Samacheer Kalvi 9th Maths Guide Chapter 3 Algebra Ex 3.8

Students can download Maths Chapter 3 Algebra Ex 3.8 Questions and Answers, Notes, Samacheer Kalvi 9th 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 9th Maths Solutions Chapter 3 Algebra Ex 3.8

Synthetic division calculator. This calculator divides two polynomials using synthetic division.

Question 1.
Factorise each of the following polynomials using synthetic division:
(i) x3 – 3x² – 10x + 24
Solution:
p(x) – x3 – 3x² – 10x + 24
p(1) = 13 – 3(1)² – 10(1) + 24
= 1 – 3 – 10 + 24
= 25 – 13
≠ 0
x – 1 is not a factor

p(-1) = (-1)3 – 3(-1)² – 10(-1) + 24
= – 1 – 3(1) + 10 + 24
= -1 – 3 + 10 + 24
= 34 – 4
= 30
≠ 0
x + 1 is not a factor

p(2) = 23 – 3(2)² – 10(2) + 24
= 8 – 3(4) – 20 + 24
= 8 – 12 – 20 + 24
= 32 – 32
= 0
∴ x – 2 is a factor
Samacheer Kalvi 9th Maths Guide Chapter 3 Algebra Ex 3.8 1
x² – x – 12 = x² – 4x + 3x – 12
Samacheer Kalvi 9th Maths Guide Chapter 3 Algebra Ex 3.8 2
= x(x – 4) + 3 (x – 4)
= (x – 4) (x + 3)
∴ The factors of x3 – 3x² – 10x + 24 = (x – 2) (x – 4) (x + 3)

Samacheer Kalvi 9th Maths Guide Chapter 3 Algebra Ex 3.8

(ii) 2x3 – 3x² – 3x + 2
Solution:
p(x) = 2x3 – 3x² – 3x + 2
P(1) = 2(1)3 – 3(1)² – 3(1) + 2
= 2 – 3 – 3 + 2
= 2 – 6
= -4
≠ 0
x – 1 is not a factor

P(-1) = 2(-1)3 – 3(-1)² – 3(-1) + 2
= -2 – 3 + 3 + 2
= 5 – 5
= 0
∴ x + 1 is a factor
Samacheer Kalvi 9th Maths Guide Chapter 3 Algebra Ex 3.8 3
2x² – 5x + 2 = 2x² – 4x – x + 2
Samacheer Kalvi 9th Maths Guide Chapter 3 Algebra Ex 3.8 4
= 2x(x – 2) – 1 (x – 2)
= (x – 2) (2x – 1)
∴ The factors of 2x3 – 3x² – 3x + 2 = (x + 1) (x – 2) (2x – 1)

Samacheer Kalvi 9th Maths Guide Chapter 3 Algebra Ex 3.8

(iii) – 7x + 3 + 4x3
Solution:
p(x) = – 7x + 3 + 4x3
= 4x3 – 7x + 3
P(1) = 4(1)3 – 7(1) + 3
4 – 7 + 3
= 7 – 7
= 0
∴ x – 1 is a factor
Samacheer Kalvi 9th Maths Guide Chapter 3 Algebra Ex 3.8 5
4x² + 4x – 3 = 4x² + 6x – 2x – 3
Samacheer Kalvi 9th Maths Guide Chapter 3 Algebra Ex 3.8 6
= 2x(2x + 3) – 1 (2x + 3)
= (2x + 3) (2x – 1)
∴ The factors of – 7x + 3 + 4x3 = (x – 1) (2x + 3) (2x – 1)

Samacheer Kalvi 9th Maths Guide Chapter 3 Algebra Ex 3.8

(iv) x3 + x² – 14x – 24
Solution:
p(x) = x3 + x² – 14x – 24
p(1) = (1)3 + (1)2 – 14 (1) – 24
= 1 + 1 – 14 – 24
= -36
≠ 0
x + 1 is not a factor.

p(-1) = (-1)3 + (-1)² – 14(-1) – 24
= -1 + 1 + 14 – 24
= 15 – 25
≠ 0
x – 1 is not a factor.

p(2) = (-2)3 + (-2)2 – 14 (-2) – 24
= -8 + 4 + 28 – 24
= 32 – 32
= 0
∴ x + 2 is a factor
Samacheer Kalvi 9th Maths Guide Chapter 3 Algebra Ex 3.8 7
x² – x – 12 = x² – 4x + 3x – 12
Samacheer Kalvi 9th Maths Guide Chapter 3 Algebra Ex 3.8 8
= x(x – 4) + 3 (x – 4)
= (x – 4) (x + 3)
This (x + 2) (x + 3) (x – 4) are the factors.
x3 + x2 – 14x – 24 = (x + 2) (x + 3) (x – 4)

Samacheer Kalvi 9th Maths Guide Chapter 3 Algebra Ex 3.8

(v) x3 – 7x + 6
Solution:
p(x) = x3 – 7x + 6
P( 1) = 13 – 7(1) + 6
= 1 – 7 + 6
= 7 – 7
= 0
∴ x – 1 is a factor
Samacheer Kalvi 9th Maths Guide Chapter 3 Algebra Ex 3.8 9
x² + x – 6 = x² + 3x – 2x – 6
Samacheer Kalvi 9th Maths Guide Chapter 3 Algebra Ex 3.8 10
= x(x + 3) – 2 (x + 3)
= (x + 3) (x – 2)
This (x – 1) (x – 2) (x + 3) are factors.
∴ x3 – 7x + 6 = (x – 1) (x – 2) (x + 3)

Samacheer Kalvi 9th Maths Guide Chapter 3 Algebra Ex 3.8

(vi) x3 – 10x² – x + 10
p(x) = x3 – 10x2 – x + 10
= 1 – 10 – 1 + 10
= 11 – 11
= 0
∴ x – 1 is a factor
Samacheer Kalvi 9th Maths Guide Chapter 3 Algebra Ex 3.8 11
x2 – 9x – 10 = x2 – 10x + x – 10
Samacheer Kalvi 9th Maths Guide Chapter 3 Algebra Ex 3.8 12
= x(x – 10) + 1 (x – 10)
= (x – 10) (x + 1)
This (x – 1) (x + 1) (x – 10) are the factors.
∴ x3 – 10x2 – x + 10 = (x – 1) (x – 10) (x + 1)

Samacheer Kalvi 9th Maths Guide Chapter 3 Algebra Ex 3.8

Samacheer Kalvi 9th Maths Guide Chapter 8 Statistics Ex 8.1

Students can download Maths Chapter 8 Statistics Ex 8.1 Questions and Answers, Notes, Samacheer Kalvi 9th 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 9th Maths Solutions Chapter 8 Statistics Ex 8.1

Question 1.
In a week, temperature of a certain place is measured during winter are as follows 26°C, 24°C, 28°C, 31°C, 30°C, 26°C, 24°C. Find the mean temperature of the week.
Solution:
Mean temperature of the week
Samacheer Kalvi 9th Maths Guide Chapter 8 Statistics Ex 8.1 1
= 27°C
Mean temperature of the week 27° C

Samacheer Kalvi 9th Maths Guide Chapter 8 Statistics Ex 8.1

Question 2.
The mean weight of 4 members of a family is 60 kg. Three of them have the weight 56 kg, 68 kg and 72 kg respectively. Find the weight of the fourth member.
Solution:
Weight of 4 members = 4 × 60 kg
= 240 kg
Weight of three members = 56 kg + 68 kg + 72 kg
= 196 kg
Weight of the fourth member = 240 kg – 196 kg
= 44 kg

Median Calculator is used to compute and display the median of a list of given values or a set of data.

Samacheer Kalvi 9th Maths Guide Chapter 8 Statistics Ex 8.1

Question 3.
In a class test in mathematics, 10 students scored 75 marks, 12 students scored 60 marks, 8 students scored 40 marks and 3 students scored 30 marks. Find the mean of their score.
Solution:
Total marks of 10 students = 10 × 75 = 750
Total marks of 12 students = 12 × 60 = 720
Total marks of 8 students = 8 × 40 = 320
Total marks of 3 students = 3 × 30 = 90
Total marks of (10 + 12 + 8 + 3) 33 students
= 750 + 720 + 320 + 90
= 1880
Mean of marks = \(\frac{1880}{33}\)
= 56.97 (or) 57 approximately
Aliter:
Total number of students = 10+12 + 8 + 3
= 33
Mean of their marks
Samacheer Kalvi 9th Maths Guide Chapter 8 Statistics Ex 8.1 2
= 56.97 (or) 57 approximately

Samacheer Kalvi 9th Maths Guide Chapter 8 Statistics Ex 8.1

Question 4.
In a research laboratory scientists treated 6 mice with lung cancer using natural medicine. Ten days later, they measured the volume of the tumor in each mouse and given the results in the table.
Samacheer Kalvi 9th Maths Guide Chapter 8 Statistics Ex 8.1 3
find the mean.
Solution:
Samacheer Kalvi 9th Maths Guide Chapter 8 Statistics Ex 8.1 4
\(\bar { x }\) = \(\frac{Σfx}{Σf}\)
= \(\frac{2966}{21}\)
= 141.238
= 141.24
The Arithmetic mean = 141.24 mm³

Samacheer Kalvi 9th Maths Guide Chapter 8 Statistics Ex 8.1

Question 5.
If the mean of the following data is 20.2, then find the value of p.
Samacheer Kalvi 9th Maths Guide Chapter 8 Statistics Ex 8.1 5
Solution:
Samacheer Kalvi 9th Maths Guide Chapter 8 Statistics Ex 8.1 6
\(\bar { x }\) = \(\frac{Σfx}{Σf}\)
20.2 = \(\frac{610+20p}{30+p}\)
610 + 20 p = 20.2 (30 + p)
610 + 20 p = 606 + 20.2 p
610 – 606 = 20.2 p – 20 p
4 = 0.2 p
p = \(\frac{4}{0.2}\)
= \(\frac{4×10}{2}\)
= 20
The value of p = 20

Question 6.
In the class, weight of students is measured for the class records. Calculate mean weight of the class students using direct method.
Samacheer Kalvi 9th Maths Guide Chapter 8 Statistics Ex 8.1 7
Solution:
Samacheer Kalvi 9th Maths Guide Chapter 8 Statistics Ex 8.1 8
Arithmetic mean \(\bar { x }\) = \(\frac{Σfx}{Σf}\)
= \(\frac{2010}{50}\)
= 40.2
Arithmetic mean = 40.2

Samacheer Kalvi 9th Maths Guide Chapter 8 Statistics Ex 8.1

Question 7.
Calculate the mean of the following distribution using Assumed Mean Method.
Samacheer Kalvi 9th Maths Guide Chapter 8 Statistics Ex 8.1 9
Solution:
Assumed Mean (A) = 25
Samacheer Kalvi 9th Maths Guide Chapter 8 Statistics Ex 8.1 10
Arithmetic mean (\(\bar { x }\)) = A+\(\frac{Σfd}{Σf}\)
= 25 + \(\frac{270}{63}\)
= 25 + 4. 29
Assumed Mean = 29.29

Samacheer Kalvi 9th Maths Guide Chapter 8 Statistics Ex 8.1

Question 8.
Find the Arithmetic Mean of the following data using Step Deviation Method:
Samacheer Kalvi 9th Maths Guide Chapter 8 Statistics Ex 8.1 11
Solution:
Assumed Mean (A) = 32
Samacheer Kalvi 9th Maths Guide Chapter 8 Statistics Ex 8.1 12
Arithmetic mean = A+\(\frac{Σfd}{Σf}\) × c
= 32 + (\(\frac{-77.5}{105}\)×4)
= 32 – 2.95
= 29.05
Arithmetic mean = 29.05

Samacheer Kalvi 9th Maths Guide Chapter 3 Algebra Ex 3.15

Students can download Maths Chapter 3 Algebra Ex 3.15 Questions and Answers, Notes, Samacheer Kalvi 9th 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 9th Maths Solutions Chapter 3 Algebra Ex 3.15

Multiple Choice Questions.

Question 1.
If x3 + 6x2 + kx + 6 is exactly divisible by x + 2, then k = 2
(a) 6
(b) -7
(c) -8
(d) 11
Solution:
(d) 11
Hint:
p(x) = x3 + 6x2 + kx + 6
Given p(-2) = 0
(-2)3 + 6(-2)2 + k(-2) + 6 = 0
-8 + 24 – 2k + 6 = 0
22 – 2k = 0
k = \(\frac{22}{2}\)
= 11

Question 2.
The root of the polynomial equation 2x + 3 = 0 is…….
(a) \(\frac{1}{3}\)
(b) –\(\frac{1}{3}\)
(c) –\(\frac{3}{2}\)
(d) –\(\frac{2}{3}\)
Solution:
(c) –\(\frac{3}{2}\)
Hint:
2x + 3 = 0
2x = – 3 ⇒ x = –\(\frac{3}{2}\)

Online Polynomial Root Calculator. This online tool calculates the roots of a polynomial. I use this tool to calculate the roots to plot Bode diagrams.

Samacheer Kalvi 9th Maths Guide Chapter 3 Algebra Ex 3.15

Question 3.
The type of the polynomial 4 – 3x3 is ……..
(a) constant polynomial
(b) linear polynomial
(c) quadratic polynomial
(d) cubic polynomial
Solution:
(d) cubic polynomial

Question 4.
If x51 + 51 is divided by x + 1, then the remainder is …….
(a) 0
(b) 1
(c) 49
(d) 50
Solution:
(d) 50
Hint:
p(x) = x51 + 51
p(-1)= (-1)51 + 51
= -1 + 51
= 50

Question 5.
The zero of the polynomial 2x + 5 is ……..
(a) \(\frac{5}{2}\)
(b) –\(\frac{5}{2}\)
(c) \(\frac{2}{5}\)
(d) –\(\frac{2}{5}\)
Solution:
(b) –\(\frac{5}{2}\)
Hint:
2x + 5 = 0 ⇒ 2x = -5 ⇒ x = –\(\frac{5}{2}\)

Samacheer Kalvi 9th Maths Guide Chapter 3 Algebra Ex 3.15

Question 6.
The sum of the polynomials p(x) = x3 – x2 – 2, q(x) = x2 – 3x + 1
(a) x3 – 3x – 1
(b) x3 + 2x2 – 1
(c) x3 – 2x2 – 3x
(d) x3 – 2x2 + 3x – 1
Solution:
(a) x3 – 3x – 1
Hint:
p(x) + q(x) = (x3 – x2 – 2) + (x2 – 3x + 1) = x3 – x2 – 2 + x² – 3x + 1
= x³ – 3x – 1

Question 7.
Degree of the polynomial (y³ – 2) (y³ + 1) is
(a) 9
(b) 2
(c) 3
(d) 6
Solution:
(d) 6
(y³ – 2) (y³ + 1) = y6 + y³ – 2y³ – 2
= y6 – y³ – 2

Question 8.
Let the polynomials be
(A) -13q5 + 4q² + 12q
(B) (x² + 4)(x² + 9)
(C) 4q8 – q6 + q²
(D) –\(\frac{5}{7}\) y12 + y³ + y5.
Then ascending order of their degree is
(a) A, B, D, C
(b) A, B, C, D
(c) B, C, D, A
(d) B, A, C, D
Solution:
(d) B, A, C, D

Samacheer Kalvi 9th Maths Guide Chapter 3 Algebra Ex 3.15

Question 9.
If p(a) = 0 then (x – a) is a …….. of p(x)
(a) divisor
(b) quotient
(c) remainder
(d) factor
Solution:
(d) factor

Question 10.
Zeros of (2 – 3x) is ……..
(a) 3
(b) 2
(c) \(\frac{2}{3}\)
(d) \(\frac{3}{2}\)
Solution:
(c) \(\frac{2}{3}\)

Question 11.
Which of the following has x -1 as a factor?
(a) 2x – 1
(b) 3x – 3
(c) 4x – 3
(d) 3x – 4
Solution:
(b) 3x – 3

Samacheer Kalvi 9th Maths Guide Chapter 3 Algebra Ex 3.15

Question 12.
If x – 3 is a factor of p(x), then the remainder is ……..
(a) 3
(b) -3
(c) p(3)
(d) p(-3)
Solution:
(c) p(3)

Question 13.
(x +y)(x² – xy + y²) is equal to ……..
(a) (x + y)³
(b) (x – y)³
(c) x³ + y³
(d) x³ – y³
Solution:
(c) x³ + y³

Question 14.
(a + b – c)² is equal to ……..
(a) (a – b + c)²
(b) (-a – b + c)²
(c) (a + b + c)²
(d) (a – b – c)²
Solution:
(b) (-a – b + c)²
Hint:
(a + b – c)² = a² + b² + c² + 2ab – 2bc – 2ac
(- a – b + c)² = a² + b² + c² + 2ab – 2bc – 2ac
(OR)
(- a – b + c)² = (-1)² (a + b + c)² (taking – 1 as common)
= (a + b – c)²

Samacheer Kalvi 9th Maths Guide Chapter 3 Algebra Ex 3.15

Question 15.
In an expression ax² + bx + c the sum and product of the factors respectively ……..
(a) a, bc
(b) b, ac
(c) ac, b
(d) bc, a
Solution:
(b) b, ac

Question 16.
If (x + 5) and (x – 3) are the factors of ax² + bx + c, then values of a, b and c are ………
(a) 1, 2, 3
(b) 1, 2, 15
(c) 1, 2, -15
(d) 1, -2, 15
Solution:
(c) 1, 2, -15
Hint:
(x + 5) (x – 3) = x² + (5 – 3) x + (5) (-3)
= x² + 2x – 15
compare with ax² + bx + c
a = 1, b = 2 and c = -15

Question 17.
Cubic polynomial may have maximum of ……… linear factors.
(a) 1
(b) 2
(c) 3
(d) 4
Solution:
(c) 3

Samacheer Kalvi 9th Maths Guide Chapter 3 Algebra Ex 3.15

Question 18.
Degree of the constant polynomial is ……..
(a) 3
(b) 2
(c) 1
(d) 0
Solution:
(d) 0

Question 19.
Find the value of m from the equation 2x + 3y = m. If its one solution is x = 2 and y = -2.
(a) 2
(b) -2
(c) 10
(d) 0
Solution:
(b) – 2
Hint:
The equation is 2x + 3y = m
Substitute x – 2 and y = -2 we get
2(2) + 3(-2) = m ⇒ 4 – 6 = m ⇒ -2 = m

Question 20.
Which of the following is a linear equation?
(a) x + \(\frac{1}{2}\) = 2
(b) x (x – 1) = 2
(c) 3x + 5 = \(\frac{2}{3}\)
(d) x³ – x = 5
Solution:
(c) 3x + 5 = \(\frac{2}{3}\)

Samacheer Kalvi 9th Maths Guide Chapter 3 Algebra Ex 3.15

Question 21.
Which of the following is a solution of the equation 2x – y = 6?
(a) (2, 4)
(b) (4, 2)
(c) (3, -1)
(d) (0, 6)
Solution:
(b) (4, 2)
Hint:
2x – y = 6
Substitute x – 4 and y = 2 we get
2(4) – 2 = 6 ⇒ 8 – 2 = 6 ⇒ 6 = 6
∴ (4, 2) is the solution

Question 22.
If (2, 3) is a solution of linear equation 2x + 3y = k then, the value of k is ……..
(a) 12
(b) 6
(c) 0
(d) 13
Solution:
(d) 13
Hint:
The equation is 2x + 3y = k
Substitute x = 2 and y = 3 we get,
2(2) + 3(3) = k ⇒ 4 + 9 = k ⇒ 13 = k

Question 23.
Which condition does not satisfy the linear equation ax + by + c = 0 ……..
(a) a ≠ 0, b = 0
(b) a = 0, b ≠ 0
(c) a = 0, b = 0, c ≠ 0
(d) a ≠ 0, b ≠ 0
Solution:
(c) a = 0, b = 0, c ≠ 0

Samacheer Kalvi 9th Maths Guide Chapter 3 Algebra Ex 3.15

Question 24.
Which of the following is not a linear equation in two variable?
(a) ax + by + c = 0
(b) 0x + 0y + c = 0
(c) 0x + by + c = 0
(d) ax + 0y + c = 0
Solution:
(b) 0x + 0y + c = 0
Hint:
0x + 0y + c = 0
0 + 0 + c = 0 ⇒ c = 0
There is no variable.
∴ It is not a linear equation

Question 25.
The value of k for which the pair of linear equations 4x + 6y – 1 = 0 and 2x + ky – 1 = 0 represents parallel lines is ……..
(a) k = 3
(b) k = 2
(c) k = 4
(d) k = -3
Solution:
(a) k = 3
Hint:
Slope of 4x + 6y – 1 = 0 is
6y = -4x + 1 ⇒ y = \(\frac{-4}{6}\) x + \(\frac{1}{6}\)
Slope = \(\frac{-4}{6}\) = \(\frac{-2}{3}\)
Slope of 2x + ky – 7 = 0
ky = -2x + 7
y = \(\frac{-2}{k}\)x + \(\frac{7}{k}\)
Slope of a line = \(\frac{-2}{k}\)
Since the lines are parallel
\(\frac{-2}{3}\) = \(\frac{-2}{k}\)
-2k = – 6
k = \(\frac{6}{2}\)
= 3

Samacheer Kalvi 9th Maths Guide Chapter 3 Algebra Ex 3.15

Question 26.
A pair of linear equations has no solution then the graphical representation is ……..
Samacheer Kalvi 9th Maths Guide Chapter 3 Algebra Ex 3.15 1
Solution:
Samacheer Kalvi 9th Maths Guide Chapter 3 Algebra Ex 3.15 2
Hint:
Since there is no solution the two lines are parallel. (l11m)

Question 27.
If \(\frac{a_1}{a_2}\) ≠ \(\frac{b_1}{b_2}\) where a1x + b1y + c1 = 0 and a2x + b2y + c2 = 0 then the given pair of linear equation has …….. solution(s).
(a) no solution
(b) two solutions
(c) unique
(d) infinite
Solution:
(c) unique
Hint:
Since it has unique solution
\(\frac{a_1}{a_2}\) ≠ \(\frac{b_1}{b_2}\)

Samacheer Kalvi 9th Maths Guide Chapter 3 Algebra Ex 3.15

Question 28.
\(\frac{a_1}{a_2}\) = \(\frac{b_1}{b_2}\) ≠ \(\frac{c_1}{c_2}\) where a1x + b1y + c1 = 0 and a2x + b2y + c2 = 0 then the given pair of linear equation has …….. solution(s).
(a) no solution
(b) two solutions
(c) infinite
(d) unique
Solution:
(a) no solution
Hint:
\(\frac{a_1}{a_2}\) = \(\frac{b_1}{b_2}\) ≠ \(\frac{c_1}{c_2}\) the linear equation has no solution.

Question 29.
GCD of any two prime numbers is …….
(a) -1
(b) 0
(c) 1
(d) 2
Solution:
(c) 1

Samacheer Kalvi 9th Maths Guide Chapter 3 Algebra Ex 3.15

Question 30.
The GCD of x4 – y4 and x² – y² is ……..
(a) x4 – y4
(b) x² – y²
(c) (x + y)²
(d) (x + y)4
Solution:
(b) x² – y²
Hint:
x4 – y4 = (x²)² – (y²)²
= (x² + y²)(x² – y²)
x² – y² = (x² – y²)
G.C.D. = x² – y²

Samacheer Kalvi 9th Social Science Guide Civics Chapter 4 Forms of Government

Tamilnadu State Board New Syllabus Samacheer Kalvi 9th Social Science Guide Pdf Civics Chapter 4 Forms of Government Text Book Back Questions and Answers, Important Questions, Notes.

Tamilnadu Samacheer Kalvi 9th Social Science Solutions Civics Chapter 4 Forms of Government

Samacheer Kalvi 9th Social Science Forms of Government Text Book Back Questions and Answers

I. Fill in the blanks

  1. _________, __________ are a few examples for unitary form of government.
  2. The parliamentary government is also known as __________
  3. In the parliamentary fonn of government __________is the leader of the majority party.

Answer:

  1. England, France
  2. Cabinet government
  3. Prime Minister

II. Fill in the blanks

Question 1.

S.No Country Name of the parliament
1. USA …………………………..
2. Norway …………………………..
3. …………………………… Folketing

Answer:

S.No Country Name of the parliament
1. USA Congress
2. Norway Storting
3. Denmark Folketing

III. Distinguish Between

The KTM full form is Kraftfahrzeuge Trunkenpolz Mattighofen, and KTM full form in English translation is ‘motor vehicle’.

Question 1.
Unitary and federal forms of government. Ans
Answer:
Unitary form of government:

  1. Only one level of government or sub units
  2. Subunits cannot operate independently
  3. E.g. England, France, Japan, Srilanka

Federal form of government:

  1. Two levels of government
  2. Federal units are answerable to central government
  3. E.g.U.S, Australia, Canada.

Samacheer Kalvi 9th Social Science Guide Civics Chapter 4 Forms of Government

Question 2.
Parliamentary and presidential forms of government.
Answer:
Parliamentary form of government:

  1. Prime Minister is the leader of the majority party.
  2. Central Legislature is supreme E.g.Canada, India, Japan

Presidential form of government:

  1. President is directly selected by the people.
  2. President is supreme E.g. Rassia, Brazil, U.S.A

IV. Give a short note on

Question 1.
Unitary form of government
Answer:
A unitary system of government or unitary state is a sovereign state governed as a single entity. The central government is supreme and the administrative divisions exercise only powers that the central government has delegated to them. England, France, Japan and Sri Lanka are examples of the Unitary Form of government. In a Unitary form of government, all the authority and power is vested in a single-center, whereas in a federal form of government authority and power is distributed between the center and the constituent units. Even in a Unitary form of Government, there might be a lot of decentralization of authority, but we cannot claim it as a federal system.

