Drawing > debit; Cash > Credit; merchandise > credit
(c) Drawing > debit; Cash > credit; Sales > credit
(d) cash > debit; Purchases > debit; drawings > credit
Answer:
(a) drawing > debit; Cash > Credit; Purchases > Credit

II. Very Short Answer Type Questions

Question 1.
What is Nil balance?
Answer:
If the two sides are equal, that account will show nil balance.

Question 2.
What are the steps involved in posting the opening entry?
Answer:
Step 1:
The items debited in the opening entry are entered on the debit side of respective accounts. The words ‘To Balance b/d’ are written in the particulars column with respective amounts in the amount column, date being the first day of the accounting period.

Step 2:
The items credited in the opening entry are entered on the credit side of respective accounts. The words ‘By Balance b/d’ are written in the particulars column with respective amounts in the amount column, date being the first day of the accounting period.

Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger

Question 3.
Indicate the nature of normal balance in the following accounts.
Answer:
a. Cash – Debit balance
b. Creditors – Credit balance
c. Sales – Credit balance
d. Furniture – Debit balance
e. Commission received – Credit balance
f. Debtors – Debit balance
g. Purchases – Debit balance
h. Capital – Credit balance
i. Discount earned – Credit balance
j. Computer – Debit balance

Question 4.
Define ledger.
Answer:
According to L.C. Cropper, ‘the book which contains a classified and permanent record of all the transactions of a business is called the Ledger’.

Question 5.
What is compound journal entry?
Answer:
When a journal entry has more than one debit or more than one credit or both, it is called a compound entry.

III. Additional Sums

Question 1.
Prepare cash account A/c from the following transactions.
2018 Jan. 1 Commenced business with cash Rs 62,000
2 Good purchased for cash Rs 12,000
10 Cash sales Rs 10,000
12 Wages paid Rs 4,000
25 Furniture purchased for cash Rs 6,000
Answer:
Ledger Account
Cash Account
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 60

Question 2.
Prepare a sales A/c from the following transaction.
2018 Feb. 1 Cash sales – 5,000
4 Sold goods to Suresh – 4,000
8 Sold goods to Mohan – 8,000
12 Sold goods for cash – 3,000
Answer:
Ledger Account
Sales Account
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 61

Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger

Question 3.
Prepare Rangasamy A/c for the following transaction.
2017 Aug. 17 Goods purchased from Rangasamy Rs. 20,000
19 Goods returned to Rangasamy Rs. 5,000
31 Settles Rangasamy’s account
Answer:
Ledger Account
Rangasamy Account
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 62

Question 4.
Prepare Chitra account from the following transaction.
2018 March. 18 Sold goods to Chitra Rs. 1,26,000
24 Chitra returned goods Rs. 6,000
28 Chitra settled her account
Answer:
Chitra Account
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 63

Question 5.
Journalise the following transaction and post them to ledger in the book of Mr. Raja.
2018, Jan. 1 Started business with cash Rs 3,00,00
2 Opening bank account by deposition Rs 2,00,000
5 Purchased goods for cash Rs 10,000
15 Cash sales Rs 5,000
22 Purchased goods from X and Co. for Rs 15,000 and the payment is made through net banking
25 Sold goods for Y and Co. for Rs 30,000 and the payment is received thought NEET
Answer:
Journal of Mr. Raja
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 64
Ledger Account
Cash Account
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 65
Raja Capital Account
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 66
Purchases Account
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 67

Question 6.
Post the following Journal into Ledger of Thiru. Gowri Shankar.
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 68
Answer:
Ledger Account
Cash Account
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 69
Sayeed Account
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 70
David Account
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 71

Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger

Question 7.
Show the sivect ledger positions for the following transaction.
2018, May. 1 Commenced business with cash Rs 1,50,000
2 Sold goods for cash Rs 50,000
5 Purchases goods for cash Rs 25,000
25 Salaries paid Rs 15,000
30 Wages paid Rs 10,000
Answer:
Ledger Account
Cash Account
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 72
Capital Account
Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger 73

Samacheer Kalvi 11th Accountancy Guide Chapter 4 Ledger