V. Answer the following

Question 1.
List out the types of constitution.
Answer:
Types of Constitution

Samacheer Kalvi 9th Social Science Guide Civics Chapter 4 Forms of Government

Question 2.
What are the merits of a federal government?
Answer:
The merits of the federal government are

  1. Reconciliation of local autonomy with national unity.
  2. Division power between centre and states leads to administrative efficiency.
  3. It gives rise to big states.
  4. Distribution powers check the despotism of central government.
  5. More suitable for bigger countries
  6. It is good for economic and cultural progress.

Samacheer Kalvi 9th Social Science Guide Civics Chapter 4 Forms of Government

Question 3.
Write down the differences between the unitary form of government and the federal form of government.
Answer:
Unitary form of government:

  1. Only one Level of Government or subunits
  2. Mostly Single Citizenship
  3. Sub Units cannot operate Independently
  4. No Division of Power
  5. Centralization of Power

The federal form of government:

  1. Two Levels of Government
  2. Dual Citizenship
  3. Federal Units are answerable to Central Government
  4. Division of Power
  5. Decentralization of Power

VI. Answer in detail

Question 1.
Write about the merits of a unitary form of government
Answer:
Merits of a unitary form of government

  • Suitable for small countries.
  • There is no conflict between authority and responsibility.
  • A unitary government will make prompt decisions and take speedy action.
  • A unitary government is less expensive.
  • Amendments to the constitution are easy.
  • There is unity, uniformity of law, policy, and administration.

Samacheer Kalvi 9th Social Science Guide Civics Chapter 4 Forms of Government

Question 2.
Write about the presidential form of government and what is the difference between presidential and parliamentary forms of government.
Answer:
Presidential form of government:

  1. The American President is both the head of the state and the head of government. As the head of state, he occupies a ceremonial position.
  2. The president is elected by an electoral college for a fixed tenure of four years.
  3. He governs with the help of a cabinet or a smaller body called ‘Kitchen Cabinet’. It is only an advisory body.
  4. The President and his secretaries are not responsible to Congress for their acts.
  5. The legislative, executive and judicial powers of the government are separated.
  6. It is also known as the non-responsible or non-parliamentary or fixed executive system of government.

Difference between Presidential and Parliamentary form of government Presidential Form of Government:

  1. President is directly elected by the people.
  2. President is supreme
  3. Separation of Powers
  4. Independent branches
  5. President-head of the Government
  6. Separation of Powers
  7. Independent branches
  8. Individual Leadership
  9. President is not accountable to Congress

Parliamentary form of Government:

  1. Prime Minister is the leader of the majority party.
  2. Central Legislature is supreme
  3. Absence of Separation Powers Centralisatiion
  4. Independent branches with Overlapping functions
  5. Prime Minister-head of the Government
  6. Centralisation
  7. Independent branches with Overlapping functions
  8. Collective leadership
  9. Collective and Individual Responsibility.

Samacheer Kalvi 9th Social Science Forms of Government Additional Important Questions and Answers

I. Fill in the blanks.

  1. The government in the main ______ of the state.
  2. There are ______ organs in a Government.
  3. Sri Lanka is an example of ______ form of government.
  4. Unitary form of government suitable ______ for Countres.
  5. U.S. represents form, ______ of government.
  6. The constitution is the ______ of the land.
  7. The Name of the Parliament in Israel in ______
  8. In India we have ______ form government.
  9. Brazil has ______ form of governments.
  10.  In Bhutan king Jigme is a ______ monarch.
  11. The Gross National Happiness (GNH) was first mentioned in the constitution of ______
  12. The term GNH was coined by ______

Answer:

  1. Agency
  2. Three
  3. unitary
  4. small
  5. Federal
  6. Supreme law
  7. Knesset
  8. Parliamentary
  9. Presidential
  10. Constitutional
  11. Bhutan
  12. Jigme Singye Wangchuck – King of Bhutan

Samacheer Kalvi 9th Social Science Guide Civics Chapter 4 Forms of Government

II. Fill in the blanks

Question 1.

S.No Country Name of the Parliment
1. Israel …………………………
2. Germany …………………………

Answer:

S.No Country Name of the Parliment
1. Israel …………………………
2. Germany …………………………

III. Distinguish Between

Question 1.
Dictatorship and Monarality
Dictatorship

  1. Dictatorship is an office that has been taken through force.
  2. A Dictatorship is termed as a government rule by one person or commands who is know as the Dictator. E.g. Uganda, Zimbawe

Monarchy

  1. Monarchy is resigned that passed from one generation to another.
  2. Monarchy is the rule of the king or green as an emperor. E.g. Britain, Australia.

Samacheer Kalvi 9th Social Science Guide Civics Chapter 4 Forms of Government

Question 2.
Democracy and Communism
Answer:
Democracy:

  1. Democracy is based on the principle of equality and Freedom.
  2. Private ownership is allowed citizens; have certain legislature and freedom which are protected by the constitution, E.g. India.

Communism:

  1. Communism is based on common ownership mainly concerned with equality and fairness.
  2. Here the government has complete control over the production and distribution of goods and all the resources shared equally in the society. E.g. China, North Korea.

IV. Give a short note on

Question 1.
Historic Transition in Bhutan.
Answer:

  1. The fourth king of Bhutan Jigme Singye Wangchuck travelled to all the 20 districts of the tiny kingdom.
  2. The purpose of the travel is to explain the importance of the historic transition to the people of Bhutan.
  3. The transition from the hereditary monarchy to the Parliamentary Democracy.
  4. In 2006 the king abdicated the throne 34 years after ascending it. Now Bhutan is a Parliamentary Democracy and King Jigme a constitutional monarch.

Samacheer Kalvi 9th Social Science Guide Civics Chapter 4 Forms of Government

Question 2.
What are the characteristics of good governance?
Answer:
Characteristics of Good governance

  1. Participation
  2. Rule of Law
  3. Transparency
  4. Responsiveness
  5. Consensus Orientation
  6. Equity
  7. Effectiveness And Efficiency
  8. Accountability

V. Answer the following

Question 1.
What are the demerits of federal form government?
Answer:
De-merits of the federal form of government are,

  1. Federal government is weaker when compared to the unitary government.
  2. Federal government is more expensive.
  3. Provincial tendencies are very common
  4. Lack of uniformity in Administration
  5. Threat to national unity
  6. Distribution powers between centre and states lead to conflict
  7. Double Citizenship
  8. Rigid constitution cannot be amended easily for the changing needs.
  9. The state governments sometimes place hindrances in foreign policy.

Samacheer Kalvi 9th Social Science Guide Civics Chapter 4 Forms of Government

Question 2.
Mention about the Unitary features of Indian constitution
Answer:
Unitary features of Indian constitution are

  1. Strong Centre
  2. Central Government’s control over state territory
  3. Single Constitution
  4. The flexibility of the Constitution
  5. Unequal representation of states
  6. Emergency Provisions
  7. Single citizenship
  8. Single Integrated Judiciary
  9. All India Services
  10. Appointment of Governor by the central government.

Question 3.
What are the Federal features of the Indian constitution?
Answer:
Federal features of the Indian constitution are

  1. Dual Government
  2. Written constitution
  3. Division of Powers
  4. The supremacy of the Constitution
  5. the constitution is the supreme law of the land.
  6. The laws enacted by the Centre and the states must conform to its provisions.
  7. Rigid Constitution
  8. Independent Judiciary
  9. Bicameralism

Samacheer Kalvi 9th Social Science Guide Civics Chapter 4 Forms of Government

Question 4.
Write about the demerits of a unitary form of government
Answer:
De-merits of a unitary form of government

  1. It is not suitable for big countries.
  2. The central government will have to tackle so many complex problems that lead to administrative delays.
  3. The central government will not concentrate on local problems, local interest and initiative.
  4. The concentration of powers .may pave way for the despotism of the central government.

VI. Answer in detail

Question 1.
Write note the Parliamentary form of Government
Answer:
Parliamentary form of Government:

  1. The parliamentary system of government is the one in which the executive is responsible to the legislature for its policies and acts.
  2. It is also known as cabinet government or responsible government or Westminister model of government and is prevalent in Britain, Japan, Canada, India among others.

Features of Parliamentary form of government:

  1. Nominal and Real Executives.
  2. Majority Party Rule
  3. Collective Responsibility
  4. Double Membership
  5. The leadership of the Prime Minister

Merits of the parliamentary form of government:

  1. Harmony between Legislature and Executive.
  2. Responsible Government
  3. Prevents Dictatorship.
  4. Wide Representation.

Demerits of the parliamentary form of government:

  1. Unstable Government.
  2. No Continuity of Policies.
  3. The dictatorship of the Cabinet.
  4. Against Separation of Powers.

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Tamilnadu State Board New Syllabus Samacheer Kalvi 9th Science Guide Pdf Chapter 1 Measurement Text Book Back Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 9th Science Solutions Chapter 1 Measurement

9th Science Guide Measurement Text Book Back Questions and Answers

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

I. Choose the correct answer :

Question 1.
Choose the correct one.
(a) mm < cm < m < km
(b) mm > cm > m > km
(c) km < m < cm < mm
d) mm > m > cm > km
Answer :
(a) mm < cm < m < km

Question 2.
Rulers, measuring tapes and metre scales are used to measure
(a) mass
(b) weight
(c) time
(d) length
Answer:
(d) length

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Question 3.
1 metric ton is equal to
(a) 100 quintals
(b) 10 quintals
(c) 1/10 quintals
(d) 1/100 quintals
Answer :
(b) 10 quintals

Question 4.
Which among the following is not a device to measure mass?
(a) Spring balance
(b) Beam balance
(c) Physical balance
(d) Digital balance
Answer :
(a) Spring balance

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

II. Fill in the blanks :

1. Metre is the unit of …………..
Answer :
length

2. 1 kg of rice is weighed by ……………
Answer :
beam balance

3. Thickness of a cricket ball is measured by ……………..
Answer :
vernier caliper

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

4. Radius of a thin wire is measured by …………………
Answer :
screw gauge

5. A physical balance measures small differences in mass up to ……………….
Answer :
1mg or less

III. State whether true or false. If false, correct the statement :

1. The SI unit of electric current is kilogram.
Answer:
False.
Correct statement: The SI unit of electric current is ampere.

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

2. Kilometre is one of the SI units of measurement.
Answer:
True.

3. In everyday life, we use the term weight instead of mass.
Answer:
True.

4. A physical balance is more sensitive than a beam balance.
Answer:
True.

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

5. One Celsius degree is an interval of IK and zero degree Celsius is 273.15 K.
Answer:
True.

6 . With the help of vernier caliper we can have an accuracy of 0.1 mm and with screw gauge we can have an accuracy of 0.01 mm.
Answer:
True.

IV. Match the following:

Question 1.

Column I Column II
Length kelvin
Mass metre
Time kilogram
Temperature second

Answer:

Column I Column II
Length metre
Mass kilogram
Time second
Temperature kelvin

Question 2.

Column I Column II
Screw gauge Vegetables
Vernier caliper Coins
Beam balance Gold ornaments
Digital balance Cricket ball

Answer:

Column I Column II
Screw gauge Coins
Vernier caliper Cricket ball
Beam balance Vegetables
Digital balance Gold ornaments

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

V. Assertion and reason type :

Mark the correct answer as :
(a) Both A and R are true but R is not the correct reason.
(b) Both A and R are true and R is the correct reason.
(c) A is true but R is false.
(d) A is false but R is true

Question 1.
Assertion (A) : The scientifically correct expression is “The mass of the bag is 10 kg”
Reason (R) : In everyday life, we use the term weight instead of mass.
Answer :
(a) Both A and R are true but R is not the correct reason

Question 2.
Assertion (A) : 0° C = 273.16 K. For our convenience we take it as 273K after rounding off the decimal.
Reason (R) : To convert a temperature on the Celsius scale we have to add 273 to the given temperature.
Answer :
(b) Both A and R are true and R is the correct reason

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Question 3.
Assertion (A) : Distance between two celestial bodies is measured in terms of light year.
Reason (R) : The distance travelled by the light in one year is one light year.
Answer:
(d) A is false but R is true
Distance between two celestial bodies is measured in terms of unit.

VI. Answer very briefly.

Question 1.
Define measurement.
Answer :
Measurement is the process of comparison of the given physical quantity with the known standard quantity of the same nature.

Question 2.
Define a standard unit.
Answer:
Unit is the quantity of a constant magnitude which is used to measure the magnitudes of other quantities of the same nature.

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Question 3.
What is the full form of SI system?
Answer:
The full form of S.I. system is the International System of Units.

Question 4.
Define least count of any device.
Answer:
Least count is the least measurement possible in a given device.
It is the distance moved by the tip of the screw for a rotation of one division on the head scale.
Least count = [Pitch / No. of head scale divisions]

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Question 5.
What do you know about pitch of screw gauge?
Answer:
Pitch of the screw gauge is the distance between two successive screw threads. It is measured by the ratio of distance travelled on the pitch scale to the number of rotations of the head scale.

Question 6.
Can you find the diameter of a thin wire of length 2 m using the ruler from your instrument box?
Answer:
No, I can not find the diameter of a thin wire of length 2 m using the ruler.

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

VII. Answer briefly :

Question 1.
Write the rules that are followed in writing the symbols of units in SI system.
Answer:

  •  The units named after scientists are not written with a capital initial letter.
    E.g. newton, henry, ampere, and watt.
  • The symbols of the units named after scientists should be written by the initial capital letter.
    E.g. N for newton, H for Henry, A for ampere, and W for watt.
  • Small letters are used as symbols for units not derived from a proper noun.
    E.g. m for metre, kg for kilogram.
  •  No lull stop or other punctuation marks should be used within or at the end of symbols.
    E.g. 50 m and not as 50 m.
  •  The symbols of the units are not expressed in plural form.
    E.g. 10 kg not as kgs.

Question 2.
Write the need of a standard unit.
Answer:
A Standard Unit is needed to maintain uniformity in measurements like length, weight, size and distance. Eg: Standard Unit of length is metre.

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Question 3.
Differentiate mass and weight.
Answer:
Mass:

  1.  Fundamental quantity
  2.  Has magnitude alone – scalar quantity
  3.  It is the amount of matter contained in a body
  4.  Remains the same
  5.  It is measured using physical balance
  6.  Its unit is kilogram

Weight:

  1.  Derived quantity
  2.  Has magnitude and direction – vector quantity
  3.  It is the normal force exerted by the surface on the object against gravitational pull
  4.  Varies from place to place
  5.  It is measured using spring balance
  6.  Its unit is newton

Question 4.
How will you measure the least count of vernier caliper?
Answer:
The least count of Vernier Caliper is the ratio of the value of one smallest main scale division to total
a number of Vernier scale divisions.
i.e., L.C. = 0.1mm = 0.01cm
(or) L.C. = 1MD – 1VSD = 1.0 mm – 0.9 mm = 0. 1mm = 0.01 cm

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

VIII. Answer in detail :

Question 1.
Explain a method to find the thickness of a hollow teacup.
Answer:
Step 1 : The Pitch, Least count and the type of zero error of the screw gauge are determined.
Step 2 : The given cup is placed in between two studs.
Step 3 : The head screw using the ratchet arrangement is freely rotated until the given cup is held firmly, but not tightly.
Step 4 : Pitch scale reading (PSR) by the head scale and head scale coincidence (HSC) with the axis of the pitch scale, are found.
Step 5 : The readings are recorded and the experiment for different positions of the given cup is repeated.
Step 6 : The thickness of the cup is calculated using the formula P.S.R + (HSC × L.C)
Step 7 : Then the average of the last column of the table, is found. Hence the thickness of a hollow tea cup = ………….. mm.

Question 2.
How will you find the thickness of a one rupee coin?
Answer:
Step 1 : The Pitch, Least count and the type of zero error of the screw gauge are determined.
Step 2 : The given coin is placed in between two studs.
Step 3 : The head screw using the ratchat arrangement is freely rotated until given one rupee coin is held firmly, but not tightly.
Step 4 : Pitch scale reading (PSR) by the head scale and head scale coincidence (HSC) with are axis of the pitch scale are found.
Step 5 : The reading are recorded and the experiment for different positions of the given coin is repeated.
Step 6 : The thickness of the coin is computed using the formula P.S.R + (HSC x L.C )
Step 7 : Then the average of the last column of the table is found.

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement 1
mean = …………….. mm
Hence the thickness of a one rupee coin = ……………….. mm

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

IX. Numerical Problems :

Question 1.
Inian and Ezhilan argue about the light year. Inian tells that it is 9.46 x 1015m and Ezhilan argues that it is 9.46 x 1012 km. Who is right? Justify your answer.
Answer:
(Inian is correct)
Light travels 3 × 108m in one second or 3 Lakhs kilometre in one second.
In one year we have 365 days.
The total number of second in one year is equal to 365 x 24 x 60 x 60
Distance travelled by light in 1 year = (3.153 x 107) x (3 x 108)
= 9.46 x 1015m

Question 2.
The main scale reading while measuring the thickness of a rubber ball using Vernier caliper is 7 cm and the Vernier scale coincidence is 6. Find the radius of the ball.
Answer:
MSR = 7 cm
VC = 6cm
LC = 0.1mm = 0.1cm
Diameter = DR = MSR + (VC X LC)
= 7 + 0.06 cm
Diameter D = 7.06 cm
Radius R = \(\frac{D}{2}=\frac{7.06}{2}\) = 0.035 m
The radius of the ball = 0.0353 m.

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Question 3.
Find the thickness of a five rupee coin with the screw gauge, if the pitch scale reading is 1 mm and its head scale coincidence is 68.
Answer:
PSR = 1 mm = 1 x 10-3m
HSC = 68
LC = 0.01 mm =0.01 × 10-3m
Total reading = PSR + (HSC × LC)
∴Thickness of the five rupee coin = 1 × 10-3 + (68 × 0.01 × 10-3 )m
∴ Thickness of the five rupee coin = 1.68 × 10-3m = 1.68mm

Question 4.
Find the mass of an object weighing 98 N.
Answer:
W = mg
W =98 N
g = 9.8 m/s2
m = \(\frac{\mathrm{W}}{\mathrm{g}}=\frac{98}{9.8}\) = 10 kg

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Intext Activities

ACTIVITY – 1

Using Vernier caliper find the outer diameter of your pen cap.
Samacheer Kalvi 9th Science Guide Chapter 1 Measurement 2
Aim : To find the outer diameter of the pen cap.
Materials required : Vernier caliper, pen cap.
Answer:
Samacheer Kalvi 9th Science Guide Chapter 1 Measurement 3
Result: The outer diameter of the pen cap = 9.35 cm
[End of the activity]

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Class 7 Science MCQ Questions with answers.

ACTIVITY – 2

Determine the thickness of a single sheet of your science textbook with the help of a Screw gauge.
Samacheer Kalvi 9th Science Guide Chapter 1 Measurement 4

LC = Least Count
PSR = Pitch Scale Reading
HSC = Head Scale Coincidence
HSR = Head Scale Reading
TR = Total Reading
Result : The thickness of the single sheet = 0.30
End of the activity

9th Science Guide Measurement Additional Important Questions and Answers

I. Choose the correct answer :

Question 1.
Length is ……………….
(a) The amount of matter in an object
(b) The amount of space an object takes up.
(c) The distance between two points.
(d) The amount of stuff in an object
Answer:
(c) The distance between two points

Question 2.
Mass is ………………….
(a) The distance between two points
(b) The distance between three points
(c) The amount of matter contained in an object
(d) The amount of space an object occupies.
Answer:
(c)The amount of matter contained in an object

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Question 3.
Unit used to measure length
(a) metre
(b) litre
(c) gram
(d) cubic metre (m3)
Answer:
(a) metre

Question 4.
Unit which is used to measure mass
(a) ml
(b) 1
(c) cm
(d) gram
Answer:
(d) gram

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Question 5.
How many metres are there in 1 nanometer?
(a) 10-10m
(b) 10-9m
(c) 109m
(d) 1010m
Answer:
(b) 10-9m

Question 6.
What unit will you use to measure the length of our classroom?
(a) km
(b) m
(c) cm
(d) mm
Answer :
(b) m

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Question 7.
The Kelvin is the basic unit of ………………..
(a) temperature
(b) mass
(c) length
(d) volume
Answer :
(a) temperature

Question 8.
……………….consists of ‘U’ shape metal frame
(a) Screw gauge
(b) Vernier caliper
(c) Beam balance
(d) Spring balance
Answer :
(a) screw gauge

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Question 9.
Least count of a vernier caliper is ……………. cm.
(a) 1
(b) 0.1
C) 0.01
(d) 0.001
Answer:
(c) 0.01

Question 10.
If no object is placed on the hook, then the pointer of the spring balance reads ………………….
(a) 3
(b) 2
(c) 1
(d) 0
Answer :
(d) 0

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Question 11.
SI unit of mass and weights are ………………….
(a) kg, N
(b) N, kg
(c) K, N
(d) N, K
Answer:
(a) kg, N

Question 12.
Units named after scientists …………………..
(a) lowercase
(b) upper case
(c) both (a) and (b)
(d) neither (a) or (b)
Answer:
(a) lower case

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Question 13.
An instrument that is used to measure the diameter of a cricket ball is ………………….
(a) Screw gauge
(b) Meter scale
(c) Vernier caliper .
(d) Spring balance
Answer:
(a) Vernier caliper

Question 14.
Distance between Chennai and Kanyakumari can be found in
(a) Kilometres
(b) Metres
(c) Centimetres
(d) Millimetres.
Answer:
(a) Kilometres

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

II. Fill in the blanks :

1. The precision of vernier calipers is ……………. mm.
Answer:
(a) 0.1mm

2. The gravity accelerates an object, the distance fallen is proportional to …………………
Answer:
time squared

3. SI unit of electric current is ………………
Answer:
ampere

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

4. Larger unit for measuring time is ………………..
Answer:
millennium

5. The value of an astronomical unit is ……………………
Answer:
1.496 x 1011

6. Mass is a …………….. quantity.
Answer:
scalar

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

III. State whether true or false. If false, correct the statement:

1. The precision of screw gauge is 0.001 cm.
Answer:
True.

2. The unit of amount of substance is candela
Answer:
False.
Correct statement: The unit of amount of substance is mole.

3. The symbol for the units derived from the names of scientists are written in capital letter
Answer:
True.

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

4. Yard was used as the unit of length.
Answer:
True

5. Micron is also known as micro-metre
Answer:
True

6. A vemier caliper using the scale invented by Galileo.
Answer:
False.
Correct statement: A vernier caliper using the scale invented by Pierre Vernier.

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

7. The SI unit of mass is kg.
Answer:
True.

8. Weight has both magnitude and direction.
Answer:
True.

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

IV. Match the following:

Question 1.

Column I Column II
FPS Metre, kilogram and second
CGS Foot, pound and second
MKS or SI centimetre, gram and second

Answer:

Column I Column II
FPS Foot, pound and second
CGS centimetre, gram and second
MKS or SI Metre, kilogram and second

Question 2.

Column-I Column-II
10 years 1 year
10 centuries 1century(100 years)
10 decades 1 millennium
365.24 days 1 decade

Answer:

Column-I Column-II
10 years 1 decade
10 centuries 1 millennium
10 decade 1century(100 years)
365.24 days 1 year

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Question 3.

Column-I Column-II
Electric Current radian
Luminous intensity ampere
Angle steradian
Solid angle candela

Answer:

Column-I Column-II
Electric Current ampere
Luminous intensity candela
Angle radian
Solid angle steradian

Question 4.

Column-I Column-II
Length s
Mass m
Time k
Temperature kg

Answer:

Column-I Column-II
Length m
Mass kg
Time s
Temperature k

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Question 5.

Column-I Column-II
Millimeter 10-15 m
Nanometer 10-3m
Angstrom 10-9m
Fermi 10-10m

Answer:

Column-I

Column-II
Millimeter 10-3m
Nanometer 10-9m
Angstrom 10-10m
Fermi 10-15 m

Question 6.

Column-I Column-II
Temperature Bearm balance
Mass Ruler
Length Digital clock
Time Thermometer

Answer:

Column-I Column-II
Temperature Thermometer
Mass Bearm balance
Length Ruler
Time Digital clock

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

V. Assertion and reason type :

Question 1.
Assertion (A) : Light year and wave length both measure distance
Reason (R) : Both have dimensions of time.
(a) Both A and R are true but R is not the correct explanation of A.
(b) Both A and R are true and R is the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
Answer :
(c) A is true but R is false

Question 2.
Assertion (A) : Density is a derived physical quantity
Reason (R) : Density cannot be derived from the fundamental physical quantities.
(a) Both A and R are true but R is not the correct explanation of A.
(b) Both A and R are true and,R-is the correct explanation of A.
(c) A is true but R is false. .
(d) A is false but R is true.
Answer :
(c) A is true but R is false
Correct statement: Density can be derived from mass and volume.

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Question 3.
Assertion (A) : Mass, Length and Time are fundamental physical quantities.
Reason (R) : They are independent of each other.
(a) Both A and R are true but R is not the correct explanation of A.
(b) Both A and R are true and R is the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
Answer :
b) Both A and R are true and R is the correct explanation of A

Question 4.
Assertion (A) : The SI system of units is the improved system of units for measurement.
Reason (R) : The SI unit of mass is kilogram.
(a) Both A and R are true but R is not the correct reason.
(b) Both A and R are true and R is the correct reason.
(c) A is true but R is false.
(d) A is false but R is true.
Answer :
(b) Both A and R are true and R is the correct reason

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Question 5.
Assertion (A) : The skill of estimation is important for all of us in our daily life.
Reason (R) : The skill of estimation reduces our consumption of time.
a) Both A and R are true but R is not the correct reason.
b) Both A and R are true and R is the correct reason.
c) A is true but R is false. ,
d) A is false but R is true.
Answer :
(b) Both A and R are true and R is the correct reason

VI. Comprehensive type :

(a) The speed of a body gives us an idea of how slow or fast that a body is moving. Speed of a body is the distance travelled by it per unit time. The SI unit of speed is metre per second. It is a scalar quantity. The speed of a running cab at any instant of time is shown by an instrument called, ’speedometer’ and the distance travelled by a car is measured by another instrument called, ‘odometer’.

Question 1.
Which the following is not a correct unit of speed?
(a) cm/s
(b) m/s
(e) km/h
(d) km/s.
Answer :
(d) km/s

Question 2.
If the distance travelled by the cab in 3 hours is 120 km, then its speed will be
(a) 40 m/s
(b) 40 km/s
(c) 40 km/h
(d) 40 km/min
Answer :
(c) 40 km/h

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Question 3.
The formula for finding the speed of the cab is
(a) Distance = speed x time
(b) velocity = distance x time
(c) time = distance x velocity
(d) None of these.
Answer:
(a) Distance = speed x time

(b) Read the passage and answer the questions given below.

Mass is the amount of matter contained in an object. Measurement of mass helps us to distinguish between lighter and a heavier body. Beam-Balance, spring balance and electronic balance are used to measure mass of different objects. The SI unit of mass is kilogram (kg). But different units are Used to measure the mass of different objects depending upon their weight, e.g. weight (mass) of a tablet is measured in milligrams (mg), weight of a student is measured in kilogram (kg), and weight of a truck with goods is measured in metric tons. 1 metric ton is equal to 10 quintals and 1 quintal is equal to 100 kg. 1 gram is equal to 1000 mg.

Question 1.
The value of 1 metric ton is equal to
(a) 1000 kg
(b) 10 quintals
(c) 1000,000 g
(d) 100 kg
Answer :
(a) 1000 kg (or) (b) 10 quintals

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Question 2.
How will you measure weight of a tablet?
(a) kg
(b) g
(c) mg
(d) none of these.
Answer:
(c) mg

VII. Answer very briefly :

Question 1.
Write the units which are used to measure long distances.
Answer:
km, AU, light-year, parsec.

Question 2.
Define Astronomical unit.
Answer:
AU is defined as the average distance between the earth and the sun.
1 AU = 1.496 × 1011m.

Question 3.
Define the light year.
Answer:
The distance travelled by light in one year in vacuum. 1 light-year = 9.46 × 1015m.

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Question 4.
Convert the temperature from Fahrenheit into Celsius & Kelvin.
Answer:
Samacheer Kalvi 9th Science Guide Chapter 1 Measurement 5

Question 5.
Convert 100°C into Kelvin.
Answer:
100 + 273 = 373 K. ie. °C + 273

Question 6.
Convert 112°F into K.
Answer:
Samacheer Kalvi 9th Science Guide Chapter 1 Measurement 6

Question 7.
Write the principle of screw gauge.
Answer:

  • When a screw is rotated in a nut, the distance moved by the tip of the screw is directly proportional to the number of rotations given.
  • Hence the principle of the screw is considered as the principle of screw gauge.

Question 8.
What are the kinds of units?
Answer:

  1. Fundamental or basic units
  2. Derived units

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Question 9.
Give some examples of fundamental units.
Answer:
The examples of fundamental units are kg for mass,m for length, s for time.

Question 10.
Give some examples of derived units.
Answer:
The units of area, volume, density.

Question 11.
What is the standard unit of weight?
Answer:
Newton is the standard unit of weight.

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Question 12.
What is the standard unit of mass?
Answer:
kilogram is the standard unit of mass.

Question 13.
Define Mass.
Answer:
Mass is the amount of matter contained in a body.

Question 14.
Define Weight.
Answer:
The force with which the earth attracts a body towards its center is called weight.

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Question 15.
What is the SI unit of temperature?
Answer:
Kelvin is the SI unit of temperature.

Question 16.
What is the measuring unit of the thickness of a plastic carry bag?
Answer:
1 micron = 10-6m (or) μm.

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

VIII. Answer briefly :

Question 1.
Write temperature conversion.
Answer:
Temperature Conversion (Exact)
Samacheer Kalvi 9th Science Guide Chapter 1 Measurement 7

Question 2.
Write about the positive zero error in screw gauge instrument.
Answer:
When the plane surface of the screw and the opposite plane stud on the frame are brought into contact, if the zero of the head scale lies below the pitch scale axis, the zero error is positive. For example, the 5th division of the head scale coincides with the pitch scale axis, then the zero error is positive and is given by Z.E = + (n × LC) where ‘n’ is the head scale coincidence. In this case, Zero error = + (5 × 0.01) = 0.05 mm. So the zero correction is – 0.05 mm
Samacheer Kalvi 9th Science Guide Chapter 1 Measurement 8

Question 3.
Write SI units for the fundamental quantity.
Answer:

Basic Quantity Unit
Length metre
Mass kilogram
Time second
Electric current ampere
Temperature kelvìn
Amount of substance mole
Luminous intensity candela

Question 4.
Convert the following units in metre.
Answer:

Smaller units Value in metre
Centimeter (cm) 10-2 m
Millimeter (mm) 10-3 m
micron or µm 10-6 m
nanometre (nm) 10-9 m
angstrom (A) 10-10 m
fermi (f) 10-15 m

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Question 5.
Draw and mark the parts of vernier caliper
Answer:
PARTS Marked in the Vernier caliper

  1. Lower fixed jaw
  2. Upper fixed jaw
  3. Lower movable jaw
  4. Vernier scale
  5. Retainer
  6. Main scale
  7. Depth probe.

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement 8

IX. Numerical Problems :

Question 1.
A piece of iron of volume 40cm3 whose density is 6.8g/cm3. Find the mass of iron.
Answer:
Given, density of iron, D = 6.8g/cm3
volume of iron, V = 40 cm3
mass of iron, M = V × D [∴ mass = volume × density]
Samacheer Kalvi 9th Science Guide Chapter 1 Measurement 10
m = 272.0g.

Question 2.
Solve : The mass of 40 apples in a box is 5 kg.
(i) Find the mass of a dozen of them.
(ii) Express the mass of one apple in gram.
Answer:
(i)  40 apple = 5 kg 5000 g
1 apple =\(\frac{500 \not 0}{4 \not \emptyset}\)
1 apple 125 g
∴ 1 dozen 12 apples
12 apples 125 × 12 g
12 apples 1500 g.

(ii)  40 apples = 5000 g

1 apple = \(\frac{5000}{40} \mathrm{~g}\)

1 apple = 125 g
The mass of 1 apple = 125 g

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

X. Answer in detail :

Question 1.
How will you find Zero Error of the screw gauge?
Answer:
Zero Error of a screw gauge :
When the plane surface of the screw and the opposite plane stud on the frame area brought into contact, if the zero of the head scale coincides with the pitch scale axis there is no zero error.

Positive zero error:
When the plane surface of the screw and the opposite plane stud on the frame are brought into contact, if the zero of the head scale lies below the pitch scale axis, the zero error is positive. For example, the 5th division of the head scale coincides with the pitch scale axis, then the zero error is positive and is given by
Z.E = + (n x LC) where ‘n’ is the head scale coincidence. In this case, Zero error = + (5 x 0.01) = 0.05mm. So the zero correction is -0.05 mm.
Samacheer Kalvi 9th Science Guide Chapter 1 Measurement 11

Negative zero error:
When the plane surface of the screw and the opposite plane stud on the frame are brought into contact, if the zero of the head scale lies above the pitch scale axis, the zero error is negative. For example, the 95th division coincides with the pitch scale axis, then the zero error is negative and is given by
ZE = -(100-n) × LC
ZE = – (100 – 95) × LC
= -(5 × 0.01)
= – 0.05 mm
The zero correction is + 0.05mm
Samacheer Kalvi 9th Science Guide Chapter 1 Measurement 12

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Question 2.
How will you find Zero Error of Vernier Caliper? Explain.
Answer:
Zero error:

  • Unscrew the slider and move it to the left, such that both the jaws touch each other. Check whether the zero marking of the main scale coincides with that of the Vernier scale.
  • If they are not coinciding with each other, the instrument is said to posses zero error. Zero error may be positive or negative.
  • If the zero mark of the Vernier is shifted to the right, it is called positive error.
  • On the other hand, if the Vernier zero is shifted to the left of the main scale zero marking, then the error is negative.

Positive zero error:

  • From the figure you can see that zero of the vernier scale is shifted to the right of zero of the main scale.
  • In this case the reading will be more than the actual reading.
  • Hence, this error should be corrected. In order to correct this error, find out which vernier division is coinciding with any of the main scale divisions.
  • Here, fifth vernier division is coinciding with a main scale division.
  • So, positive zero error = +5 × LC = +5 × 0.01 = 0.05 cm.
    Samacheer Kalvi 9th Science Guide Chapter 1 Measurement 13

Negative zero error:

  • You can see that zero of the vernier scale is shifted to the left of the zero of the main scale.
  • So, the obtained reading will be less than the actual reading.
  • To correct this error we should first find which vernier division is coinciding with any of the main scale divisions, as we found in the previous case.
  • In this case, you can see that sixth line is coinciding. But, to find the negative error, we can count backward (from 10).
  • So, the 4th line is coinciding. Therefore, negative zero error = -4 x LC = -4 x 0.01 = -0.04 cm.
    Samacheer Kalvi 9th Science Guide Chapter 1 Measurement 14

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Question 3.
Write short note on the following :
(i) Common balance
(ii) Physical balance Digital balance Spring balance
Answer:
Common (beam) balance :
A beam balance compares the sample mass with a standard reference mass (Standard reference masses are 5g, 10g, 20g, 50g, 100g, 200g, 500g, 1kg, 2kg, 5kg). This balance can measure mass accurately up to 5 g
Samacheer Kalvi 9th Science Guide Chapter 1 Measurement 15

Physical balance:
This balance is used in labs and is similar to the beam balance but it is a lot more sensitive and can measure mass of an object correct to a milligram.
The standard, reference masses used in this physical balance are 10 mg, 20 mg, 50 mg, 100 mg, 200 mg, 500 mg, 1 g, 2g, 5 g, 10 g, 20 g, 50 g, 100g, and 200 g.
Samacheer Kalvi 9th Science Guide Chapter 1 Measurement 16

Digital balance:
Nowadays, for accurate measurements digital balances are used, which measure mass accurately even up to a few milligrams, the least value being 10 mg (Figure 1.11). This electrical device is easy to handle and commonly used in jewellery shops and labs.
Samacheer Kalvi 9th Science Guide Chapter 1 Measurement 17

Spring balance:
This balance helps us to find the weight of an object. It consists of a spring fixed at one end and a hook attached to a rod at the other end. It works by ‘Hooke’s law’ which states that the addition of weight produces a proportional increase in the length of the spring. A pointer is attached to the rod which slides over a graduated scale on the right. The spring extends according to the weight attached to the hook and the pointer reads the weight of the object on the scale.
Samacheer Kalvi 9th Science Guide Chapter 1 Measurement 18

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

Tamilnadu State Board New Syllabus Samacheer Kalvi 9th Science Guide Pdf Chapter 2 Motion Text Book Back Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 9th Science Solutions Chapter 2 Motion

9th Science Guide Motion Text Book Back Questions and Answers

I. Choose the correct answer:

Online Average Acceleration calculator can be used to calculate Acceleration,​initial and final velocity and time taken.

Question 1.
The area under velocity – time graph represents the
(a) velocity of the moving object.
(b) displacement covered by the moving object,
(c) speed of the moving object.
(d) acceleration of the moving object.
Answer:
(b) displacement covered by the moving object

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

Question 2.
Which one of the following is most likely not a case of uniform circular motion?
(a) Motion of the Earth around the Sim.
(b) Motion of a toy train on a circular track.
(c) Motion of a racing car on a circular track.
(d) Motion of hours’ hand on the dial of the clock.
Answer:
(c) Motion of a racing car on a circular track

Question 3.
Which of the following graph represents uniform motion of a moving particle?
Samacheer Kalvi 9th Science Guide Chapter 2 Motion 1
Samacheer Kalvi 9th Science Guide Chapter 2 Motion 2
Answer:
Samacheer Kalvi 9th Science Guide Chapter 2 Motion 3

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

Question 4.
The centrifugal force is
(a) a real force.
(b) the force of reaction of centripetal force.
(c) a virtual force.
(d) directed towards the centre of the circular path.
Answer:
(c) a virtual force

II. Fill in the blanks :

1. Speed is a …………………….quantity whereas velocity is a …………….quantity.
Answer:
Scalar, Vector

2. The slope of the distance – time graph at any point gives ………………
Answer:
Speed

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

3. Negative acceleration is called ……………………
Answer:
retardation (or) deceleration

Displacement calculator is really a nice calculator that will help you solve a lot of your problems related to displacement.

4. Area under velocity – time graph shows ……………………………….
Answer:
displacement

III. State whether true or false. If false, correct the statement:

1. The motion of a city bus in a heavy traffic road is an example for uniform motion.
Answer:
False.
Correct statement: The motion of a city bus in a heavy traffic road is an example for non-uniform motion.

2. Acceleration can get negative value also.
Answer:
True.

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

3. Distance covered by a particle never becomes zero but displacement becomes zero.
Answer:
True.

4. The velocity – time graph of a particle falling freely under gravity would be a straight line parallel to the x axis. .
Answer:
False.
Correct statement: The velocity – time graph of aparticle moving at uniform do dry. would be straight line parallel to the x axis.

5. If the velocity – time graph of a particle is a straight line inclined to X-axis then its displacement – time graph will be a straight line.
Answer:
True.

IV. Assertion and Reason Type Questions :

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 are true but reason is not the correct explanation of assertion.
(c) If assertion is true but reason is false.
(d) If assertion is false but reason is true.

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

Question 1.
Assertion : The accelerated motion of an object may be due to change in magnitude of velocity or direction or both of them..
Reason : Acceleration can be produced only by change in magnitude of the velocity. It does not depend the direction.
Answer:
(c) If assertion is true but reason is false.

Use Average Velocity Calculator to find the average velocity, initial velocity, and final velocity with average velocity formula (vavg=(v+u)/2).

Question 2.
Assertion : The Speedometer of a car or a motor-cycle measures its average speed.
Reason : Average velocity is equal to total displacement divided by total time taken.
Answer:
(d) Assertion is false but reason is true

Question 3.
Assertion : Displacement of a body may be zero when distance travelled by it is not zero.
Reason : The displacement is the shortest distance between initial and final position.
Answer:
(a) Both assertion and reason are true and reason is the correct explanation of assertion

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

V. Match the Following :

Samacheer Kalvi 9th Science Guide Chapter 2 Motion 4
Answer:
Samacheer Kalvi 9th Science Guide Chapter 2 Motion 5

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

VI. Answer briefly :

Question 1.
Define velocity.
Answer:
Velocity is the rate of change of displacement. It. is the displacement in unit time.

Question 2.
Distinguish distance and displacement.
Answer:
Table
Distance

  1. The actual length of the path travelled by a moving body irrespective of the direction
  2. It is a Scalar quantity

Displacement:

  1. The change in position of a moving body in a particular direction
  2. It is a Vector quantity

Question 3.
What do you mean by uniform-motion?
Answer:
An object is said to be in uniform motion if it covers equal distances in equal intervals of time how so ever big or small these time intervals may be.

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

Question 4.
Compare speed and velocity.
Answer:

Speed Velocity
1. It is the rate of change of distance with respect to time It is the rate of change of displacement with respect to time
2. It is a scalar quantity having magnitude only It is a vector quantity having both magnitude and direction
3. Speed is velocity without a particular direction Velocity is speed in a particular direction
4. It is measured in ms-1 in SI system It is also measured in ms-1 in a particular direction in SI system
5. Speed in any direction would be a positive quantify, since the distance in any direction is a positive quantity. Velocity can get both positive and negative values. If velocity in one direction is assumed to be positive then the velocity in the opposite direction would be a negative quantity. Velocity can get zero value also.

Question 5.
What do you understand about negative acceleration?
Answer:
If v < u, i.e. if final velocity is less than initial velocity, the velocity decreases with time and the value of acceleration is negative. It is called negative acceleration. It is also called as retardation (or) deceleration.

Question 6.
Is the uniform circular motion accelerated? Give reasons for your answer.
Answer: When an object is moving with a constant speed along a circular path, the change in velocity is only due to the change in direction. Hence it is accelerated motion.

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

Question 7.
What is meant by uniform circular motion? Give two examples of uniform circular motion.
Answer:
When an object moves with constant speed along a circular path, the motion is called uniform circular motion.
Example :

  • The earth moves around the sun in the uniform circular motion.
  • The moon moves in uniform circular motion around the earth.

VII. Answer in detail :

Question 1.
Derive the equations of motion by graphical method.
Answer:
Equations of motion from velocity-time graph:
Samacheer Kalvi 9th Science Guide Chapter 2 Motion 6

Graph shows the change in velocity with time of a uniformly accelerated object. The object starts from the point D in the graph with velocity u. Its velocity keeps increasing and after time t it reaches the point B on the graph.
The initial velocity of the object = u = OD = EA
The final velocity of the object = v = OC = EB
Time = t = OE = DA
Also from the graph we know that, AB = DC

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

1. First equation of motion :

By definition, acceleration = change in velocity / time
= (final velocity – initial velocity)/time
= (OC – OD) / OE
= DC / OE
a = DC /t
DC = AB = at
From the graph EB = EA + AB
v = u + at…………..(1)
This is first equation of motion. .

2. Second equation on of motion :
From the graph the distance covered by the object during time t is given by the area of quadrangle DOEB

s = area of the quadrangle DOEB
= area of the rectangle DOEA + area of the triangle DAB
= (AE x OE) + (1/2 × AB × DA) .
s = ut + 1/2 (at2) …………(2)
This is the second equation of motion.

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

3. Third equation of motion :
From the graph the distance covered by the object during time, t is given by the area of the quadrangle DOEB. Here DOEB is a trapezium. Then,
s = area of trapezium DOEB
= 1/2 × sum of length of parallel side × distance between parallel sides
= 1/2 × (OD + BE) × OE
S = 1/2 ×× (u + v) × t
since a = (v – u) /1 or t = (v – u) / a
Therefore s = 1/2 × (v + u) x (v – u) / a
2as = v2 – u2
v2 = u2 + 2 as …………….. (3)
This is the third equation of motion.

Question 2.
Explain different types of motion.
Answer:
In physics, motion can be classified as below.

1. Linear motion: Motion along a straight line.

2. Circular motion: Motion along a circular path.

3. Oscillatory motion: Repetitive to and fro motion of an object at regular intervals of time. Random motion: Motion of the object which does not fall in any of the above categories.

Uniform and Non-uniform motion:

Uniform motion: Consider a car that covers 60 km in the first hour, 60 km in the second horn-, and another 60 km in the third hour, and so on. The car covers equal distance at equal intervals of time. We can say that the motion of the car is uniform. An object is said to be in uniform motion if it covers equal distances in equal intervals of time howsoever big or small these time intervals may be.

Non-uniform motion: Now, consider a bus starting from one stop. It proceeds slowly when it passes through a crowded area of the road. Suppose, it manages to travel merely 100 m in 5 minutes due to heavy traffic and is able to travel about 2 km in 5 minutes when the road is clear. Hence, the motion of the bus is non-uniform i.e. it travels unequal distances in equal intervals of time.

VIII. Exercise Problems:

Question 1.
A ball is gently dropped from a height of 20 m. If its velocity increases uniformly at the rate of 10ms-2, with what velocity will it strike the ground? After what time will it strike the ground?
Answer:
Here we have
Initial velocity, u = 0
Distance, s = 20 m
Acceleration, a = 10 m/s2
Final velocity, v = ?
Time, t = ?

a) Calculation of final velocity, v
We know that, v2 = u2 + 2as
v2 = 0 + 2 × 10m/s2 × 20m
v2 = 400m2/s2
\(=\sqrt{400 m^{2} / s^{2}}\)
v = 20m/s

b) Calculation of time, t
We know that, v = u + at
20 m/s = 0 + 10m/s2 × t
t = \(\frac{20 m / s^{2}}{20 m / s}=2 s\)
∴ Ball will strike the ground at a velocity of 20 ms-1
Time taken to reach the ground = 2s.

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

Question 2.
An athlete completes one round of a circular track of diameter 200 m in 40 s. What will be the distance covered and the displacement at the end of 2 m and 20 s?
Answer:
Here we have
Diameter = 200. m
∴ Radius = 200 m/2 = 100 m
Time of one rotation = 40 s
Time after 2m 20 s = 2 × 60 s +20 s = 140 s
Distance after 140 s = ?
Displacement after 140 s = ?
Circular track with a diameter of 200m
We know that, velocity
Samacheer Kalvi 9th Science Guide Chapter 2 Motion 7
Samacheer Kalvi 9th Science Guide Chapter 2 Motion 8

a) Distance after 140 s
We know that, distance = velocity × time
= Distance 15.7 rn/s × 140 s
= 2198m

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

b) Displacement after 2 min 20 s i.e, in 140 s
We know that, distance = velocity × time
Since, rotation in 40 s = 1
∴ Rotation in 1 s = \(\frac{1}{40}\)
∴ Rotation in 140 s = \(\frac{1}{40} \times 140=3.5\)
∴ In 3.5 rotation athlete will be just at the opposite side of the circular track,
i.e. at a distance equal to the diameter of the circular track which is equal to 200m
∴ Distance covered in 2min 20 s = 2198 m
Displacement after 2min 20 5 = 200 m.

Question 3.
A racing car has a uniform acceleration of 4ms-2. What distance it covers in 10s after the start?
Answer:
Here we have
Acceleration, a = 4 m/s2.
Initial velocity u = 0
Time t = 10 s
Distance (s) covered =?
We know that, s = ut + \(\frac { 1 }{ 2 }\) at2
s = (0 × 10s) + [\(\frac { 1 }{ 2 }\) × 4 m/s2 × (10 s)2]
= \(\frac { 1 }{ 2 }\) × 4 m/s2 × 100 s2
= 2 × 100 m = 200 m

Thus, racing car will cover a distance of 200 m after start in 10s with given acceleration.

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

Intex Activities

ACTIVITY – 1

Look around you. You can see many things: a row of houses, large trees, small plants, flying birds, running cars and many more. List the objects which remain fixed at their position and the objects which keep on changing their position.
Solution:

  1. Row of houses, large trees, small plants are the examples, of immovable objects.
  2. Flying birds, running cars and buses are the examples of movable objects.

Activity to be done by the students themselves

ACTIVITY – 2

Tabulate the distance covered by a bus in a heavy traffic road in equal intervals of time and do the same for a train which is not in an accelerated motion. From your table what do you understand?
The bus covers unequal distance in equal intervals of time but the train covers equal distances in equal intervals of time.
Solution:
Samacheer Kalvi 9th Science Guide Chapter 2 Motion 9

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

ACTIVITY – 3

Observe the motion of a car as shown in the figure and answer the following questions:
Compare the distance covered by the car through the path ABC and AC. What do you observe? Which path gives the shortest distance to reach D from A? Is it the path ABCD or the path ACD or the path AD?
Samacheer Kalvi 9th Science Guide Chapter 2 Motion 10
Solution:

  1. Distance covered by the car through the path ABC = 4m + 3m = 7 m. and AC = 5 m. The distance covered by the car through the path ABC is large compared to AC.
  2. The shortest distance to resell D from A is path AD = 3m.
  3. The total distance covered by the car ABCD A = 14 m. It finally reaches to A.

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

ACTIVITY – 4

Take a large stone and a small eraser. Stand on the top fit a table and drop them simultaneously from the same height? What do you observe? Now, take a small eraser and a sheet of paper. Drop them simultaneously from the same height. What do you observe? This time, take two sheets of paper having same mass and crumple one of the sheets into a ball. Now, drop the sheet and the ball from the same height. What do you observe?
Solution :
Both the stone and the eraser have reached the surface of the earth almost at the same time.
The eraser reaches first and the sheet of paper reaches later.
The paper crumpled into a ball reaches ground first and plain sheet of paper reaches later, although they have equal mass. It is because of air resistance. The magnitude of air resistance despends on the area of object exposed to air. So the sheet of paper reaches later.

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

9th Science Guide Motion Additional Important Questions and Answers

I. Choose the correct answer :

Question 1.
A particle is moving in a circular pattern of radius r. The displacement after half a circle would be
(a) zero
(b) πr
(c) 2r
(d) 2πr
Answer:
(c) 2r

Question 2.
In which of the following cases of motions, the distance moved and the magnitude of displacement are equal?
(a) If the car is moving in the straight road.
(b) If the car is moving in a circular road.
(c) The earth is revolving around the sun.
(d) The pendulum is moving to and fro
Answer:
(a) If the car is moving in the straight road

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

Question 3.
A body is thrown vertically upward with velocity, the greatest height h to which it will rise is
(a) u2/2g
(b) u2/g
(c) u/g
(d) u/2g
Answer:
(a) u2/2g

Question 4.
If the displacement of an object is proportional to square of time, then the object moves with
(a) uniform velocity
(b) uniform acceleration
(c) increasing acceleration
(d) decreasing acceleration
Answer:
(b) uniform acceleration

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

Question 5.
From the given v-t graph, u can be inferred that the object is
(a) in uniform motion
(b) at rest
(c) in non-uniform motion
(d) moving with uniform acceleration
Answer:
(a) in uniform motion

Question 6.
The area under v-t graph represents a physical quantity which has the unit.
(a) m2
(b) m
(c) m3
(d) ms-1
Answer:
(b) m

Question 7.
m/s2 is the unit of
(a) distance
(b) displacement
(c) velocity
(d) acceleration
Answer:
(d) acceleration

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

Question 8.
The rate of change of displacement
(a) speed
(b) velocity
(c) acceleration
(d) retardation
Answer:
(b) velocity

Question 9.
A scalar quantity has T
(a) magnitude only
(b) direction only
(c) both
(d) none
Answer:
(a) magnitude only

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

Question 10.
When an object undergoes acceleration
(a) there is always an increase in its velocity
(b) there is always an increase in its speed
(c) a force always acting on it.
(d) all of the above
Answer:
(c) a force always acting on it

Question 11.
A body is projected up with an initial velocity u m/s. It goes up to a height, ‘h’ metres in seconds time. Then it comes back at the point of projection. Considering negligible air resistance, which of the following statement is true?
(a) the acceleration is zero
(b) the displacement is zero
(c) the average velocity is 2hit
(d) the final velocity is 2u when body reaches projection point
Answer:
(b) the displacement is zero

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

Question 12.
A car accelerates at 1.5m/s2in a straight road. How much is the increase in velocity in 4s.
(a) 6 m/s
(b) 4 m/s
(c) 3 m/s
(d) 2.66 m/s
Answer:
(a) 6 m/s

Question 13.
The slope of the distance-time curve is steeper / greater is the
(a) velocity
(b) acceleration
(c) displacement
(d) speed
Answer:
(d) speed

Question 14.
The given graph represents motion with …………….speed.
Samacheer Kalvi 9th Science Guide Chapter 2 Motion 11
(a) uniform
(b) non-uniform
(c) constant
(d) none
Answer:
(b) non-uniform

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

Question 15.
The relation between displacemeñt and time is given by the equation of
(a) v2 = ut + at
(b) s = ut + \(\frac { 1 }{ 2 }\) at2
(e) c = s/t
(d) v2 = u2 + 2as
Answer:
(b) s = ut + \(\frac { 1 }{ 2 }\) at2

Question 16.
A body moves in a uniform circular motion
(a) It is moving with constant velocity
(b) its acceleration is zero
(c) the body has an acceleration y
(d) none of the above
Answer:
(a) It is moving with constant velocity

Question 17.
Speed of the body in particular direction can be called
(a) acceleration
(b) displacement
(c) velocity
(d) distance
Answer:
(c) velocity

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

Question 18.
Statement A: Uniform circular motion is a case of accelerated motion
Statement B: In third equation of motion we do not have the term time
(a) Statement B is true, A is false
(b) Statement A is true, B is false
(c) neither statement A nor B is true
(d) both are true
Answer:
(d) both are true

Question 19.
Which of the following is correct about uniform circular motion
(i) direction of motion is continuously changed
(ii) direction of motion is not changed
(iii) speed and direction both remain constant
(iv) speed is constant but direction is changing
(a) ii & iii are correct
(b) i, ii & iii are correct
(c) i & iv are correct
(d) all of these
Answer:
(c) i & iv are correct

Question 20.
Which of the quantities have the same SI unit?
(a) speed, velocity
(b) acceleration, time
(c) velocity, time
(d) velocity, acceleration
Answer:
(a) speed, velocity

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

Question 21.
Rest and motion of body are
(a) non-relative
(b) not related
(c) relative
(d) none
Answer:
(c) relative

Question 22.
An ant moves from one corner of a room diagonally to the opposite corner. If the dimensions of the hall are 8m x 6m, the displacement of the ant is
(a) 10m
(b) 14m
(c) 28m
(d) 2m
Answer:
(a) 10m

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

Question 23.
The displacement covered by a second hand of radius V in a clock after one revolution is
(a) 360°
(b) 0
(c) 3r
(d) 2r
Answer:
(b) 0

Question 24.
A man leaves his house at 6.30 a.m. for a morning walk and returns back at 7.30 a.m. after covering 4 km. Displacement covered by him is …………….
(a) 2 km
(b) zero
(c) 8 km
(d) 4 km
Answer:
(b) zero

Question 25.
A body is said to be in non uniform motion if it travels
(a) equal distance in unequal interval of time
(b) equal distance in equal interval of time
(c) unequal distance in unequal interval of time
(d) unequal distance in equal interval of time.
Answer:
(d) unequal distance in equal interval of time

Question 26.
A quantity which has both magnitude and direction is
(a) scalar
(b) distant
(c) vector
(d) moving body
Answer:
(c) vector

Question 27.
A bus accelerating with 4ms-2 changes its speed from 60ms_1 to a certain value in 5s. The final speed is
(a) 40 m/s
(b) 25 ms-1
(c) 60 ms-1
(d) 30 ms-1
Answer:
(a) 40 m/s

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

Question 28.
A quantity has a value of 16ms-2. It is the
(a) acceleration of an object
(b) velocity of an object
(c) retardation of an object
(d) speed of an object
Answer:
(c) retardation of an object

Question 29.
A boy throws a ball up and catches it when the ball falls back. In which part of the motion the ball is accelerating?
(a) during downward motion
(b) when the ball comes to rest
(c) during upward motion
(d) when the boy catches the ball.
Answer:
(a) during downward motion]

Question 30.
Choose the correct option.
(a) distance is a scalar, velocity is a vector, acceleration is a vector
(b) distance is a vector, velocity is a scalar, acceleration is a vector
(c) distance is a vector, velocity is a vector, acceleration is a vector
(d) distance is a scalar, velocity is a vector, acceleration is scalar
Answer:
(a) distance is a scalar, velocity is a vector, acceleration is a vector

Question 31.
If a moving body comes to rest, then its acceleration is
(a) positive
(b) negative
(c) zero
(d) all of these depending upon initial velocity.
Answer:
(b) negative

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

Question 32.
If the velocity of a body changes uniformly from u to v in time t, the sum of average velocity and acceleration is
Samacheer Kalvi 9th Science Guide Chapter 2 Motion 12
Samacheer Kalvi 9th Science Guide Chapter 2 Motion 13
Answer:
Samacheer Kalvi 9th Science Guide Chapter 2 Motion 14

Question 33.
Acceleration is defined as the rate of change of
(a) distance
(b) velocity
(c) speed
(d) displacement
Answer:
(b) velocity

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

Question 34.
When an object undergoes acceleration
(a) there is always an increase in its velocity ‘
(b) there is always an increase in its speed
(c) a force always acting on it.
(d) all the above
Answer:
(c) a force always acting on it

Question 35.
The equation v = u + at gives information as
(a) velocity is a function of time
(b) velocity is a function of position
(c) position is a function of time
(d) position is a function of time and velocity
Answer:
(a) velocity is a function of time

Question 36.
Which of the following can determine the acceleration of a moving object.
(a) area of the velocity-time graph
(b) the slope of the velocity-time graph
(c) area of a distance-time graph
(d) the slope of a distance-time graph
Answer:
(b) slope of the velocity-time graph

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

Question 37.
What is the slope of the body when it moves with uniform velocity?
(a) positive
(b) negative
(c) zero
(d) may be positive or negative
Answer:
(c) zero]

Question 38.
If a body starts from rest, what can be said about the acceleration of the body?
(a) positively accelerated
(b) negative accelerated
(c) uniform accelerated
(d) none of the above
Answer:
(a) positively accelerated

Question 39.
When a body moves uniformly along the circle then
(a) its velocity changes but speed remain the same
(b) its speed changes but velocity remains the same
(c) both speed and velocity changes
(d) both speed and velocity remains same
Answer:
(a) its velocity changes but speed remains the same

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

Question 40.
Distance travelled by a freely falling body is proportional to
(a) mass of the body
(b) square of the acceleration due to gravity
(c) square of the time of fall
(d) time of fall
Answer:
(c) square of the time of fall

Question 41.
If the displacement-time graph of a particle is parallel to the time axis, then velocity of the particle is.
(a) infinity
(b) unity
(c) equal to acceleration
(d) zero
Answer:
(d) zero

Question 42.
In the velocity-time graph, AB shows that the body has
Samacheer Kalvi 9th Science Guide Chapter 2 Motion 15
(a) uniform acceleration
(b) non-uniform retardation
(c) uniform speed
(d) initial velocity OA & is moving with uniform retardation.
Answer:
(d) initial velocity OA & is moving with uniform retardation

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

Question 43.
The magnitude of the centripetal force is given by (F= ….)
Samacheer Kalvi 9th Science Guide Chapter 2 Motion 16
Samacheer Kalvi 9th Science Guide Chapter 2 Motion 17
Answer:
Samacheer Kalvi 9th Science Guide Chapter 2 Motion 18

Question 44.
A body moving with an initial velocity 5ms-1 and accelerates at 2ms -2. Its velocity after 10s is
(a) 20ms-1
(b) 25ms-1
(c) 5ms-1
(d) 22.55ms-1
Answer:
(b) 25ms-1

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

Question 45.
In a 100m race, the winner takes 10s to reach the finishing point. The average speed of the winner is
(a) 5ms-1
b) 20ms-1
c) 40ms-1
d) 10ms-1
Answer:
(d) 10ms-2

Question 46.
The area under the velocity-time graph represents
(a) the velocity of the moving object
(b) displacement covered by the moving object
(c) speed of the moving object.
(d) acceleration of the moving object
Answer:
(b) displacement covered by the moving object

Question 47.
A car is being driven at a speed of 20ms-1 when brakes are applied to bring it to rest in 5 s. The deceleration produced in this case will be
(a) +4ms-2
(b) -4ms-2
(c) -0.25ms-2
(d) +0.25ms-2
Answer:
(b) -4ms-2

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

Question 48.
Unit of acceleration is
(a) ms-1
(b) ms-2
(c) ms
(d) ms2
Answer:
(b) ms-2

Question 49.
The force responsible for drying clothes in a washing machine is …………….
(a) Centripetal force
(b) Centrifugal force
(c) Gravitational force
(d) Electro static force
Answer:
(b) Centrifugal force

II. Fill in the blanks:

1. If a body does not change its position, then it is said to be at …………………
Answer:
rest

2. The back and forth motion of a swing is an ………………… motion.
Answer:
Oscillatory

3. In uniform motion an object travels equal ………………… in ………………… interval of time.
Answer:
distances, equal

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

4. The actual path covered by a body is called …………………
Answer:
distance

5. Displacement is the ………………… distance covered by a body.
Answer:
shortest

6. The motion of the bus is ………………… motion.
Answer:
non-uniform

7. Rate of change of displacement is …………………
Answer:
velocity

8. Speed is a ………………… quantity whereas velocity is a …………………
Answer:
scalar, vector

9. If final velocity is less than initial velocity the acceleration is ………………….
Answer:
negative

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

10. If final velocity is equal to initial velocity the value of acceleration is ………………….
Answer:
zero

11. The slope of the distance-time graph becomes steeper & steeper the speed ………………….
Answer:
increases

12. A straight line parallel to the x-axis in the velocity-time graph, represents the object moves in…………………
Answer:
uniform velocity

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

13. From v-t graph ………………… can be calculated.
Answer:
displacement

14. ………………… measures the instantaneous speed of the automobile.
Answer:
Speedometer

15. Slope of the velocity-time graph gives…………………
Answer:
acceleration

16. The value of acceleration for a body at rest is…………………
Answer:
zero

17. At the highest point, when a body is thrown vertically upwards, the velocity is ………………….
Answer:
zero

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

18. A body moves in a circular pattern the ………………… of velocity does not change but changes.
Answer:
magnitude, direction

19. When a body moves in a circular pattern ………………… acceleration is directed radially towards the centre of the circle.
Answer:
centripetal

20. The separation of cream from milk-hn example for the application of ………………….
Answer:
centrifugal

21. Consider an object is rest at position x = 20m. Then its displacement – time graph will be straight-line ………………… to the time axis.
Answer:
Parallel

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

III. State whether true or false. If false, correct the statement:

1. Displacement can be zero but distance never.
Answer:
True.

2. Time is a vector quantity.
Answer:
False.
Correct statement: Time is a scalar quantity.

3. Displacement magnitude can be greater than the distance travelled by the object.
Answer:
True.

4. If the velocity of the body decreases with time the acceleration is negative and the motion is called decelerated motion.
Answer:
True.

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

5. Acceleration is a scalar.
Answer:
False.
Correct statement: Acceleration is a vector.

6. The area of the velocity-time graph gives the displacement of the body.
Answer:
True.

7. Motion & rest are relative terms.
Answer:
True.

8. An object can be moving with uniform speed but variable acceleration.
Answer:
True.

9. Slope of the distance-time graph indicates the speed.
Answer:
True.

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

10. It is possible to have object moving with uniform velocity but non-uniform acceleration.
Answer:
True.

11. It is possible to have object moving with uniform speed but variable acceleration.
Answer:
False.
Correct statement : It is possible to have object moving with uniform speed but constant acceleration.

12. The force experienced by a boy in the merry-go-round is a centripetal force.
Answer:
False.
Correct statement: The force experienced by a boy in the merry-go-round is a centrifugal force.

13. The initial velocity of a freely falling object is zero as it is released from rest.
Answer:
True.

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

IV. Assertion and Reason Type Questions :

(a) If both assertion & reason are true and the reason is the correct explanation of the assertion.
(b) If both assertion & reason are true but the reason is not correct explanation of the assertion.
(c) If the assertion is true but the reason is false.
(d) If assertion & reason both are false.
(e) If assertion is false but reason is true.

Question 1.
Assertion : A body can have acceleration even if its velocity is zero at a given instant of time.
Reason: A body is momentarily at rest when it reverses its direction of motion.
Answer:
(a) Both assertion & reason are true and the reason is the correct explanation of the assertion

Question 2.
Assertion : If the displacement of the body is zero, the distance covered by it may not be zero.
Reason: Displacement is a vector & distance is a scalar quantity.
Answer:
(a) Both assertion & reason are true and the reason is the correct explanation of the assertion

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

Question 3.
Assertion: An object can have constant speed but the variable velocity
Reason: Speed is a scalar but velocity is a vector.
Answer:
(a) Both assertion & reason are true and the reason is the correct explanation of the assertion

Question 4.
Assertion: The speed of a body can be Negative.
Reason : If the body is moving in the opposite direction of positive motion, then its speed is Negative.
Answer:
(d) Assertion & reason both are false

Question 5.
Assertion : The position-time graph of a uniform motion in one dimension of a body can have Negative slope
Reason : When the speed of body decreases with time then, position-time graph of the moving body has Negative slope.
[Answer:
(c) Assertion is true but the reason is false

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

Question 6.
Assertion: A positive acceleration of a body can be associated with slowing down of the body.
Reason: Acceleration is a vector.
[Answer: (b) Both assertion & reason are true but the reason is not correct explanation of the assertion]

Question 7.
Assertion :A negative acceleration of a body can be associated with speeding up of the body.
Reason: Increase in speed of a moving body is independent of its direction of motion.
Answer:
(b) Both assertion & reason are true but the reason is not the correct explanation of the assertion

Question 8.
Assertion When a body is subjected to a uniform acceleration, it is always moving in a straight line.
Reason: Motion may be straight-line motion or circular motion.
Answer:
(e) Assertion is false but the reason is true

Question 9.
Assertion : Position-time graph of a stationary object is a straight line parallel to time axis. ’
Reason : For a stationary object, position does not change with time.
Answer:
(a) Both assertion & reason are true and the reason is the correct explanation of the assertion

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

Question 10.
Assertion : The slope of distance-time graph of a body moving with high speed is steeper than slope of distance-time graph of a body with low velocity.
Reason: Slope of distance-time graph = speed of the body.
Answer:
(a) Both assertion & reason are true and the reason is the correct explanation of the assertion

V. Answer briefly :

Question 1.
What are centripetal acceleration and centripetal force?
Answer:
When a body moves in a circular pattern the acceleration is directed radially towards the centre of the circle.
The force causing this acceleration is also directed towards the centre of the circle and it is called centripetal force.

Question 2.
Find the magnitude of centripetal force.
Answer:
Consider an object of mass m, moving along a circular path of radius r, with a velocity v, its centripetal acceleration is given by a = v2 / r
Hence, the magnitude of centripetal force is given by,
F = mass x centripetal acceleration
F = mv2 / r

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

Question 3.
What is centrifugal force? Give examples.
Answer:
Force acting on a body away from the centre of circular path is called centrifugal force. Thus centrifugal force is in a direction opposite to the direction of centripetal force. Its magnitude is same as that of centripetal force.
Example : Spin dryer of a washing machine, ride on a merry-go-round.

Question 4.
When an object is thrown upwards, what is true of velocity and acceleration at the highest point of motion of the object?
Answer:

  • Velocity becomes zero
  • Acceleration remains same as g.

Question 5.
Name the two quantities, the slope of whose graph gives (i) speed (ii) acceleration.
Answer:
(i) Distance – Time
(ii) Speed – Time

Question 6.
Define Average speed.
Answer:
It is the total distance travelled divided by the total time taken to cover this distance.
Samacheer Kalvi 9th Science Guide Chapter 2 Motion 19

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

Question 7.
What do you infer if
(i) Distance – time graph is straight line.
(ii) Velocity time graph is curved.
(iii) Displacement time is zig zag.
Answer:
(i) Speed is constant.
(ii) Acceleration is not uniform.
(iii) Non uniform velocity.

Question 8.
Give the formula for each.
(i) Relation between initial, final velocity, acceleration and displacement in a uniformly accelerated straight line motion.
(ii) Relation between initial, final velocity, acceleration & time in a uniformly accelerated straight line motion.
(iii) Relation between initial velocity, acceleration, displacement and time.
Answer:
(i) Relation between initial, final Velocity, acceleration & displacement
in a uniformly accelerated straight line motion. v2 = u2 + 2as
(ii) Relation between initial, final velocity, acceleration & time
in a uniformly accelerated straight line motion. v = u + at
(iii) Relation between initial velocity, acceleration, displacement and time. s = ut+ 1/2 at2

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

Question 9.
What is the difference between uniform acceleration and non – uniform acceleration?
Answer:
Uniform Acceleration

  1. It is the acceleration in which the object changes its velocity with equal intervals of time.
  2. eg. The motion of a ball rolling down.

Non – Uniform Acceleration

  1. It is the acceleration in which the object changes its velocity with unequal intervals of time.
  2. A car travels 2 km in 1st hour, 3 km in 2nd hour and 3.5 km in 3rd horn.

Question 11.
Define Acceleration.
Answer:
Acceleration is the rate of change of velocity with respect to time or it is the rate of change of velocity in unit time. It is a vector quantity. The SI unit of acceleration is

VI. Paragraph Questions :

Question 1.
Define acceleration and state its SI unit for motion along a straight line, when do we consider the acceleration to be (i) positive (ii) negative? Give an example of a body in uniform acceleration.
Answer:
Answer: Acceleration is the rate of change of velocity with respect to time or it is the rate of change of velocity in unit time. It is a vector quantity. The SI unit of acceleration is ms-2
Acceleration = Change in velocity/time
= (Final velocity – initial velocity)/time
a = \(\frac{v-u}{t}\)

If v > u, then ‘a’ is positive. If final velocity is greater than initial velocity, the velocity increase with time, the value of acceleration is positive.

If v < u, then a is negative. If final velocity is less than initial velocity
Example : The motion of a freely falling body and vertically thrown up body are the examples of uniform acceleration.
The motion of ball rolling down on an inclined plane is another example.

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

Question 2.
Distinguish between uniform motion and non
Answer:
uniform motion.

  1. An object is said to be in uniform motion if it covers equkl distances in equal intervals of time.
  2. example of uniform motion ‘train’

non-uniform motion.

  1. If a body covers unequal distances in equal interval of time (or) equal distances in a different interval of time
  2. example of non – uniform motion ‘bus’

Question 3.
Define uniform circular motion and give an example of it. Why is it called accelerated motion?
Answer:
When an object is moving with a constant speed along a circular path, the change in velocity is only due to the change in direction. Hence it is accelerated motion. Example:

  1. The earth moves around the sun in a uniform circular motion.
  2. The moon moves in uniform circular motion around the earth.

Question 4.
When a body is said to be in (i) uniform acceleration (ii) non – uniform acceleration?
Answer:
(i) A body is said to be in uniform acceleration if it travels in a straight line and its velocity increases or decreases by equal amounts in equal time intervals.
(ii) A body is said to be in non-uniform acceleration if the rate of change of its velocity is not constant i.e. differs in different time intervals.

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

Question 5.
What remains constant in uniform circular motion? And what changes continuously in uniform circular motion?
Answer:

  • Speed remains constant in a uniform circular motion.
  • Velocity changes continuously in a uniform circular motion.

Problems

Question 1.
A bus speed decreases from 50 km/h to 40 km/h in 3s, find the acceleration of the bus.
Answer:
Samacheer Kalvi 9th Science Guide Chapter 2 Motion 20

Question 2.
A car starting from rest moves with uniform acceleration of 0.2 ms-2 for 3 min. Fine the (a) speed acquired (b) the distance travelled.
Answer:
Initial speed (u) = 0 m/s
Acceleration (a) = 0.2 ms-2
Time taken (t) = 3 min = 3 × 60 = 180 s
Final velocity (v) = ?
Distance covered(s) = ?
v = u + at = 0 + 0.2 × 180 = 36 m/s
v = 36m/s
s = ut + 1/2 at2 = 0 + 1/2 × 0.2 × (180)2
= 0.1 × 32400 = 3240 m
s = 3240m

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

Question 3.
A train is travelling at a speed of 90 kmh-1. Brakes are applied so as to produce a uniform acceleration of-0.5 ms-2, find how far the train will go before it is brought to rest.
Answer:
Initial velocity of train (u) = 90 km/h = \(\frac{90,000 \mathrm{~m}}{3,600 \mathrm{sec}}=25 \mathrm{~ms}^{-1}\)
Final velocity (v) = 0 ms-1
Acceleration (a) = – 0.5 ms-2
v2 = u2+ 2as
s = (v2 – u2) / 2a = (02 – 252) / -(2 × 0.5)
s = -625/-1 = 625m
s = 625m

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

Question 4.
In a long-distance race the athletes were expected to take four rounds of the track such that the line of finish was same as the line of start. Suppose the length of the track was 300m,
Samacheer Kalvi 9th Science Guide Chapter 2 Motion 21
(i) What is the total distance to be covered by the athletes?
What is the total displacement of the athletes when they touch the finish line?
(iii) Is the motion of the athletes uniform or non- D .^starting point uniform?
(iv) Is the displacement & distance moved by an athlete at the end of the race equal?
Answer:
(i) Total distance covered = 4 × 300 = 1200 m
(ii) Displacement = 0 [final position – initial position]
(iii) Non – uniform.
∵ the direction of motion is changing while running on the track.
(iv) Both are not equal.

Question 5.
Ram swims in a 80m long swimming pool. He covers 160m in 1 min by swimming from one end to the other and back along the same straight pattern. Find the average speed and average velocity.
Answer:
Total distance = 160m
Total displacement = 0
Time taken (t) = 1 min = 60s
Samacheer Kalvi 9th Science Guide Chapter 2 Motion 22

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

Question 6.
Abus from Chennai travels to Trichy passes loo km, 160 km at 10.15 am, 11.15 am respectively. Find the average speed of the bus during 10.15 – 11.15 am.
Answer:
The distance coveredbetween 10.l5am& 11.15 am = 160 – 100
= 60km
The time interval = 1 h
Average speed = 60/1
= 60km/h

Question 7.
In a distance-time graph of two objects A & B, which object is moving with greater speed when both are moving?
Answer:
Object B makes a longer angle with the time – axis. Its slope is greater than the slope of object A. Thus the speed of B is greater than that of A.
Samacheer Kalvi 9th Science Guide Chapter 2 Motion 23

Question 8.
Find the distance covered by a particle during the time interval which the speed-time graph is-shown in figure.
Answer:
Samacheer Kalvi 9th Science Guide Chapter 2 Motion 24
Distance covered in the. time interval 0 to 20s is equal to the area of the triangle OAB.
Area of A OAB. \(\frac { 1 }{ 2 }\) × base × height
\(\frac { 1 }{ 2 }\) × 20 x 20 = 200 ms-1

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

Question 9.
A car moves 30 km in 30 min and the next 30 km in 40 min. Calculate the average speed for the entire journey.
Answer:
Answer:
Total time taken = 30 + 40 = 70 min. = \(\frac { 70 }{ 60 }\) hour
Total distance = 30 + 30 = 60 km
Samacheer Kalvi 9th Science Guide Chapter 2 Motion 25

Question 10.
A boy travels a distance of 3m due east and then 4m due north.
(a) How much is the total distance covered?
(b) What is the magnitude of the displacement?
Answer:
Samacheer Kalvi 9th Science Guide Chapter 2 Motion 26
(a) Total distance covered = 3 + 4 = 7m
(b) Net displacement: OB2 = OA2 + AB2
= 32 + 42
OB2 = 25m2
∴OB = 5m 0 3m
Net displacement = 5m

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

Question 11.
During an experiment, a signal from a spaceship reached the ground station in five seconds. What was the distance of the spaceship from the ground station? The signal
travels at the speed of light that is 3 × 108 ms-1
Answer:
Time taken = 5 seconds.
Speed of signal u = 3 × 108 m/s ?
Distance = ?
Speed = Distance / Time
∴ Distance = Speed × Time
Distance = 3 × 108 × 5 = 15 × 108 m.

Question 12.
A train travelling at a speed of 90kmph. Brakes are applied so as to produce a uniform acceleration of -0.5 ms-2. Find how far the train will go before it is brought to rest?
Answer:
Here we have
Initial velocity , u = 90km/h
\(=\frac{90 \times 1000 \mathrm{~m}}{60 \times 60 \mathrm{~s}}=25 \mathrm{~m} / \mathrm{s}\)
Final velocity, v = 0
Acceleration, a = -0.5m/s2
Thus, distance travelled = ?
We know that, v2 = u2 + 2as
Samacheer Kalvi 9th Science Guide Chapter 2 Motion 27

Question 13.
The adjacent diagram shows the velocity-time graph of the body.
a) During what time interval is the motion of the body accelerated?
Answer:
At 0 to 4 second

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

b) Find the acceleration in the time Interval mentioned in part ‘a’.
Answer:
\(\mathrm{a}=\frac{v-u}{t}=\frac{30-0}{4}=7.5 \mathrm{~m} / \mathrm{s}^{2}\)

c) What is the distance travelled by the body in the time interval mentioned ¡n part ‘a’?
Answer:Distance travelled Area under the graph
= Area of the triangle = 1/2 bh
= 1/2 × 4 × 30 = 60m

Question 14.
The following graph shows the motion of a car. What do you infer from the graph along with OA and AB? What is the speed of the car along with AB and what time it reached this speed?
a) What do you infer from the graph along OÄ and AB
Answer:
Graph along with OA: The car travels with uniform acceleration and uniform motion.
Graph along with AB : The car travels with constant speed and unaccelerated motion.
Samacheer Kalvi 9th Science Guide Chapter 2 Motion 28

b) What is the speed of the car along AB?
Answer:
Along AB : The speed of the car is constant.
From the graph, it seems the speed along AB is 72 km/hr.

c) What time it reached this speed
Answer:
It reaches this speed after 3.2 hours, that is, 3 hours, 12 minutes.

Samacheer Kalvi 9th Science Guide Chapter 2 Motion

Question 15.
From the following table, check the shape of the graph.
Samacheer Kalvi 9th Science Guide Chapter 2 Motion 29
Answer:
Samacheer Kalvi 9th Science Guide Chapter 2 Motion 30

Samacheer Kalvi 9th Science Guide Chapter 7 Heat

Tamilnadu State Board New Syllabus Samacheer Kalvi 9th Science Guide Pdf Chapter 7 Heat Text Book Back Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 9th Science Solutions Chapter 7 Heat

9th Science Guide Heat Text Book Back Questions and Answers

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

I. Choose the correct answer :

Question 1.
Calorie is the unit of
(a) heat
(b) work
(c) temperature
(d) food
Answer:
(a) heat

Question 2.
SI unit of temperature is
(a) fahrenheit
(b) joule
(c) Celsius
(d) kelvin
Answer:
(d) kelvin

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Question 3.
Two cylindrical rods of same length have the area of cross section in the ratio 2:1. If both the rods are made up of same material, which of them conduct heat faster?
(a) Both rods
(b) Rod-2
(c) Rod-1
(d) None of them
Answer:
(c) Rod-1

Question 4.
In which mode of transfer of heat, molecules pass on heat energy to neighbouring molecules without actually moving from their positions?
(a) Radiation
(b) Conduction
(c) Convection
(d) Both B and C
Answer:
(a) Radiation

Question 5.
A device in which the loss of heat due to conduction, convection and radiation is minimized is
(a) Solar cell
(b) Solar cooker
(c) Thermometer
(d) Thermos flask
Answer:
(d) Thermos flask

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

II. Fill in the blanks:

1. The fastest mode of heat transfer is ……………………….
Answer:
radiation

2. During day time, air blows from ……………………… to………………………
Answer:
sea to land

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

3. Liquids and gases are generally ……………………… conductors of heat.
Answer:
poor

4. The fixed temperature at which matter changes state from solid to liquid is called………………………
Answer:
melting point

III. Assertion and Reason type questions :

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 are true but reason is not the correct explanation of assertion.
(c) If assertion is true but reason is false.
(d) If assertion is false but reason is true.

Question 1.
Assertion : Food can be cooked faster in vessels with copper bottom.
Reason : Copper is the best conductor of heat.
Answer:
(a) Both assertion and reason are true and reason is the correct explanation of assertion

Question 2.
Assertion : Maximum sunlight reaches earth’s surface during the noon time.
Reason : Heat from the sun reaches earth’s surface by radiation.
Answer:
(b) Both assertion and reason are true but the reason is not the correct explanation of the assertion
Reason : When the sun is at its highest point, the earth’s surface absorbs more heat and retains. This heat is slowly radiated out causing increase in temperature.

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Question 3.
Assertion : When water is heated up to 100° C, there is no raise in temperature until all water gets converted into water vapour.
Reason : Boiling point of water is 10° C.
Answer:
(c) Assertion is true but the reason is false
Reason : When a substance changes from one state to another, a considerable amount of heat energy is absorbed or liberated. This energy is called latent heat.

IV. Answer briefly :

Question 1.
Define conduction.
Answer:
The process of transfer of heat in solids from a region of higher temperature to a region of lower temperature without the actual movement of molecules is called conduction.

Question 2.
Ice is kept in a double-walled container. Why?
Answer:
An ice-box is made of double wall and the space between the walls is filled with some non-conducting materials to provide heat insulation, so that the loss of heat can be minimized. Hence ice is kept in a double-walled container.

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Question 3.
How does the water kept in an earthen pot remain cool?
Answer:
An earthen pot consists of small pores from which the water inside the pot constantly seeps out and gets evaporated due to the presence of high temperatures around it. The evaporation process requires heat which is acquired from the surface of the pot, hence making the water and the pot cooler.

Question 4.
Differentiate convection,and radiation.
Answer:
Convection

  1. The process of transfer of heat in which the heated molecules of a liquid (or gas) themselves move to carry heat from the hot to the cold end is called convection.
  2. Ex : Land and sea breeze.
  3. Convection need matter to be present.

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Radiation

  1. The process of transfer of heat in which a material medium is not necessary and heat is directly transferred from the hot body to the cold body is called radiation.
  2. Ex : Transfer of heat energy from the sun.
  3. Radiation can occur even in a vacuum.

Question 5.
Why do people prefer wearing white clothes during summer?
Answer:
People prefer white or light coloured clothes during summer as they are good reflectors of heat and hence, they keep us cool.

Question 6.
What is specific heat capacity?
Answer:
Specific heat capacity of a substance is defined as the amount of heat required to raise the temperature of 1 kg of the substance by 1°C or 1 K.

Specific Heat Calculator is a free online tool that displays the amount of heat per unit mass.

Question 7.
Define thermal capacity.
Answer:

  • Heat capacity or thermal capacity is defined as the amount of heat energy required to raise the temperature of a body by 1°C. It is denoted by ‘C’.
  • C = Q/t, where C’ is the heat capacity, ‘Q’ is the quantity of heat required and ‘f’ is rise in temperature.
  • SI unit of heat capacity is J/K. It is also expressed in cal/°C, kcal/°C or J/°C.

Question 8.
Define specific latent heat capacity.
Answer:
Specific latent heat is the amount of heat energy absorbed or liberated by unit mass of a substance during change of state without causing any change in temperature.

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

V. Answer in detail :

Question 1.
Explain convection in daily life.
Answer:
Convection is the flow of heat through a fluid from places of higher temperature to places of lower temperature by movement of the fluid itself.

Hot air balloons:
Air molecules at the bottom of the balloon get heated by a heat source and rise. As the warm air rises, cold air is pushed downward and it is also heated. When the hot air is trapped inside the balloon, it rises.

Breeze :
During day time, the air in contact with the land becomes hot and rises. Now the cool air over the surface of the sea replaces it. It is called sea breeze. During night time, air above the sea is warmer. As the warmer air over the surface of the sea rises, cooler air above the land moves towards the sea. It is called land breeze.

Chimneys :
Tall chimneys are kept in kitchen and industrial furnaces. As the hot gases and smoke are lighter, they rise up in the atmosphere.

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Question 2.
What are the changes of state in water? Explain.
Answer:

  • The process of changing of a substance from one physical state to another at a definite temperature is defined as change of state.
    Samacheer Kalvi 9th Science Guide Chapter 7 Heat 1
  • For example, water molecules are in liquid state at normal temperature.
  • When water is heated to 100°C, it becomes steam which is a gaseous state of matter. On reducing the temperature of the steam it becomes water again.
  • If we reduce the temperature further to 0°C, it becomes ice which is a solid state of water. Ice on heating, becomes water again.
  • Thus, water changes its state when there is a change in temperature.
  • The process in which a solid is converted to liquid by absorbing heat is called melting or fusion.
  • The process in which a liquid is converted to solid by releasing heat is called freezing.
  • The process in which a liquid is converted to vapor by absorbing heat is called boiling or vaporization.
  • The process in which a vapour is converted to liquid by releasing heat is called condensation.
  • The process in which a solid is converted to gaseous state is called sublimation.

Question 3.
How can you experimentally prove water is a bad conductor of heat? How is it possible to heat water easily while cooking?
Answer:
Answer:
(a) Half fill a test tube with cold water. Wrap a piece of ice in wire gauze and drop it in the tube.
(i) It will sink to the bottom.
(ii) Now heat the top end of the test tube.
(iii) The water soon begins to boil at the top but the ice below has still not fully melted.
Samacheer Kalvi 9th Science Guide Chapter 7 Heat 2
This activity shows that water is a bad conductor of heat. It does not easily conduct heat from the top to the bottom of the test tube.

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

(b) It is possible to heat water easily while cooking:

  • ill a test tube with cold water.
  • Drop an ice-cube in this water.
  • Now heat the water from below.
  • You will find that the ice melts quickly.
    This shows that though water is a bad conductor of heat, heat easily flows upwards in it. This method of transfer of heat is called convection. This method is involved in cooking.

Samacheer Kalvi 9th Science Guide Chapter 7 Heat 3

VI. Numerical Problems.

Question 1.
What is the heat in joules required to raise the temperature of 25 grams of water from 0°C to 100°C? What is the heat in Calories? (Specific heat of water = 4.18 J/g°C)
answer:
Given : Mass of water m = 25g
Initial temperature T1 = 0°C
Final temperature T1 = 100°C
Change in temperature ΔT = (T2 – T1)
= (100 – 0)°C [ΔT= 100°C]
Specific heat of water C = 4.18 J/g°C
Solution:
The heat required H (in joules) = m × c × ΔT
= 25 × 4.18 × 100
= 25 × 418
= 10450 J
Heat required in calories = 1 calorie = 4.18 J
10450 J = 2497.60 calories

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Question 2.
What could be the final temperature of a mixture of 100 g of water at 90°C and 600 g of water at 20°C.
Answer:
Mass of water m1 = 100 g = 0.1 kg
Specific heat capacity of water c = 4186 J
Temperature = 90°C
Mass of water m2 = 600 g = 0.6 kg
Temperature = 20°C
Solution:
Heat lost by hot water = Heat gained by cold water
m1 × c × θ1 = m2 × c × θ2
0.1 × 4186 x (90 – TF) = 0.6 × 4186 × (TF – 20)
0.1 × (90 – TF) = (TF – 20) × 0.6
9 – 0.1 TF = 0.6TF – 12
0.7TF = 21
TF = 30°C
Final temperature of a mixture = 30°C

Question 3.
How much heat energy is required to change 2 kg of ice at 0°C into water at 20°C? (Specific latent heat of fusion of water = 3,34,000J/kg, Specific heat capacity of water = 420OJKg-1K-1
Solution:
Mass of ice m = 2 kg
Specific latent heat of fusion of water = L = 3, 34, 000 J/kg
Change in temperature ΔT = (T2 – T1)
= (20 – 0)° C
ΔT = 20° C
Specific heat capacity of water C = 4200 J Kg-1K-1
Heat energy required= m × c × ΔT + m × L
= 2 × 4,200 × 20 + 2 × 3,34,000
= 1,68,000 + 6,68,000
Heat Energy required = 8,36,000 J

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Intext Activities

ACTIVITY – 1

Take a glass of water and put some ice cubes into it. Observe it for some time. What happens? The ice cubes melt and disappear. Why did it happen? It is because heat energy in the water is transferred to the ice.

Aim:
To demonstrate transfer of heat.

Material required :
A glass of water, ice cubes.

Procedure:
Take a glass of water and put some ice cubes into it. Observe it for some time. What happens?

Observation :
The ice cubes melt and disappear. It is because heat energy in the water is transferred to the ice.

Conclusion :
Heat transfer takes place when heat energy flows from the object of higher temperature to an object with lower temperature.
[End of the activity]

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

ACTIVITY – 2

Take metal rods of copper, aluminum, brass and iron. Fix a match stick to one end of each rod using a little melted wax. When the temperature of the far ends reach the melting point of wax, the matches drop off. It’s observed that the match stick on the copper rod would fall first, showing copper as the best conductor followed by aluminum, brass and iron.

Aim :
To compare the conducting powers of various metals.

Materials required :
Metal roads of copper, aluminium, brass and iron, match stick, melted wax.

Procedure :
Fix a match stick to one end of each rod using the little melted wax. When the temperature of the far ends reach the melting point of wax, the matches drop. Observe what happens?

Observation :
The match stick on the copper rod would fall first, showing copper as the best conductor followed by aluminum, brass and then iron.

Conclusion:
Metals are good conductors of heat. Copper is the best conductor of heat.
[End of the activity]

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

ACTIVITY – 3

Drop a few crystals of potassium permanganate down to the bottom of a beaker containing water. When the beaker is heated just below the crystals, by a small flame, purple streaks of water rise upwards and fan outwards.

Aim :
To demonstrate transfer of heat through convection in liquids.

Materials required :
Crystals of potassium permanganate, beaker containing water.

Procedure :
Drop a few crystals of potassium permanganate down to the bottom of a beaker containing water, heat it with a small flame.

Observation :
When the beaker is heated, just below the crystals purple streaks of water rise upwards and fan outward.

Conclusion :
Water molecules at the bottom of the beaker receive heat energy and move upward and replace the molecules at the top.
This activity shows that the flow of heat through a fluid from places of higher temperature to places of lower temperature by movement of the fluid itself.
[End of the activity]

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

ACTIVITY – 4

Take some crushed ice cubes in a beaker and note down the temperature using thermometer. It will be 0°C. Now heat the ice in the beaker. You can observe that ice is melting to form water. Record the temperature at regular intervals and it will remain at 0°C until whole ice is converted to liquid. Now heat the beaker again and record the temperature. You can notice that the temperature will rise up to 100°C and it will retain the same even after continuous heating until the whole mass of water in the beaker is vaporized.

Aim :
To understand latent heat of the water.

Materials Required :
Crushed ice cubes, beaker and thermometer.

Procedure :
Take some crushed ice cubes in a beaker and note down the temperature using thermometer. It will be 0°C. Now heat the ice in the beaker, (i) Observe and record the temperature at regular intervals. Heat the beaker again and record the temperature.

Observation :

  • Ice is melting to form water.
  • Water will remain at 0°C until the whole ice is converted to liquid.
  • On further heating, we can observe that the temperature will rise up to 100°C and the temperature will be at 100°C even after continuous heating until the whole mass of water in the beaker is vapourized.

Conclusion :
In this activity, the temperature is constant at 0°C until entire ice is converted into liquid and again constant at 100°C until all the water is converted into vapour.
It is because, when a substance changes from one state to another, a considerable amount of heat energy is absorbed or liberated. This energy is called latent heat.

9th Science Guide Heat Additional Important Questions and Answers

I. Choose the correct answer:

Question 1.
Water is used as a coolant because it ………………….
(a) is inexpensive
(b) is easily available
(c) is a good conductor of heat
(d) has a high specific heat capacity
Answer:
(d) has a high specific heat capacity

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Question 2.
The amount of heat required to raise the temperature through 1°C is called………………………
(a) thermal energy
(b) calorie
(c) heat capacity
(d) specific heat capacity
Answer:
(c) heat capacity

Question 3.
The temperature at which a liquid gets converted into its vapour state is called its………………………
(a) melting point
(b) boiling point
(c) dew point
(d) freezing point
Answer:
(b) boiling point

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Question 4.
Sweating causes cooling because water has a………………………
(a) high specific heat
(b) low specific heat
(c) high latent heat of fusion
(d) high latent heat of vaporisation
Answer:
(d) high latent heat of vaporisation

Question 5.
Which of the following is true?
(a) 1 J = 412 calorie
(b) 1 J = 0.24 calorie
(c) 1 calorie = 4.2 J
(d) Both b and c
Answer:
(c) 1 calorie = 4.2 J

Question 6.
Ice does not melt rapidly because of
(a) high specific heat capacity
(b) high latent of fusion
(c) high heat capacity
(d) high latent heat of fusion
Answer:
(d) high latent heat of fusion

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Question 7.
Which one of the following scales has a lower fixed point at 0°C?
(a) Kelvin scale
(b) Fahrenheit scale
(c) Celsius scale
(d) All of these
Answer:
(c) Celsius scale

Question 8.
When we heat one end of an iron rod, its other end also gets heated. Can you say, Which one of the following is behind this?
(a) Convection of heat
(b) Radiation of heat
(c) Insulation of heat
(d) Conduction of heat
Answer:
(d) Conduction of heat

Question 9.
In which of the following, chemical energy is converted into heat energy?
(a) Heater
(b) Refrigerators
(c) Candle
(d) Motor
Answer:
(c) Candle

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Question 10.
On a cold day, it is hard to open the lid of a tight container. But when you gently heat the neck you can easily open the lid. why?
(a) On heating glass expands and lid contracts
(b) On heating lid expands more than the neck and thus slides easily
(c) Neck becomes slippery on heating
(d) Lid of the bottle cannot bear the heat.
Answer:
(b) On heating lid expands more than the neck and thus slides easily

Question 11.
Warm air is ………………………
(a) lighter than cold air
(b) heavier than cold air
(c) both have equal weights
(d) cannot be said
Answer:
(a) lighter than cold air

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Question 12.
The phenomenon involved in the sea breeze and the land breeze is ………………………
(a) convection
(b) conduction
(c) radiation
(d) none of these
Answer:
(a) convection

Question 13.
A liquid changes into a gas at a constant temperature known as its………………………
(a) absolute zero
(b) boiling point
(c) evaporation point
(d) dew point
Answer:
(b) boiling point

Question 14.
Copper and Iron are good conductors of heat. Which one of the following is not a good conductor of heat?
(a) Soil
(b) Aluminium
(c) Tungsten
(d) Steel
Answer:
(a) Soil

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Question 15.
The specific heat capacity of water is
(a) 4200 Jkg-1K-1
(b) 420 Jg-1K-1
(c) 0.42 Jg-1K-1
(d) 4.2 Jkg-1K-1
Answer:
(a) 4200 Jkg-1K-1

Question 16.
Two cylinders of equal height and radius are made of copper and aluminum. Which of them conducts heat faster?
(a) Copper rod
(b) Aluminium rod
(c) Both of them
(d) None of them
Answer:
(a) Copper rod

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

II. Fill in the blanks:

1. ………………………is a process which is just reverse of melting.
Answer:
Freezing

2. While a substance is undergoing a change of state, the temperature of the body remains ………………………
Answer:
same

3. A change of state is a change of a substance from………………………
Answer:
one physical state to another

4. ………………………is the degree of hotness or coldness of a body.
Answer:
Temperature

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

5. The solid, liquid, gaseous phases of water can coexist in equilibrium at………………………
Answer:
273.16K

6. The sum of the kinetic and potential energy is called the ………………………of the molecules.
Answer:
internal energy

7. ……………………… is greater for liquids than that for solids and maximum in case of gases.
Answer:
Expansion

8. When heat energy is added to a substance, the kinetic energy of its particles and so the particles ……………………… move at a higher speed.
Answer:
increase

9. When a dog keeps out its tongue and breathes hard, the moisture on the tongue turns into ………………………and it evaporates.
Answer:
water

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

10. Black marks appearing on the ceiling above a lamp or fan caused by dust being carried upwards in the air are due to………………………
Answer:
convection currents

11. ………………………is the method of heat transfer that does not require particles to carry the heat energy.
Answer:
Radiation

12. Radiation consists of ………………………waves travelling at the speed of light.
Answer:
electromagnetic

13. We can observe all the three ways of heat transfer while………………………
Answer:
burning wood

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

14. ……………………… is known as an absolute scale.
Answer:
Kelvin

15. Specific latent heat L =………………………
Answer:
Q/m

III. Match the following :

Column A Column B
1. Heat a) Heat gained or lost in the change of state with out any change in temperature
2. m × L. b) Heat gained or lost when there is no change of state
3. Temperature c) Form of energy
4. m × s × t d) SI unit of specific latent heat
5. J/Kg e) degree of hotness or coldness

Answer:
1-c, 2 -a, 3 — e, 4-b, 5-d

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

II.

Column A Column B
1. Specific heat capacity of water a) 0°C
2. Latent heat of fusion of ice b) 2260 J/g
3. Latent heat of vaporisation of water c) 100°C
4. Melting point of ice d) 4.2 J/g°C
5. Boiling point of water e) 336 J/g

Answer:
1-d, 2 -e, 3 – b, 4-a, 5-c

IV. Assertion and Reason type questions :

Question 1.
Assertion (A) : Temperature is the measure of heat energy.
Reason (R) : Energy is the capacity to do work.
(a) If both assertion and reason are true and the reason is the correct explanation of assertion.
(b) If both assertion and reason are true but reason is not the correct explanation of assertion.
(c) If assertion is true but reason is false.
(d) If assertion is false but reason is true.
Answer:
(b) Both assertion and reason are true but the reason is not the correct explanation of the assertion
Reason: It is the degree of hotness or coldness of a body.

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Question 2.
Assertion (A): Radiation is a process of transfer of heat in which a material medium is not necessary.
Reason (R): The heat from the sun reaches us through millions of miles of empty space by convection.
(a) If both assertion and reason are true and reason is the correct explanation of assertion.
(b) If both assertion and reason are true but reason is not the correct explanation of assertion.
(c) If assertion is true but reason is false.
(d) If assertion is false but reason is true.
Answer:
(c) Assertion is true but reason is false
Reason : All hot bodies radiate’ heat, therefore from the sun the heat comes to us by radiation.

Question 3.
Assertion (A) : Heat energy is transferred from one body to another due to a
temperature difference between them.
Reason (R) : Heating a substance causes a rise in temperature.
(a) If both assertion and reason are true and reason is the correct explanation of assertion.
(b) If both assertion and reason are true but reason is not the correct explanation of assertion.
(c) If assertion is true but reason is false.
(d) If assertion is false but reason is true.
Answer:
(b) Both assertion and reason are true but reason is not the correct explanation of assertion
Reason : Heat energy is more in hot substances and less in cold substances and flows from hot substances to cold substances.

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Question 4.
Assertion (A) : When a very hot liquid is poured into a thick glass tumbler it cracks.
Reason (R) : Unequal expansion of the inner and outer glass walls causes the glass to crack.
(a) If both assertion and reason are true and reason is the correct explanation of assertion.
(b) If both assertion and reason are true but reason is not the correct explanation of assertion.
(c) If assertion is true but reason is false.
(d) If assertion is false but reason is true.
Answer:
(a) Both assertion and reason are true and reason is the correct explanation of assertion

V. Very short answer type questions.

Question 1.
What is the other name of heat capacity?
Answer:
Thermal capacity.

Question 2.
Define one calorie.
Answer:
The amount of heat energy required to raise the temperature of 1 g water by 1°C is called one calorie.

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Question 3.
What is the relation between calorie and Joule?
Answer:
1 Calorie = 4.186 J
= 4.2 J

Question 4.
Name a device that prevents loss of energy (or gain) by conduction, convection and radiation.
Answer:
Thermos flask.

Question 5.
Which factor determines the direction of flow of heat from one body to another?
Answer:
Temperature.

Question 6.
Who introduced the term latent heat?
Answer:
Joseph Black in 1750.

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Question 7.
What is the minimum possible temperature? Is there also a maximum possible temperature?
Answer:
The minimum possible temperature is OK. There is no limit to maximum temperature.

VI. Answer briefly :

Question 1.
Heat gained by a body depends upon which factors?
Answer:

  • Mass of the body
  • Change in temperature of the body
  • Nature of the material of the body.

Question 2.
Water is used as a coolant in car radiators. Why?
Answer:
Water is used as a coolant in car radiators because it has high specific heat capacity. As a result, it can absorb large amounts of heat from the car engine without any substantial increase in its temperature.

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Question 3.
What do you mean by thermal equilibrium?
Answer:
When two bodies at different temperatures are kept in contact with each other, then heat energy flows from the hot body to the colder one.

It means that the hot body will lose heat and the cold body will gain heat till they reach a common temperature. This state is called thermal equilibrium.

Question 4.
Define latent heat of fusion?
Answer:
Heat energy is absorbed by a solid during melting and an equal amount of heat energy ‘ is liberated by the liquid during freezing, without any temperature change. It is called latent heat of fusion.

Question 5.
Why are burns caused by steam more painful than those caused by boiling water at the same temperature?
Answer:

  • When steam hits our skin, it condenses to water and then cools down to the temperature of skin.
  • Now, the energy released will be due to latent heat and fall in temperature.
  • Whereas when boiling water hits our skin, there is no phase transition but only fall in temperature and the heat transferred to skin will be only due to cooling.
  • Also, the loss of energy that is released from steam hitting our skin occurs quickly and in a small localized area, therefore causing damage to our cells.

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Question 6.
What do you mean by solidification or deposition?
Answer:
Solidification is the process in which a gas directly condenses into its solid state without going into liquid state Ex : Carbon dioxide gas gets converted into dry ice.

Question 7.
Define absolute zero.
Answer:
The temperature at which the pressure and volume of a gas theoretically reaches zero is called absolute zero.

Question 8.
Give some practical applications of conduction in daily life.
Answer:

  • Metals are good conductors of heat. So, aluminium is used for making utensils to cook food quickly.
  • Mercury is used in thermometers because it is a good conductor of heat.
  • We wear woolen clothes in winter to keep ourselves warm. Air, which is a bad conductor, does not allow our body heat to escape.

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Question 9.
Give some practical applications of radiation.
Answer:

  • White or light colored clothes are good reflectors of heat. They keep us cool during summer.
  • The bottom surface of cooking utensils is blackened because the black surface absorbs more heat from the surrounding.
  • The surface of the airplane is highly polished because it helps to reflect most of the heat radiation from the sun.

Question 10.
Can convection take place in solids? Why?
Answer:
No. The molecules in a solid are only free to vibrate about their fixed positions. For convection to take place, the molecules need to move to carry the heat with them. Hence, convection cannot take place in solids.

Question 11.
In winters, when the sun suddenly goes behind the clouds we feel cold, can you say why?
Answer:
The clouds cut off the radiant heat from the sun.

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

VII. Answer in detail :

Question 1.
Give the difference between heat and temperature.
Answer:
Heat

  1. Heat is a form of energy due to which we feel hot or cold.
  2. Its SI unit is joule (J)
  3. It depends upon mass, nature and temperature of the body.
  4. It is a form of energy.
  5. It is measured by a calorimeter.

Temperature :

  1. The degree of hotness or coldness of a body is known as temperature.
  2. Its SI unit is kelvin (K).
  3. It does not depend upon mass, nature and temperature of the body.
  4. It is a condition that determines the direction of flow of heat.
  5. It is measured by a thermometer.

Question 2.
Give some practical applications of specific latent heat of ice.
Answer:
Specific latent heat of ice is very high (i.e.) 336 J/g.

  • Due to high specific latent heat of ice, snow on mountains do not melt as a whole, but melts gradually into water with the heat of the sun.
    If the specific latent heat of ice would not have been so high, all the snow would have melted very quickly and there would have been floods in the rivers.
  • All the water in lakes and ponds in cold places do not freeze all at the same time. If freezes slowly and keeps the surrounding moderate.
  • Drinks are cooled more effectively by ice pieces at 0°C and not by water at 0°C. This is because 1 g of ice takes away 336 J of heat from the drink to melt into water at 0°C.

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Question 3.
600 g of copper at 50°C is mixed with lOOOg water at 20°C. Find the final temperature of the mixture. Specific heat capacity of copper is 0.4 Jg-1°C-1 and that of water is 4.2 Jg-1°C-1
Solution :
Let final temperature of the mixture of copper and water = x °C
For copper:
Mass of copper m1 = 600g
Specific heat capacity of copper c1 = 0.4Jg-1°C-1
Initial temperature of copper t1 = 50°C
Final temperature of copper t2 = x°C
Fall in temperature Δt = (50 – x)°C
Heat lost by copper = m1 × c1 × t
= 600 × 0.4 × (50 – x)

For water :
Mass of water m2 = 1000g
Specific heat capacity of water c2 = 4.2Jg-1°C-14
Initial temperature of water t1 = 20°C
Final temperature of water t2 = x°C
Rise in temperature Δt = (x – 20)°C
Heat gained by water = m2 × c2 × t
= 100 × 4.2 × (x – 20)

According to the principle of calorimetry,
Heat lost by copper = Heat gained by water
600 × 0.4 × (50 – x) =1000 x 4.2 x (x – 20)
240 × (50 – x) = 4200 ( x- 20)
12,000 – 240x = 4200x-84000
4200x + 240x =12000 + 84000
4440 = 96000
x = \(\frac{96000}{4440}=21.6\)
So, final temperature of mixture of water and copper x = 21.6°C

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Question 4.
Compare heat capacity and specific heat capacity.
Answer:
Specific heat capacity :

  1. It is the heat required to raise the temperature of 1g of a substance through 1°C.
  2. It does not depend on the mass of the body It depends on the mass of the body
  3. Its unit is Jkg-1 °C-1

Heat capacity

  1. It is the heat required to raise the temperature of a given mass of substance through 1°C.
  2. It depends on the mass of the body
  3. Its unit is J°C-1.

Question 5.
Explain the following effects of heat.
(i) Expansion
(ii) Change in temperature
(iii) Change in state
(iv) Chemical changes.
Answer:
(i) Expansion:
When heat is added to a substance, the molecules gain energy and vibrate and force other molecules apart. As a result, expansion takes place. You would have seen some space being left in railway tracks. It is because, during summer time, more heat causes expansion in tracks. Expansion is greater for liquids than for solids and maximum in case of gases.

(ii) Change in temperature :
When heat energy is added to a substance, the kinetic energy of its particles increases and so the particles move at higher speed. This causes rise in temperature. When a substance is cooled, that is, when heat is removed, the molecules lose heat and its temperature falls.

(iii) Change in state :
When you heat ice cubes, they become water and water on further heating changes into vapour. So, solid becomes liquid and liquid becomes gas, when heat is added. The reverse takes place when heat is removed.

(iv) Chemical changes :
Since heat is a form of energy it plays a major role in chemical changes. In some cases, chemical reactions need heat to begin and also heat determines the speed at which reactions occur. When we cook food, we light the wood and it catches fire and the food particles become soft because of the heat energy. These are all the chemical changes taking place due to heat.

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

VIII. Numerical Problems

Question 1.
What is the amount of heat required to raise the temperature of 5 kg of iron from 30°C to 130°C? Specific heat capacity of iron = 483 Jkg-1C-1.
Solution :
Mass of iron m = 5kg
Initial temperature t1 = 30°C
Final temperature t2 = 130°C
Rise is temperature Δt = (t2 -t1) = 130 – 30 = 100°C
Specific heat capacity of iron c = 483Jkg-1°C-1
Q = m × c × Δt
= 5 × 483 × 100
= 2,41,500J

Question 2.
Calculate the amount of heat required to convert 200g of ice at 0°C into the water at 0°C Specific latent heat of fusion of ice = 336 Jg-1
Solution :
Mass of ice m = 200g
Specific latent heat of fusion of ice L = 336Jg-1
Heat required Q = mL
= 200 × 336
Q = 67,200 J

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Question 3.
2875 J of heat is required to melt 115 g of lead at its melting point. Calculate the specific latent heat capacity of fusion of lead.
Solution:
Mass of lead m = 115 g
Heat required Q = 2875 J
Specific latent heat of lead L =?
We know that Q = m L
L = \(\frac{Q}{m}=\frac{2875}{115}\)
= 25 Jg-1

Question 4.
What will be the final temperature if 1,68,000 J of heat is absorbed by 2 kg of water at 30°C?
Solution :
Heat absorbed Q = 1,68,000 J
m = 2kg
Initial temperature t1 = 30°C
Let final temperature t2 = x°C
Rise is temperature Δt = (t2 – t1)
= (x – 30)°C
Specific heat capacity of water C = 4200 J kg-1°C-1
We know that Q = m × c × Δt
1,68,000 = 2 × 4200 × (x – 30 )
x – 30 = \(\frac{1,68,000}{2 \times 4200}\)
x- 30 = 20
x = 30 + 20
= 50°C
So, the final temperature of water = 50°C

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

Question 5.
A metal ball of heat capacity 50J/°C loses 2000 J of heat. By how much will its temperature fall?
Solution :
Heat capacity of ball = 50 J °C-1
Heat lost Q = 200 J
Fall in temperature t =?
Samacheer Kalvi 9th Science Guide Chapter 7 Heat 4

IX. Convert the following

1. 100°F to °C
Solution:
T(°C) = (T(°F) – 32) /1.8
T(°C) = (100°F – 32)
T(°C) = 37.7 °C

2. 40°C to Fahrenheit (°F)
Solution :
T(°F) = (T(°F) × 1.8) + 32
= 40°C × 1.8 + 32
= 72 + 32
T(°F) = 104°F

3. 35°C to Kelvin
Solution :
T(K) = T(°C) +273.15
= 35 + 273.15
T(K) = 308.15 K

4. 80°K to °C
Solution :
T(°C) = T(K) – 273.15
T(°C) = 80-273.15
T(°C) = 193.I5 °C

Samacheer Kalvi 9th Science Guide Chapter 1 Measurement

X. Define the following :

1. Heat: Heat is a form of energy which transfers from the higher temperature region to the lower temperature region of a body.
2. Conduction: The process of transfer of heat in solids from a region of higher temperature
to a region of lower temperature without the actual movement of molecules is called conduction.
3. Convection: Convection is the flow of heat through fluid from places of higher temperature to places of lower temperature by the movement of the fluid itself.
4. Radiation: Radiation is a method of heat transfer that does not require particles to carry the heat energy.
5. Temperature: Temperature is the degree of hotness or coolness of a body.
6. Specific heat capacity: Specific heat capacity of a substance is defined as the amount of heat required to raise the temperature of 1 kg of the substance by 1° C or 1 K.
7. Heat capacity or thermal capacity: Heat capacity is the heat required to raise the temperature of the entire mass of the body by 1° C.
8. Change of state: The process of changing of a substance from one physical state to another at a definite temperature is known as change of state.
9. Melting or fusion: The process in which a solid is converted to a liquid by absorbing heat is called melting or fusion.
10. Boiling: Th e process in which a liquid is converted to vapor by absorbing heat is called boiling or vaporization.
11. Sublimation: Th e process in which a solid is converted to a gaseous state is called sublimation.
12. Latent heat: Thus, latent heat is the amount of heat energy absorbed or released by a substance during a change in its physical states without any change in its temperature.
13. Specific latent heat: Specific latent heat is the amount of heat energy absorbed or liberated by the unit mass of a substance during a change of state without causing any change in temperature.

Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues

Tamilnadu State Board New Syllabus Samacheer Kalvi 9th Science Guide Pdf Chapter 18 Organization of Tissues Text Book Back Questions and Answers, Notes.

Samacheer Kalvi 9th Science Solutions Chapter 18 Organization of Tissues

9th Science Guide Organization of Tissues Text Book Back Questions and Answers

I. Choose the correct answer:

Question 1.
The tissue composed of living thin walled polyhedral cell is
(a) parenchyma
(b) pollenchyma
(c) pclerenchyma
(d) none of above
Answer:
(d) none of above

 Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues

Question 2.
The fibres consists of
(a) parenchyma
(b) sclerenchyma
(c) collenchyma
(d) none of above
Answer:
(b) sclerenchyma

Question 3.
Companion cells are closely associated with
(a) sieve elements
(b) vessel elements
(c) trichomes
(d) guard cells
Answer:
(a) sieve elements

 Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues

Question 4.
Which of the following is a complex tissue?
(a) Parenchyma
(b) Collenchyma
(c) Xylem
(d) Sclerenchyma
Answer:
(c) Xylem

Question 5.
Aerenchyma is found in
(a) epiphytes
(b) hydrophytes
(c) halophytes
(d) xerophytes
Answer:
(b) hydrophytes

 Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues

Question 6.
Smooth muscles occur in
(a) uterus
(b) artery
(c) vein
(d) all of the above
Answer:
(d) all of the above

Question 7.
Nerve cell does not contains
(a) axon
(b) nerve endings
(e) tendons
(d) dendrités
Answer:
(c) tendons

 Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues

II. Match the following.

Question 1.

Sclereids Chlorenchyma
Chloroplast Sclerenchyma
Simple tissue Collenchyma
Companion cell Xylem
Tracheids Phloem

Answer:

Sclereids Sclerenchyma
Chloroplast Chlorenchyma
Simple tissue Collenchyma
Companion cell Phloem
Tracheids Xylem

III Fill in the blanks :

1. ……………. tissues provide mechanical support to organs.
Answer:
Compound epithelium

 Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues

2. Parenchyma, Collenchyma, Sclerenchyma are ……………. type of tissue.
Answer:
simple

3. ……………. and ……………… are complex issues.
Answer:
Xylem, phloem

4. Epithelial cells with cilia are fóund in ……………….. of our body
Answer:
trachea or windpipe

 Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues

5. Lining of the small intestine is made up of …………………..
Answer:
columnar epithelium

IV. State whether true or false. If false, correct the statement :

1. Epithelial tissue is protective tissue in an animal body.
Answer:
True.

2. Bone and cartilage are two types of areolar connective tissue.
Answer:
False.
Correct statement: Bone and cartilage are two types of supportive connective tissue.

3. Parenchyma is a simple tissue.
Answer:
True.

 Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues

4. Phloem is made up of tracheids.
Answer:
False.
Correct statement: Phloem is made up of sieve tubes.

5. Vessels are found in collenchyma.
Answer:
False.
Correct statement: Vessels are found in the xylem.

 Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues

V. Answer briefly :

Question 1.
What are intercalary meristems? How do they differ from other meristems?
Answer:
Intercalary meristem lies between the region of permanent tissues and is part of primary meristem which is detached due to formation of intermittent permanent tissues. It is found either at the base of leaf e.g. Pinus or at the base of intemodes e.g. grasses.

Question 2.
What is complex tissue? Name the various kinds of complex tissues.
Answer:

  • Complex tissues are made of more than one type of cells that work together as a unit.
  • Complex tissues consist of parenchyma and sclerenchyma cells. However, collenchymatous cells are not present in such tissues.
  • Common examples are xylem and phloem.

 Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues

Question 3,.
Mention the most abundant muscular tissue found in our body. State its function.
Answer:
Connective tissue is the most abundant and widely distributed tissue. It provides a structural framework and gives support to different tissues forming organs.

Question 4.
What is skeletal connective tissue? How is it helpful in the functioning of our body?
Answer:
The supporting or skeletal connective tissues forms the endoskeleton of the vertebrate body. They protect various organs and help in locomotion. The supportive tissues include cartilage and bone.

 Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues

Question 5.
Why should gametes be produced by meiosis during sexual reproduction?
Answer:
Meiosis is important as it produces gametes i.e., male or female germ cells. During meiosis, a germ cell or gamete divides to make four new sex cells. As a result of fertilization two gamates join together to form an egg or zygote. Therefore only if gametes are produced, fertilization can take place.

Question 6.
In which stage of mitosis the chromosomes align in an equatorial plate? How?
Answer:
Metaphase (meta – after) The duplicated chromosomes arrange on the equatorial plane and form the metaphase plate. Each chromosome gets attached to a spindle fibre by its centromere. The centromere of each chromosome divides into two each being associated with a chromatid.

 Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues

VI. Answer in detail:

Question 1.
What are the permanent tissues? Describe the different types of simple permanent tissues.
Answer:
Permanent tissues:
Permanent tissues are those in which, growth has stopped either completely or for the time being. At times, they become meristematic partially or wholly.

Different types of simple permanent tissue :
Simple tissue: Simple tissue is homogeneous-composed of structurally and functionally similar cells. Eg : Parenchyma, collenchyma, and sclerenchyma.

Parenchyma:

Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues 1

  • Parenchyma are simple permanent tissue composed of living cells.
  • Parenchyma cells are thin-walled, oval, rounded, or polygonal in shape with well-developed spaces among them.
  • In aquatic plants, parenchyma possesses intercellular air spaces and is named as aerenchyma.
  • When exposed to light, parenchyma cells may develop chloroplasts and are known as chlorenchyma.

Functions:

  • Parenchyma may store water in many succulent and xerophytic plants.
  • It also serves the functions of storage of food reserves, absorption, buoyancy, secretion, etc

Collenchyma:
Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues 2

  • Collenchyma is a living tissue found beneath the epidermis.
  • Cells are elongated with unevenly thickened non-lignified walls. Cells have rectangular oblique or tapering ends and persistent protoplast.
  • They possess thick primary non-lignified walls.
    Functions: They provide mechanical support for growing organs.

Sclerenchymà:

  • Scierenchyma consists of thick-walled cells which are often lignified.
  • Scierenchyma cells do not possess living protoplasts at maturity. Scierenchyma cells are grouped into

(i) fibers and (ii) sclereids.
Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues 3

Fibres : Elongated scierenchymatous cells, usually with pointed ends. Their walls are lignified. Fibres are abundantly found in many plants. Eg. Jute.
Sclereids:

  • Sclereids are widely distributed in plant body. They are usually broad, may occur in single or in groups.
  • Sclereids are isodiametric, with lignified walls. Pits are prominent and seen along the walls.
  • Lumen is filled with wall materials. Sclereids are also common in fruits and seeds.

 Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues

Question 2.
Write about the elements of Xylem.
Answer:
Xylem is a conducting tissue which conducts water, mineral nutrients upward from root to leaves. Xylem is also meant for mechanical support to the plant body. Xylem is composed of different kinds of elements. They are

  1. xylem tracheids
  2. xylem fibres
  3. xylem vessels and
  4. xylem parenchyma.

(i) Xylem tracheids: They are elongated or tube-like dead cells with hard, thick and lignified walls. Their ends are tapering, blunt or chisel-like. These cells are devoid of protoplast. They have large lumen without any content. Their function is conduction of water and providing mechanical support to the plant.

(ii) Xylem fibers: These cells are elongated, lignified and pointed at both the ends. Xylem fibres help in the conduction of water and nutrients from root to the leaf and also provide mechanical support to the plant.

(iii) Xylem vessels: They are long cylindrical, tube-like structures with lignified walls and wide central lumen. These cells are dead as these do not have protoplast. They are arranged in longitudinal series in which the partitioned walls (transverse walls) are perforated, and so the entire structure looks-like a water pipe. Their main function is the transport of water and minerals from root to leaf, and also to provide mechanical strength.

(iv) Xylem parenchyma: Its cells are living and thin-walled. The main function of xylem parenchyma is to store starch and fatty substances.

Question 3.
List out the differences< between mitosis and meipsis.
Answer:

Mitosis Meiosis
1. Occurs in somatic cells. Occurs in reproductive cells
2. Involved in growth and occurs continuously throughout life. Involved in gamete formation only during the reproductively active age.
3. Consists of single division. Consists of two divisions.
4. Two diploid daughter cells are formed. Four haploid daughter cells are formed.
5. The chromosome number in the daughter cell is similar to the parent cell (2n). The chromosome number in the daughter cell is just half (n) of the parent cell.
6. Identical daughter cells are formed. Daughter cells are not similar to the parent cell and are randomly assorted.

 Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues

VII. Higher Order Thinking Skills :

Question 1.
What is the consequence that occurs if all blood platelets are removed from the blood?
Answer:
Blood platelets play a major role in the clotting of blood whenever there is a wound/injury. If blood platelets are removed from the blood, clotting of blood will not occur. In case of any injury/surgery etc., blood will be lost from the body in excess and may even prove to be fatal.

2. Which are not true cells in the blood? Why?
Answer:
Red blood cells or erythrocytes cannot be considered as true cells since they have a nucleus only in the early stages. A mature RBC lacks a nucleus which is the controlling centre of all living cells.

Intext Activities

ACTIVITY – 1
Rinse your mouth with water. Using a toothpick or ice-cream stick, scrap superficial cells from the inner side of the cheek and spread it on a clean glass slide. Dry the glass slide with the scrap cells taken from the inner side of the cheek. Add two drops of methylene blue stain. Identify the cells under low and high power of the microscope.
Solution:
1. Large irregularly shaped cells with cell walls.
2. Dark blue nucleus at the central part of each cell.
3. Lightly stained cytoplasm colour in each cell.

9th Science Guide Organization of Tissues Additional Important Questions and Answers

I. Choose the correct answer :

Question 1.
A meristematic tissue consists of
(a) immature cells that are capable of undergoing cell division.
(b) mature cells
(c) non-living cells
(d) sclerenchyma cells
Answer:
(a) immature cells that are capable of undergoing cell division

Question 2.
Two long bones of the hand are dislocated in a person who met with an accident. Which among the following may be the possible reason?
(a) Tendon injury
(b) Break of skeletal muscle
‘(c) Ligament tear
(d) Rupture of Areolar tissue
Answer:
(c) Ligament tear

 Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues

Question 3.
Non-striated muscles are found in
(a) blood vessels
(b) gastric glands
(c) urinary bladder
(d) all of these
Answer:
(d) all of these

Question 4.
Which of the following is not found in a neuron?
(a) Sarcolemma
(b) Dendrite
(c) Myelin sheath
(d) Axon
Answer:
(a) Sarcolemma

Question 5.
Cylindrical, unbranched multinucleated cells are
(a) striated muscle cells
(b) smooth muscles
(c) cardiac muscles
(d) none of the above.
Answer:
(a) striated muscle cells

 Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues

Question 6.
The matrix of the bone is rich in
(a) elastin
(b) reticular fibres
(c) collagen
(d) myosin
Answer:
(c) collagen

Question 7.
Which muscles act involuntarily?
(i) Striated muscles
(ii) Smooth muscles
(iii) Cardiac muscles
(iv) Skeletal muscles
(a) (i) and (ii)
(b) (ii) and (iii)
(c) (iii) and (iv)
(d)(i) and (iv)
Answer:
(b) (ii) and (iii)

Question 8.
Tendon connects
(a) cartilage with muscles
(b) bone with skeletal muscles
(c) ligament with muscles
(d) bone with bone
Answer:
(b) bone with skeletal muscles

 Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues

Question 9.
In a certain type of cell division, the diploid number of chromosomes is reduced to half. This kind of division occurs in
(a) testis
(b) ovary
(c) both ovary and testis
(d) all body cells
Answer:
(c) both ovary and testis

Question 10.
……………… is derived from the ground meristem.
(a) Cortex
(b) Epidermis
(c) Xylem
(d) Cambium
Answer:
(a) Cortex

Question 11.
The function of phloem fibres is …………….to the plant body
(a) passage of food
(b) Store food
(c) mechanical strength
(d) preparation of food
Answer:
(c) mechanical strength

 Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues

Question 12.
The …………….. epithelium is also known as pavement membrane.
(a) Ciliated
(b) Squamous
(c) Cuboidal
(d) Glandular
Answer:
(b) Squamous

Question 13.
Elastic structures that connect bones to bones are called ………………..
(a) muscles
(b) tendons
(c) ligaments
(d) areolar tissue
Answer:
(c) ligaments

 Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues

Question 14.
………………… is seen in unicellular animals.
(a) Mitosis
(b) meiosis
(e) Amitosis
(d) none of the above
Answer:
(c) Amitosis

Question 15.
The disappearance of spindle fibres is seen in …………….
(a) metaphase
(b) prophase
(c) anaphase
(d) telophase
Answer:
(d) telophase

Question 16.
The ………………… is a single, long fiber like process that develops from the cyton.
(a) dendron
(b) axon
(c) dendrite
(d) neurilemma
Answer:
(b) axon

 Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues

Question 17.
Bouquet stage refers to ……………..
(a) diakinesis
(b) leptotene
(c) zygotene
(d) pachytene
Answer:
(b) leptotene

Fill in the blanks :

1. The ……………. tissues are made up of more than one type of cells and these woks together as a unit.
Answer:
complex

2. The two types of skeletal connective tissues are ……………. and …………….
Answer:
bone, cartilage

3. Humans have 46 chromosomes. Their sperms and eggs will have ……………. chromosomes each.
Answer:
23

 Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues

4. During pairing of chromosomes in meiosis, the …………….. chromosomes come to lie side by side.
Answer:
homologous

5. The word meristem is derived from a Greek word ………………
Answer:
Meristos

6. Cork cambium is an example of ……………… meristem.
Answer:
secondary

 Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues

7. The meristem found at the base of intemodes is called ……………….
Answer:
intercalary meristem

8. In apple, paranchyma stores ………………
Answer:
sugar

9. Fibres are extensively longer ranging from 20 mm to 550 mm ……………….
Answer:
corchorus capsularis (jute)

10. During mieosis in pachytene, stages the paired chromosomes are called ………………….
Answer:
bivalents

 Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues

11. Mitosis was discovered by …………………..
Answer:
Flemming

12. Both smooth and cardiac muscles are …………….. in nature.
Answer:
involuntary

13. ………………. is a non-flexible skeletal connective tissue.
Answer:
Bone

 Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues

14. ……………. acts as a fat reservoir.
Answer:
Adipose tissue

15. …………….. epithelium is seen in sweat glands.
Answer:
Cuboidal

16. Genetic variations occur in meiosis because of …………….
Answer:
crossing over

III. State whether True or false. If false, write the correct statement:

1. Epithelial layer does not allow regulation of materials between the body and the external environment.
Answer:
False.
Correct statement: Epithelium is involved in the absorption and elimination of waste.

2. Striated and non-striated tissues are types of epithelial tissues.
Answer:
False.
Correct statement: They are types of muscular tissues.

 Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues

3. Spindle formation occur in amitosis.
Answer:
False.
Correct statement: Spindle formation occur in mitosis.

4. Movement of food in the alimentary canal is because of cardiac muscles.
Answer:
False.
Correct statement: Movement of food is alimentary canal by the rhythmic con t no-tom and relaxation of the muscular nails of the alimentary canal.
Correct statement: Movement of food in the alimentary canal.

5. A mature RBC lacks a nucleus.
Answer:
True

6. Excessive pulling of bones causes a sprain.
Answer:
False.
Correct statement: Sprain is caused by excessive pulling of ligaments.

 Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues

7. Glandular epithelium gives a stratified appearance.
Answer:
False.
Correct statement: Compound epithelium given a stratified appearance.

8. Sieve cells have no companion cells.
Answer:
True.

9. Conduction can be bidirectional in phloem tissue.
Answer:
True.

10. White blood corpuscles contain respiratory pigment hemoglobin.
Answer:
False.
Correct statement: Red blood corpuscles contain respiratory pigment hemoglobin.

 Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues

IV. Assertion and Reason type:

Direction: In each of the following questions, a statement of Assertion is given and a corresponding statement of Reason is given just below it. Of statements, given below, mark the correct answer as
(a) Both Assertion and Reason are true and Reason is the correct explanation of Assertion.
(b) Both Assertion and Reason are true that Reason is not the correct explanation of Assertion.
(c) Assertion is true but Reason is false.
(d) Both Assertion and Reason are false.

Question 1.
Assertion: Non-striated muscles are said to be voluntary in nature.
Reason: Non-striated muscles are under the control of our will.
Answer:
(d) Both Assertion and Reason are false

Question 2.
Assertion: Materials are exchanged between epithelial and connective tissues by diffusion.
Reason: Blood vessels are absent in epithelial tissue.
Answer:
(a) Assertion and Reason are true and Reason is the correct explanation of Assertion

 Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues

V. Answer in one or two sentences :

Question 1.
Name the two types of sclerenchyma cells.
Answer:
Sclerenchyma cells are grouped into

  1. fibres and
  2. sclereids.

Question 2.
Name the components of xylem and phloem.
Answer:
Xylem is composed of :

  • Xylem tracheids
  • Xylem fibres
  • Xylem vessels
  • Xylem parenchyma

Phloem is composed of:

  • Sieve elements
  • Companion cells
  • Phloem fibres
  • Phloem parenchyma

Question 3.
Name the tissue that connects muscle to bone in humans.
Answer:
Tendons join skeletal muscles to bones in our body.

 Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues

Question 4.
Name the tissue that stores excess fat in our body.
Answer:
Adipose tissue.

Question 5.
Name the connective tissue with a fluid matrix.
Answer:
Blood and lymph

Question 6.
Name the tissue present in the brain.
Answer:
Nervous tissue.

Question 7.
What is plate meristem?
Answer:
These cells divide into two planes resulting in an increase in the area of an organ.
Eg: Leaf formation.

 Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues

Question 8.
Differentiate collenchyma and sclerenchyma.
Answer:

Collenchyma Sclerenchyma
It consists of living cells It consists of dead cells
Cells contain protoplasm Cells do not possess living protoplast
Cell walls are non-lignified Cell walls are lignified

Question 9.
Mention the type of epithelium seen in alveoli of lungs.,
Answer:
Squamous epithelium.

Question 10.
Name the supportive connective tissues.
Answer:
Cartilage and bone

Question 11.
Name the cartilage cells present in the matrix.
Answer:
Chondrocytes.

 Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues

Question 12.
What is the role of RBC?
Answer:
RBC contains a respiratory pigment called hemoglobin which is involved in the transport of oxygen to tissues.

Question 13.
Mention the stages of meiotic Prophase -I.
Answer:
Leptotene, Zygotene, Pachytene, Diplotene, Diakinesis.

Question 14.
What is the significance of Meiosis?
Answer:
The constant number of chromosomes in a given species is maintained by meiotic division.

 Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues

Question 15.
Draw a shoot apex and label the meristem’s parts.
Answer:
Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues 4

VI. Short Answer Type :

Question 1.
How would you differentiate meristematic and permanent tissue?
Answer:

Meristematic tissue Permanent tissue
Cytoplasm is dense, and vacuoles are nearly absent. Usually large central vacuole present in living permanent cells.
Intercellular spaces absent. Intercellular spaces present.
Component cells are small, spherical or polygonal and undifferentiated. Component cells are large, differentiated with different shapes.
Cell wall is thin and elastic. Cell wall is thick.
Nucleus is large and prominent. Nucleus is less conspicuous.
Cells grow and divide regularly. Cells do not normally divide.
Provides mechanical support and elasticity to the plant body. Provides only mechanical support.

Question 2.
Differentiate fibres from sclereids.
Answer:

Sclereids Fibres
Usually broad Elongated narrow thread-like
End walls blunt Usually with pointed ends.
Occur singly Occur in bundles
Deep pits Narrow pits

 Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues

Question 3.
Which tissue is the main component of tendons and ligaments? How do they differ in function?
Answer:
Dense Connective Tissue is a fibrous connective tissue densely packed with fibres and fibroblasts. It is the principal component of tendons and ligaments.

a. Tendons: Cord-like, strong, structures that join skeletal muscles to bones. Tendons have great strength and limited flexibility. They consist of parallel bundles of collagen fibres, between which are present rows of fibroblasts.

b. Ligaments: They are highly elastic structures and have great strength which connects bones to bones. They contain very little matrix. They strengthen the joints and allow normal movement.

Question 4.
What are the fibres present in the connective tissue proper?
Answer:
Connective tissue proper: Connective tissue proper consists of collagen fibres, elastin fibres and fibroblast cells.

Areolar tissue: It has cells and fibres loosely arranged in a semi-fluid ground substance called matrix. It takes the form of fine threads crossing each other in every direction leaving small spaces called areolae. It joins skin to muscles, fills space inside organs and is found around muscles, blood vessels and nerves. It helps in repair of tissues after injury and fixes skin to underlying muscles.

Adipose Tissue: Adipose tissue is the aggregation of fat cells or adipocytes spherical or oval in shape. It serves as fat reservoir. The matrix consists of collagen fibres, elastin fibres and fibroblast cells.

 Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues

Question 5.
How are collagen fibres organized in dense connective tissues?
Answer:

  • Dense connective tissue is a fibrous connective tissue densely packed with fibres and fibroblasts. It is the principal component of tendon and ligaments.
  • Tendons consist of parallel bundles of collagen fibres, between which are present rows of fibroblasts.
  • Ligaments are highly elastic structures and contain very little matrix.

Question 6.
Write one point of difference between
a) Bone and cartilage.
b) Simple and compound epithelial tissue.
Answer:
a)

Bone Cartilage
It is solid, rigid, and strong, non-flexible skeletal connective tissue. It is a soft, semi-rigid, flexible skeletal connective tissue.
The matrix of the bone is in the form of concentric rings called lamellae The matrix is composed of large cartilage cells called chondrocytes

b)

Simple epithelium tissue Çompound epithelium tissue
It is composed of a single layer of cells
resting ón a basement membrane.
It is composed of several layers of cells.
Only the cells of the deepest layer rest
on the basement membrane.

Question 7.
Why is blood considered to be a fluid connective tissue?
Answer:

  • The blood and the lymph are the fluid connective tissues which link different parts of the body. The cells of the connective tissue are loosely spaced and are embedded in an intercellular matrix.
  • Blood contains corpuscles which are red blood cells (erythrocytes), white blood cells (leucocytes), and platelets. In this fluid connective tissue, blood cells move in a fluid matrix called plasma. The plasma contains inorganic salts and organic substances. It is a main circulating fluid that helps in the transport of nutrient substances.

 Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues

Question 8.
Give the sequence of the events occurring during prophase of mitosis.
Answer:

  • During this stage, chromosomes become short and thick and are clearly visible inside the nucleus.
  • Centrosome splits into two daughter centrioles and occupies opposite poles of the cell.
  • Each centriole is surrounded by aster rays. Spindle fibres appear between the two centrioles.
  • The nuclear membrane and nucleolus disappear gradually.

Question 9.
Why is meiosis called reductional division and mitosis as equational division?
Answer:

  • In mitosis one parent cell divides into two identical daughter cells, each with a nucleus having the same amount of DNA, same number of chromosomes and genes as the parent cells. It is therefore called an equational division.
  • Meiosis is called reduction division because the chromosome number is reduced to haploid (n) from diploid (2n) in the daughter cells.

Question 10.
What is terminalization?
Answer:
In the stage of diplotene of meiotic prophase I, chiasmata begin to move along the length of the chromosome from the centromere towards the end resulting in terminalization.

 Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues

Question 11.
What is a tetrad?
Answer:
The chromosomes are visible as long paired twisted threads. The pairs so formed are called bivalents. Each bivalent now contains four chromatids (tetrad stage) in pachytene of mieotic prophase I. The condition of bivalent containing four chromatids are called tetrad stage.

Question 12.
What is crossing over?
During pachytene of mieotic prophase I, the chromatids break and the broken segments are interchanged between homologous chromosomes. The points of exchange are the chiasmata. This is called .crossing over.

Question 13.
What is bouquet stage?
Answer:
During leptotene of mieotic prophase I, the chromosomes become uncoiled and assume long thread-like structures and take up a specific orientation inside the nucleus. They form a bouquet stage.

 Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues

Question 14.
What is zygotene?
Answer:
It is one of the stages of mieoticphophase I. Two homologous chromosomes approach each other and begin to pair. The pairing of homologous chromosomes is called synapsis.

Question 15.
Explain amitosis.
Answer:
It is the simplest model of cell division and occurs in unicellular animals, aging cells and in foetal membranes. During amitosis, the nucleus elongates first, and a constriction appears in it which deepens and divides the nucleus into two, followed by this cytoplasm divides resulting in the formation of two daughter cells.

Question 16.
Write the salient features of the compound epithelium.
Answer:

  • It consists of more than one layer of cells and gives a stratified appearance. Hence, they are also known as stratified epithelial cells.
  • The main function of this epithelium is to give protection to the underlying tissues against mechanical and chemical stress.
  • They also cover the dry surface of the skin, the moist surface of the buccal cavity, and the pharynx.

 Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues

Question 17.
Write a note the significance of mitosis.
Answer:

  • This equational division results in the production of diploid daughter cells (2n) with equal distribution of genetic material (DNA).
  • In multicellular organisms growth, organ development and an increase in body size are accomplished through the process of mitosis.
  • Mitosis helps in the repair of damaged and wounded tissues by the renewal of the lost cells.

Question 18.
Draw a neuron and label the parts.
Answer:
Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues 5

VII. Answer in detail:

Question 1.
What are meristems? Describe the distribution and functions of various types of meristems.
Answer:
Meristematic tissues are group of immature cells that are capable of undergoing cell division. In plants, the meristem is found in zones where growth can take place. Example: apex of stem, root, leaf primordia, vascular cambium, cork cambium, etc.,

Types of Meristems based on position:
On the basis of their position in the plant, meristems are of three types: Apical meristem, Intercalary meristem, and Lateral meristem.

Apical meristem: These are found at the apices or growing points of root and shoot and bring about an increase in length.

Intercalary meristem: It lies between the region of permanent tissues and is part of the primary meristem. It is found either at the base of leaf e.g. pinus or at the base of internodes e.g. grasses.

Lateral Meristem: These are arranged parallel and causes the thickness of the plant part.

Functions: Meristems are actively dividing tissues of the plant, that are responsible for primary (elongation) and secondary (thickness) growth of the plant.
Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues 6

Question 2.
Give one reason for the following:
a. Blood is fluid connective tissue.
b. Skeletal muscles are voluntary muscles.
c. Heart muscles are involuntary in nature.
Answer:
The blood and the lymph are the fluid connective tissues which link different parts of the body. The cells of the connective tissue are loosely spaced and are embedded in an intercellular matrix.

(a) Blood: Blood contains corpuscles which are red blood cells (erythrocytes), white blood cells (leucocytes), and platelets. In this fluid connective tissue, blood cells move in a fluid matrix called plasma. The plasma contains inorganic salts and
organic substances. It is a main circulating fluid that helps in the transport of nutrient substances.

(b) They work under our control and are also known as voluntary muscles. They are not under the control of our will and so are called involuntary muscles.

(c) Cardiac muscle: It is a special contractile tissue present in the heart. The muscle fibers are cylindrical, branched, and uninucleate The branches join to form a network called as itercalated disc which are unique distinguishing features of the
cardiac muscles. The contraction of cardiac muscle is involuntary and rhythmic.

 Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues

Question 3.
Explain simple epithelium and its types.
Answer:
Simple Epithelium :
1. It is formed of a single layer of cells. It forms a lining for the body cavities and ducts.
2. Simple epithelium is further divided into the following types.

  • Squamous epithelium
  • Cuboidal epithelium
  • Columnar epithelium
  • Ciliated epithelium
  • Glandular epithelium

(i) Squamous epithelium :

  • It is made up of thin, flat cells with prominent nuclei. These cells have irregular boundaries and bind with neighbouring cells.
  • The squamous epithelium is also known as pavement membrane, which forms the delicate lining of the buccal cavity, alveoli of lungs, proximal tubule of kidneys, blood vessels etc.
  • It protects the body from mechanical injury, drying and invasion of germs.
    Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues 7

(ii) Cuboidal epithelium:

  • It is composed of single layer of cubical cells.
  • The nucleus is round and lies in the centre.
  • This tissue is present in the thyroid vesicles, salivary glands, sweat glands, exocrine pancreas.
  • It is also found in the intestine and tubular part of the nephron (kidney tubules) as microvilli that increase the absorptive surface area.
  • Their main function is secretion and absorption.
    Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues 8

(iii) Columnar epithelium:

  • It is composed of a single layer of slender, elongated and pillar like cells.
  • Their nuclei are located at the base.
  • It is found lining the stomach, gall bladder, bile duct, small intestine, colon, oviducts and forms a mucous membrane. ‘
  • They are mainly involved in secretion and absorption.
    Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues 9

(iv) Ciliated epithelium :

  • Certain columnar cells bear numerous delicate hair like out growths called ilia and are called ciliated epithelium.
  • Their function is to move particles or mucus in a specific direction over the epithelium.
  • It is seen in the trachea of wind-pipe, bronchioles of respiratory tract, kidney tubules and fallopian tubes of oviducts.
    Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues 10

(v) Glandular epithelium :

  • Epithelial cells are often modified to form specialized gland cells which secrete chemical substances at the epithelial surface.
  • This lines the gastric glands, pancreatic tubules and intestinal glands.
    Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues 11

Question 4.
Explain the components of phloem tissue.
Answer:
Phloem is a complex tissue and consists of the following elements :
(i) Sieve elements
(ii) Companion cells
(iii) Phloem fibres
(iv) Phloem parenchyma

(i) Sieve elements :

  • The conducting elements of phloem are collectively called as Sieve elements.
  • Sieve tubes are elongated, tube-like slender cells placed end to end. The transverse walls at the ends are perforated and are known as sieve plates.
  • The main function of sieve tubes is translocation of food, from leaves to the storage organs of the plants.

(ii) Companion cells : These are elongated cells attached to the lateral wall of the sieve tubes. A companion cell may be equal in length to the accompanying sieve tube element or the mother cell may be divided transversely forming a series of companion cells.

(iii) Phloem parenchyma : The phloem parenchyma are living cells which have cytoplasm and nucleus. Their function is to store food materials.

(iv) Phloem fibers : Sclerenchymatous cells associated with primary and secondary phloem are commonly called phloem fibers. These cells are elongated, lignified and provide mechanical strength to the plant body.

 Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues

Question 5.
Write a note on blood and its components.
Answer:
Blood is a fluid connective tissue.
Blood contains corpuscles which are red blood cells (erythrocytes), white blood cells (leucocytes) and platelets. In this fluid connective tissue, the blood cells move in a fluid matrix called. The plasma contains inorganic salts and organic substances. It is a main circulating fluid that helps in the transport of nutrient substances.

Red blood corpuscles (Erythrocytes):

  • The red blood corpuscles are oval shaped, circular, biconcave disc-like and lack nucleus when mature (mammalian RBC).
  • They contain a respiratory pigment called haemoglobin which is involved in the transport of oxygen to tissues.

White blood corpuscles (Leucocytes): They are larger in size, contain distinct nucleus and are colourless. They are capable of amoeboid movement and play an important ‘ role in body’s defense mechanism. WBC’s are of two types :
(i) Granulocytes.
(ii) Agranulocytes.

(i) Granulocytes have irregular shaped nuclei and cytoplasmic granules. They include the neutrophils, basophils and eosinophils. Agranulocytes lack cytoplasmic granules and include the lymphocytes and monocytes.

Blood platelets : They are minute, anucleated, fragile fragments of giant bone marrow called mega karyocytes They play an important role in blood clotting mechanism.
Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues 12

VIII. Higher Order Thinking Skills :

Question 1.
Identify the figure given below
Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues 13
(a) Label the parts A, B and C.
(b) What is the chemical composition of the tissue?
Answer:
(a) T.S. of Bone
(A) Lamellae
(B) Lacunae
(C) Central (Haversian canal)
(b) The matrix of the bone is rich in calcium salts and collagen fibres which gives the bone its strength.
(c) C – Haversian canal

 Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues

Question 2.
Identify figures A and B.
Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues 14
(a) …………… epithelium forms the outer lining of the buccal cavity.
(b) ………………. epithelium consist of ceils that are tall and pillar-like.
(c) Which one allows diffusion of substances?
(d) Which is called pavement epithelium?
(e) Which epithelium lines the gastrointestinal tract and epiglottis?
Answer:
Figure A – Squamous Epithelium
Figure B. – Glandular epithelium
(a) Squamous
(b) Columnar
(c) Columnar epithelium
(d) Squamous epithelium
(e) Columnar epithelium

Question 3.
If cell (A) has undergone one mitotic division and another cell (B) has completed its meiotic division. The number of cells produced in A and B would be
Cell A: Cell B :
Answer:
Cell A : 2 daughter cells.
Cell B : 4 daughter cells.

Question 4.
Identify the stage of mitosis from the below picture. List the chromosomal events in this stage.
Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues 15

Answer:
Mitotic anaphase
(i) The centromeres attaching the two chromatids divide and the two daughter chromatids of each chromosome separate and migrate towards the two opposite poles.
(ii) The migration of the daughter chromosomes is achieved by the contraction of spindle fibres.

 Samacheer Kalvi 9th Science Guide Chapter 18 Organization of Tissues

Question 5.
Identify the following relationship
Cuboidal : Epithelial
Cardiac : ………..
Granulocytes : …………
Osteocytes : ………….
Answer:
Cardiac : Muscular
Granulocytes : Blood cells
Osteocytes : Bone cells

Question 6.
Umbilical cord blood is collected at the time of child birth and stored in stem cell banks? Reason out.
Answer:

  • Umbilical cord blood consists of stem cells, they are undifferentiated cells which undergo unlimited divisions and give rise to one or more different types of cells. – Embryonic stem cells differentiate into different tissues and organs.
  • Stem cells can be used in the treatment of certain degenerative diseases in future.

Question 7.
How do WBC help in defence?
Answer:
They are capable of amoeboid movement and play an important role. They engulf or destroy foreign bodies.

Samacheer Kalvi 9th Science Guide Chapter 19 Plant Physiology

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9th Science Guide Plant Physiology Text Book Back Questions and Answers

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

I. Choose the correct answer :

Question 1.
The tropic movement that helps the climbing vines to find a suitable support is …………….
(a) phototropism
(c) thigmotropism
(b) geotropism
(d) chemotropism
Answer:
(c) thigmotropism

Question 2.
The chemical reaction occurs during photosynthesis is .
(a) CO2 is reduced and water is oxidized
(b) water is reduced and CO2 is oxidized
(c) both CO2 and water are oxidized
(d) both CO2 and water are produced
Answer:
(a) CO2 is reduced and water is oxidized

Question 3.
The bending of root of a plant in response to water is called …………………….
(a) Thigmonasty
(b) Phototropism
(c) Hydrotropism
(d) Photonasty
Answer:
(c) Hydrotropism

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

Question 4.
A growing seedling is kept in the dark room. A burning candle is placed near it for a few days. The tip part of the seedling bends towards the burning candle. This is an example of ……………
(a) Chemotropism
(b) Geotropism
(c) Phototropism
(d) Thigmotropism
Answer:
(c) Phototropism

Question 5.
The root of the plant is …………………
i) positively phototropic but-negatively geotropic
ii) positively geotropic but negatively phototropic
iii) negatively phototropic but positively hydrotropic
iv) negatively hydrotropic but.positively phototropic
(a) (i) and (ii)
(b) (ii) and (iii)
(c) (iii) and (iv)
(d) (i) and (iv)
Answer:
(b) (ii) and (iii)

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

Question 6.
The non-directional movement of a plant part in response to temperature is called………………..
(a) Thermotropism
(b) Thermonasty
(c) Chemotropism
(d) Thigmonasty
Answer:
(b) Thermonasty

Question 7.
Chlorophyllin a leaf is required for …………………
(a) photosynthesis
(b) tropic movement
(c) transpiration
(d) nastic movement
Answer:
(a) photosynthesis

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

Question 8.
Transpiration takes place through ………………..
(a) fruit
(b) seed
(c) flower
(d) stomata
Answer:
(d) stomata

II. Fill in the blanks :

1. The shoot system grows upward in response to ………………..
Answer:
light

2. ………………..is positively hydrotropic as well as positively geotropic.
Answer:
root

3. The green pigment present in the plant is………………..
Answer:
chlorophyll

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

4. The solar tracking of sunflower in accordance with the path of sun is due to …………………
Answer:
phototropism:

5. The response of a plant part towards gravity is ………………..
Answer:
geotropism

6. Plants take in carbon dioxide for photosynthesis but need ……………….. for their living.
Answer:
oxygen

III. Match column A with column B

Column A

Column B

1. Roots growing downwards into soil. Positive phototropism
2. Shoots growing towards the light. Negative geotropism
3. Shoots growing upward. Negative phototropism
4. Roots growing downwards away from light. Positive geotropism

Answer:

Column A Column B
1. Roots growing downwards into soil. Positive geotropism
2. Shoots growing towards the light. Positive phototropism
3. Shoots growing upward. Negative geotropism
4. Roots growing downwards away from light. Negative phototropism

IV. State whether true or false. If false, correct the statement:

1. The response of a part of plant to the chemical stimulus is called phototropism.
Answer:
False.
Correct statement : The response of a plant part to the chemical stimulus is called Itemoiropisin.

2. Shoot is positively phototropic and negatively geotropic.
Answer:
True.

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

3. When the weather is hot, water evaporates lesser which is due to opening of stomata.
Answer:
False.
Correct statement: When the weather is hot, water evaporates more but stomata begin to close to reduce evaporation.

4. Photosynthesis produces glucose and carbon dioxide.
Answer:
False.
Correct statement: Photosynthesis produces glucose and oxygen.

5. Photosynthesis is important in releasing oxygen to keep the atmosphere in balance.
Answer:
True

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

6. Plants lose water when the stomata on leaves are closed.
Answer:
False.
Correct statement: Plants lose water when the stomata on leaves are open.

V. Answer very briefly :

Question 1.
What is nastic movement?
Answer:
Non-directional response to the stimulus is called Nastic movements.

Question 2.
Name the plant part
a) Which bends in the direction of gravity but away from the light.
b) Which bends towards the light but away from the force of gravity.
Answer:
a) Root system
b) Shoot system.

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

Question 3.
Differentiate phototropism from photo nasty.
Answer:
Phototropism:

  1. Movement of a plant part towards the light.
  2. Eg: Shoot of a plant.

Photonasty:

  1. Movement of a plant part is a response to light.
  2. Eg: Moonflower, Taraxacum Officinale.

Question 4.
Photosynthesis converts energy X into energy Y.
a) What are X and Y?
b) Green plants are autotrophic in their mode of nutrition. Why?
Answer:
a) X → light energy,
Y → Chemical energy.
b) Green plants are autotrophic in their mode of nutrition because they prepare then- own food materials through photosynthesis.

Question 5.
Define transpiration.
Answer:
The loss of water in the form of water vapour from the aerial parts of the plant body is called Transpiration.

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

Question 6.
Name the cell that surrounds the stoma.
Answer:
Each stomata is surrounded by guard cells.

VI. Answer briefly :

Question 1.
Give the technical terms for the following :
a) Growth dependent movement in plants.
b) Growth independent movement in plants.
Answer:
a) Tropic movements
b) Nastic movements

Question 2.
Explain the movement seen in Pneumatophores of Avicennia.
Answer:

  • Pneumato[hores are specialized roots that can involve in the respiration of plants,
  • This type of roots intakes the gas through its lenticel. a small hole in their both.

Question 3.
Fill in the blanks:
Samacheer Kalvi 9th Science Guide Chapter 19 Plant Physiology 1
Answer:
Samacheer Kalvi 9th Science Guide Chapter 19 Plant Physiology 2

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

Question 4.
What is chlorophyll?
Answer:
Chlorophyll is a green pigment present in all green plants with is responsible for the absorption of light to provide energy for photosynthesis.

Question 5.
Name the part of plant which shows positive geotropism. Why?
Answer:
Root shows positive geotropism because of the unidirectional movement in response to gravity.

Question 6.
What is the difference between the movement of flowers in the sunflower plant and the closing of the leaves in the Mimosa pudica?
Answer:
Movement of flower in sunflower plant:
In sunflower plant the stem tip follows the path of the sun from dawn to dusk (East to est) and in night it moves from West to East. This is a growth movement and takes place in response to the stimulus ‘light’. It is an example of tropic movement in response to light and is called phototropism.

Closing of the leaves in the Mimosa pudica :
The closing of leaves in Mimosa pudica occurs in response to touch. It is not a growth movement and occurs independently of the direction of stimulus. This is nastic movement . and is called Thigmonasty.

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

Question 7.
Suppose you have a rose plant growing in a pot, how will you demonstrate transpiration in it?
Answer:
Tie a plastic bag over leaves of rose plant and place in sunlight. After a few hours, we see water condensing inside the plastic bag. This is due to loss of water in the form of water vapour, which condenses into water. This is due to transpiration.

Question 8.
Mention the differences between stomatal and lenticular transpiration.
Answer:
Stomatal transpiration :

  1. Loss of water from plants through stomata.
  2. 90-95% of transpiration in a plant takes place through stomata only.

Lenticular transpiration :

  1. Loss of water from plants as vapour through the lenticels.
  2. A very small percentage of water is lost by through plants lenticular transpiration.

Question 9.
To which directional stimuli do (a) roots respond (b) shoots respond?
Answer:
(a) Roots respond positively geostrophic and negatively phototrophic.
(b) Shoots respond negatively geostrophic and positively phototrophic.

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

VII. Answer in detail :

Question 1.
Differentiate between tropic and nastic movements
Answer:
Tropic movements

  1. Unidirectional response to the stimulus.
  2. Growth dependent movements.
  3. More or less permanent and irreversible.
  4. Found in all plants.
  5. Slow action.

Nastic movements :

  1. Non-directional response to the stimulus
  2. Growth independent movements. –
  3. Temporary and reversible.
  4. Found only in a few specialized plants.
  5. Immediate action.

Question 2.
How will you differentiate the different types of transpiration?
Answer:
There are three types of transpiration:
Stomatal transpiration: Loss of water from plants through stomata. It accounts for 90- 95% of the water transpired from leaves.
Cuticular transpiration: Loss of water in plants through the cuticle.
Lenticular transpiration: Loss of water from plants as vapour through the lenticels. The lenticels are tiny openings that protrude from the barks in woody stems and twigs as well as in other plant organs.
But transpiration is necessary for the following reasons.

  1. It creates a pull in leaf and stem.
  2. It creates an absorption force in roots.
  3. It is necessary for a continuous supply of minerals.
  4. It regulates the temperature of the plant.

VIII. Higher Order Thinking Skills:

Question 1.
There are 3 plants A, B and C. The flowers of A open their petals in bright light during the day but closes when it gets dark at night. On the other hand, the flowers f of plant B open their petals at night but closes during the day when there is a bright light. The leaves of plant C fold up and droop when touched with fingers or any other solid object.
(a) Name the phenomenon shown by the flowers of plants A and B.
(b) Name one plant each which behaves like the flowers of plant A and B.
(c) Name the phenomenon exhibited by the leaves of plant C.
Answer:
(a) Photonasty
(b) Plant A – Common Dandelion – Taraxacum officinale
Plant B – Moonflower – Ipomoea alba
(c) Nyctinasty

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

Question 2.
Imagine that student A studied the importance of certain factors in photosynthesis.
He took a potted plant and kept it in dark for 24 hours. In the early hours of the next
morning, he covered one of the leaves with dark paper in the centre only. Then he placed the plant in sunlight for a few hours and tested the leaf which was covered
with black paper for starch.
(a) What aspect of photosynthesis was being investigated?
(b) Why was the plant kept in the dark before the experiment?
(c) How will you prove that starch is present in the leaves?
Answer:
(a) Necessity of light as a factor for Photosynthesis.
(b) To make the plant starch-free before starting the experiment. After the experiment, if starch is found in the leaf it will be the starch prepared by leaves during the experiment only.
(c) Presence of starch in the leaves can be proved by doing the starch test.

  • The potted plant is kept in bright sunlight for 4 to 6 hours.
  • The selected covered leaf is plucked and the black paper is removed.
  • The leaf is immersed in boiling water for a few minutes and then in alcohol to remove chlorophyll.
  • The leaf is now tested with iodine solution for the presence of starch.
  • The covered part of the leaf does not turn blue-black whereas the uncovered part of the leaf turns blue-black colour.
  • The covered part of the leaf which did not receive the sunlight was unable to synthesize starch.
  • Hence it does not turn blue-black colour.
  • But the uncovered part of the leaf which received sunlight was able to synthesize starch and so it turns blue-black in colour.

Intext Activities

ACTIVITY – 1

Take a glass trough and fill it with sand. Keep a flower pot containing water, plugged at the bottom at the centre of the glass trough. Place some soaked pea or bean seeds around the pot in the sand. What do you observe after 6 or 7 days? Record your observation.

Aim : To demonstrate hydrotropism.
Materials required : Glass trough, sand, flower pot, plugged at the bottom, pea or bean seeds and water.

Samacheer Kalvi 9th Science Guide Chapter 19 Plant Physiology 3

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

Procedure :

  1. A glass trough is taken and is filled with sand. A flowerpot containing water plugged at the bottom is kept at the centre of the glass trough.
  2. Soaked pea or bean seeds are placed around the pot in the sand. It is observed after 6 or 7 days.

Observation: Observed that radicle has grown towards the pot and moisture instead of growing vertically downward.
Inference: It proves that primary root is positively hydrotropic.
Result: Hydrotropism has been demonstrated by showing positive hydrotropism in roots.

[End of the activity]

ACTIVITY – 2

Take pea seeds soaked in water overnight. Wait for the pea seeds to germinate. Once the seedling has grown put it in a box with an opening for light on one side. After few hours, you can clearly see how the stem has bent and grown towards the light.

Aim : To demonstrate phototropism.
Materials required : Box, water, light and pea seeds.

Procedure:

  1. Take pea seeds soaked in water overnight. Wait for the pea seeds to germinate.
  2. Once the seedling has grown put it in a box with an opening for light on one side.
  3. After few hours, you can clearly see how the stem has bent and grown towards the light.

Observation : Observed that movement of a stem of a plant (pea seeds) towards light moist condition. This is the way a new plant develops from a seed.
Inference : Positive phototropism of a plant has been demonstrated.

[End of the activity]

ACTIVITY – 3

Pluck a variegated leaf from Coleus plant kept in sunlight. De- starch it by keeping in dark room for 24 hours. Draw the picture of this leaf and mark the patches of cholorphyll on the leaf. Immerse the leaf in boiling water followed by alcohol and test it for starch using iodine solution. Record your observation.

Aim : To show that chlorophyll is essential for photosynthesis.
Materials required : Plant with variegated leaves, boiling water, alcohol and iodine solution.
Samacheer Kalvi 9th Science Guide Chapter 19 Plant Physiology 4

Procedure:
Variegated leaf is plucked from Coleus plant kept in sunlight. It isde-starched by keeping it in dark room for 24 hours. The picture of this leaf is drawn and the patches of cholorphyll on the leaf are marked. After immersing the leaf in boiling water followed by alcohol it is tested for starch with iodine solution.

Observation : The patches of the leaf with chlorophyll turn blue-black. The other portions remain colourless.
Inference: The chlorophyll is essential for photosynthesis.

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

ACTIVITY – 4

Place a potted plant in a dark room for about 2 days to de-starch its leaves. Cover one of its leaves with the thin strip of black paper as shown in the picture, make sure that the leaf is covered on both sides. Keep the potted plant in bright sunlight for 4 to 6 hours. Pluck the selected covered leaf and remove the black paper.
Immerse the leaf in boiling water for a few minutes and then in alcohol to remove chlorophyll. Test the leaf now with iodine solution for the presence of starch. The covered part of the leaf does not turn blue-black whereas the uncovered part of the leaf turns blue-black colour. Why are the changes in colour noted in the covered and uncovered part of the leaf?
Samacheer Kalvi 9th Science Guide Chapter 19 Plant Physiology 5

Aim : To show that light is essential for photosynthesis.
Materials required : Covered leaf, boiling water, alcohol and iodine.

Procedure:

  1. A potted plant is placed in a dark room for about 2 days to de-starch its leaves.
  2. One of its leaves is covered with a thin strip of black paper as shown in the picture.
  3. Make sure that the leaf is covered on both sides.
  4. The potted plant is kept in bright sunlight for 4 to 6 hours.
  5. The selected covered leaf is plucked and the black paper is removed.
  6. Th e leaf is immersed in boiling water for a few minutes and then in alcohol to remove chlorophyll.
  7. The leaf is now tested with iodine solution for the presence of starch.

Observation : The covered part of the leaf does not turn blue-black whereas the uncovered part of the leaf turns blue black colour. The covered part of the leaf which did not receive sunlight was unable to synthesize starch.
Inference : The light is essential for photosynthesis.

9th Science Guide Plant Physiology in Animals Additional Important Questions and Answers

I. Choose the correct answer :

Question 1.
The bending of root of a plant in response to water is called …………………..
(a) thigmonasty
(b) phototropism
(c) hydrotropism
(d) photonasty
Answer:
(c) hydrotropism

Question 2.
A growing seedling is kept in the dark room. A burning candle is placed near it for a few days. The top part of the seedling bends towards the burning candle. This is an example of ……………………
(a) chemotropism
(b) thigmotropism
(c) phototropism
(d) geotropism
Answer:
(c) phototropism

Question 3.
The root of the plant is ……………………
(i) positively phototropic but negatively geotropic.
(ii) positively geotropic but negatively phototropic.
(iii) negatively phototropic but positively hydrotropic.
(iv) negatively hydrotropic but positively phototropic.
(a) (i) and (ii)
(b) (ii) and (iii)
(c) (iii) and (iv)
(d) (i) and (iv)
Answer:
(b) (ii) and (iii)

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

Question 4.
The plant part which exhibits negative geotropism is ……………………
(a) root
(b) stem
(c) branch
(d) leaves
Answer:
(b) stem

Question 5.
The non-directional movement of a plant part in response to temperature is called…………………..
(a) thermotropism
(b) thermonasty
(c) chemotropism
(d) thigmonasty
Answer:
(b) thermonasty

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

Question 6.
Sunflowers open the petals in bright light during the day time but close the petals in dark at night. This response of sunflowers is called ……………………
(a) geonasty
(b) thigmonasty
(c) chemonasty
(d) photonasty
Answer:
(d) photonasty

Question 7.
During photosynthesis plants exhale ……………………
(a) Carbon dioxide
(b) oxygen
(c) hydrogen
(d) helium
Answer:
(b) oxygen

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

Question 8.
Chlorophyll in a leaf is required for ……………………
(a) photosynthesis
(b) transpiration
(c) tropic movement
(d) nastic movement
Answer:
(a) photosynthesis

Question 9.
A plant is kept in a dark room for about 24 hours before conducting any experiment on photosynthesis in order to ……………………
(a) remove chlorophyll from the leaf
(b) remove starch from the leaves
(c) ensure that photosynthesis occurred
(d) to prove transpiration
Answer:
(b) remove starch from the leaves

Question 10.
Transpiration takes place through ……………………
(a) fruit
(b) seed
(c) flower
(d) stomata
Answer:
(d) stomata

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

Question 11.
Thigmonasty can be seen in ……………………
(a) Mimosa pudica
(b) Taraxacum officinale
(c) Ipomea alba
(d) Rhizophora
Answer:
(a) Mimosa pudica

Question 12.
The venus flytrap plants are examples for …………………..
(a) chemotropism
(b) thigmonasty
(c) hydrotropism
(d) thigmotropism
Answer:
(b) thigmonasty

Question 13.
………………….. flowers bloom as the temperature increases.
(a) Rose
(b) Jasmine
(c) Lilly
(d) Tulip
Answer:
(d) Tulip

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

Question 14.
Only green plants have the unique capacity to release ………………….. into the atmosphere.
(a) nitrogen
(b) oxygen
(c) carbon dioxide
(d) ozone
Answer:
(b) oxygen

Question 15.
The end product of photosynthesis is ……………………
(a) glucose
(b) sucrose
(c) fructose
(d) none of the above
Answer:
(a) glucose

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

II. Fill in the blanks :

1. The minerals like nitrogen, potassium and phosphorus, are required in substantial quantity by the plants are called …………………..
Answer:
macronutrients

2. The solar tracking of sunflower in accordance with the path of sun is due to ………………………
Answer:
phototropism

3. The response of a plant part towards gravity is ………………………
Answer:
geotropism

4. When the leaves of a sensitive plant are touched with a finger, they fold up and when light fades at dusk the petals of a sunflower. These two plants show ……………………..and ……………………..movements.
Answer:
thigmonastic, photonastic

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

5. Opening and closing of Moon flower is not a tropism because the movement in this is……………………..
Answer:
independent of stimulus

6. The raw materials for photosynthesis are …………………….. and ………………………
Answer:
carbon dioxide, water

7. When iodine solution is added for testing starch, part of the leaf with …………………….. turn blue- black colour.
Answer:
starch

8. In leaves, the food is stored in the form of……………………..
Answer:
starch

9. Plants may inhale carbon dioxide for photosynthesis but need ……………………..for their living.
Answer:
oxygen

10. Plants utilize only ……………………..% of the absorbed water for photosynthesis and the other activities.
Answer:
1

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

11 . Plants inhale and exhale continuously through the . ……………………..
Answer:
stamata

12. The bending of shoot towards light is due to the hormone ……………………..
Answer:
auxin

13. Heliotropism is a kind of ……………………..
Answer:
phototropism

14. The ……………………..plant exhibits one of the fastest known nastic movements.
Answer:
venus flytrap

15. Chlorophyll differs from haemoglobin by the presence of its central molecule ……………………..
Answer:
magnesium

16. Plants exchange gases ……………………..continuously through these stomata.
Answer:
CO2 to O2

17. Guard cells help in regulating the ……………………..
Answer:
rate of transpiration

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

III. Analogy :

Question 1.
Towards a stimulus : ……………….:: Away from the stimulus : Negative tropism
Answer:
Positive tropism

Question 2.
Hydrotropism : Response towards water :: Phototropism : …………..
Answer:
Response towards light

Question 3.
Photosynthesis : ……………….. :: Transpiration : Stomata
Answer:
Green leaves

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

IV. State whether the following statements are true or false. If false, write the correct statement :

1. Scientific term used to represent the bending of roots towards water is called geotropism.
Answer:
False.
Correct statement: Scientific term used to represent the bending of roots towards water is called hydrotropism.

2. When the leaves of Mimosa pudica plant are touched with the finger, they fold up quickly.
Answer:
True.
Correct statement: This is an example of thigmonasty.

3. The petals of moon flower open up in morning and closes in the evening. This is called photonasty.
Answer:
False.
Correct statement :The petals of moon flower dost ‘ in the morning and opens up in the evening. This is called photonasty.

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

4. Photosynthesis produces glucose and carbon dioxide.
Answer:
False.
Correct statement: Photosynthesis produces glucose and oxygen.

5. Photosynthesis is important in releasing oxygen to keep the atmosphere in balance.
Answer:
True.

6. Plants lose water when the stomata on leaves are closed.
Answer:
False.
Correct statement: Plants will not lose water when the stomata on leaves are closed.

V. Assertion and reason :

Question 1.
Assertion (A) : If the plant part moves in the direction of gravity, it is called positive geotropism.
Reason (R) : Stem shows positive geotropism.
(a) A and R are incorrect
(b) A is incorrect, R is correct
(c) A is correct, R is incorrect
(d) Both A and R are correct
Answer:
(c) A is correct, R is incorrect

Question 2.
Assertion (A) : The loss of excess water from the aerial parts of the plant in the form of water vapour is known as transpiration.
Reason (R) : Stomata of the leaf perform transpiration.
(a) A and R are incorrect
(b) A is incorrect, R is correct
(c) A is correct, R is incorrect
(d) Both A and R are correct
Answer:
(d) Both A and R are correct

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

VI. Short answer questions :

Question 1.
Write the scientific terms used to represent the following:
(a) Growing of roots towards the gravity.
(b) Bending of roots towards the water.
Samacheer Kalvi 9th Science Guide Chapter 19 Plant Physiology 6
Answer:
(a) Positive geotropism
(b) Positive hydrotropism.

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

Question 2.
Observe the given picture.
(a) Identify this plant. What type of special movement is shown by this plant?
(b) What are the other movements seen in this plant?
Answer:
(a) Mimosa pudica.
Special movement shown by the plant: Just a casual touch is enough to make the leaves of Mimosa pudica (Touch-me- not plant) fold up and droop. This is described as seismonasty or thigmonasty.
Movements which are not directed towards stimuli but are independent of the stimulus direction are called as nastie movements. They may or may not be growth movement.

(b) The foliage of Mimosa closes during darkness and reopens in the presence of light. Note : The ‘rapid movement of in leaflets in Mimosa is rare in the plant kingdom and is related to changes in turgor pressure.

Question 3.
What is the end product of photosynthesis?
Answer:
The end product of photosynthesis is glucose which is converted into starch and stored in the plant parts.

Question 4.
Name the minute openings seen on the lower surface of the leaf.
Answer:
Stomata are the minute openings seen on the lower surface of the leaf.

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

Question 5.
Give the scientific terms for the following:
(a) Growth dependent movement in plants.
(b) Growth independent movement in plants.
Answer:
(a) Tropic movements
(b) Nastie movements.

Question 6.
Study the pictures below and then complete the table by putting a plus (+) if the shoot or root grows towards the stimulus and a minus (-) if it grows away from it.
Samacheer Kalvi 9th Science Guide Chapter 19 Plant Physiology 7
Samacheer Kalvi 9th Science Guide Chapter 19 Plant Physiology 8
Answer:
Samacheer Kalvi 9th Science Guide Chapter 19 Plant Physiology 9

Question 7.
What is the other name for thigmonasty?
Answer:
Seismonasty.

Question 8.
Which flowering plant shows photonasty just opposite to that of Dandelion?
Answer:
Moon flower.

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

Question 9.
Give an example for negative hydrotropism.
Answer:
Growth of certain fungal hyphae away from the source of water/moisture.
Note : No clear evidences of negative hydrotropism.

Question 10.
Which gas is evolved during photosynthesis?
Answer:
Oxygen.

Question 11.
Give an example for micronutrients.
Answer:
Zinc.

Question 12.
What does a Mimosapudica plant do in response to touch? What is the phenomenon known as?
Answer:
In response to touch, the leaves of the plant Mimosa pudica fold up and droop. The movement is known as seismonasty or thigmonasty.

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

Question 13,
(i) What happens to the dandelion flower
(a) During the daytime?
(b) At night?
(ii) What is the phenomenon known as?
Answer:
(i) (a) The dandelion flower unfolds.
(b) The dandelion flower closes.
(ii) The phenomenon is known as photonasty.

Question 14.
Define photosynthesis.
Answer:
‘Photo’ means Tight’ and ‘synthesis’ means ‘to build’ thus photosynthesis literally means ‘building up with the help of light’. During this process, the light energy is converted into chemical energy. Green plants are autotrophic in their mode of nutrition because they prepare their food materials through a process called photosynthesis.\

Question 15.
Draw the structure of stomata and label the parts.
Answer:
Samacheer Kalvi 9th Science Guide Chapter 19 Plant Physiology 10

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

Question 16.
Complete the following table with the different types of tropism:
Samacheer Kalvi 9th Science Guide Chapter 19 Plant Physiology 11
Answer:
Samacheer Kalvi 9th Science Guide Chapter 19 Plant Physiology 12

Question 17.
Label the diagram with the raw materials and products of photosynthesis.
Samacheer Kalvi 9th Science Guide Chapter 19 Plant Physiology 13
Answer:
A. Carbon dioxide
B. Water
C. Glucose
D. Oxygen

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

Question 18.
Give an example for the movement of plant part which is very quick and can be observed easily.
Answer:
Just a casual touch is enough to make the leaves of Mimosa pudica fold up and droop. This takes place quickly and can be easily observed.

Question 19.
Name the cell that surrounds the stoma.
Answer:
Guard cells.

Question 20.
Give an example for chemotropism.
Answer:
During fertilization, pollen tube grows down the style in response to the sugars in the style is an example of chemotropism.

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

Question 21.
Give the overall equation for photosynthesis.
Answer:
Samacheer Kalvi 9th Science Guide Chapter 19 Plant Physiology 14

Question 22.
Guard cells of stomata are green but cannot photosynthesize? Give reason.
Answer:
The enzymes needed for photosynthetic reactions are absent and hence guard cells cannot photosynthesize. _ .

Question 23.
Why do roots of halophytes show negative geotropism.
Answer:
The roots turn 180° upright for respiration.

Question 24.
Why do stems show postive phototropism?
Answer:

  • Stem growing up and towards light is more likely to get sunlight for photosynthesis and display its flowers prominently for pollinators to arrive.
  • It also has better chance of spreading its seeds.

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

Question 25.
Mention four factors required for photosynthesis?
Answer:
Chlorophyll, Water, Carbon dioxide and Light.

Question 26.
Why is transpiration called as necessary evil?
Answer:
Water is lost by transpiration but still it is a necessary process since it gives the following advantages to the plant.

  • Creates an absorption force in roots to suck more water form the soil.
  • Regulates the temperature of the plant. Hence transpiration is said to be a necessary evil.

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

Question 27.
What are stomata?
Answer:
The leaves have tiny holes, t ailed slomaia, through which the exchange of air takes place. The leaves have tiny, microscopic pores called stomata. Water evaporates through these stomata. Each stomata is surrounded by guard cells. These guard cells help in regulating the rate of transpiration by opening and closing of stomata.

Question 28.
Write the scientific terms used to represent.
Answer:
Leaves fold up and droop in touch-me-not plant Mimosa pudica Ans. Thigmonasty or Seismonasty.
Example: Brunnichia ovata and Mimosa pudica.

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

VII. Long answer questions :

Question 1.
Write a note on Transpiration.
Answer:

  • The loss of water in the form of wate r vapour from the aerial parts of the plant body is called as transpiration.
  • The leaves have tiny, microscopic pores called stomata.
  • Water evaporates through these stomata. Each stomata is surrounded by guard cells.
  • These guard cells help in regulating the rate of transpiration by opening and closing of stomata.

Question 2.
Write the types of tropism.
Answer:
Types of Tropism :
Based on the nature of stimuli, tropism can be classifi ed as follows.
Phototropism : Movement of a plant part towards light, e.g. shoot of a plant.
Geotropism : Movement of a plant in response to gravity, e.g. root of a plant.
Hydrotropism : Movement of a plant or part of a plant towards water, e.g root of a plant.
Thigmotropism : Movement of a plant part due to touch, e.g. climbing vines.
Chemotropism : Movement of a part of plant in response to chemicals, e.g growth of a pollen tube in response to sugar present on the stigma.

Tropism is generally termed positive if growth is towards the signal and negative if it is away from the signal. Shoot of a plant moves towards the light, the roots move away. Th us the shoots are positively phototropic.
Samacheer Kalvi 9th Science Guide Chapter 19 Plant Physiology 15
Usually shoot system of a plant is positively phototropic and negatively geotropic and root system is negatively phototropic and positively geotropic.
Samacheer Kalvi 9th Science Guide Chapter 19 Plant Physiology 16

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

VIII. Higher Order Thinking Skills :

Question 1.
While conducting experiments to study the effects of various stimuli on the plants, it was observed that the roots of a plant X grow and bend towards two stimuli A and B but bend away from a third stimulus C. The stem of the plant X however bends ” away from stimulus A and B but bends towards the stimulus C. The stimulus B is known to act on the roots due to factors related with Earth. Keeping these points in mind, answer the following questions:
(a) What could be stimulus A ?
(b) Name the stimulus seen in B.
(c) What could be stimulus-C?
Answer:
(a) Stimulus A – Water
(b) Stimulus B – Gravity
(c) Stimulus C – Light

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

Question 2.
An organism A which cannot move from one place to another makes a simple food B from the substances C and D available in the environment. This food is made in the presence of green coloured substance E present in organs F in the presence of light energy in a process called G. Some of the simple food B also gets converted into a complex food H for storage purposes. This food gives blue-black colour with iodine solution?
(a) What is (i) organism A (ii) food B and food H?
(b) What are C and D?
(c) Name (i) green coloured substance E and organ F.
(d) What is the process G?
Answer:
(a) (i) Organism A refers to Green plants.
(ii) Food B – Glucose
Food H – Starch

(b) C – Carbon dioxide
D – Water

(c) Green coloured substance E – Chlorophyll
Organ F – Leaves

(d) G – Photosynthesis process.

Samacheer Kalvi 9th Science Guide Chapter 17 Animal Kingdom

Tamilnadu State Board New Syllabus Samacheer Kalvi 9th Science Guide Pdf Chapter 17 Animal Kingdom Text Book Back Questions and Answers, Notes.

Samacheer Kalvi 9th Science Solutions Chapter 17 Animal Kingdom

9th Science Guide Animal Kingdom Text Book Back Questions and Answers

I. Choose the correct answer :

Question 1.
Find the group having only marine members.
(a) Mollusca
(b) Coelenterata
(c) Echinodermata
(d) Porifera
Answer :
(d) Echinodermata

 Samacheer Kalvi 9th Science Guide Chapter 17 Animal Kingdom

Question 2.
Mesoglea is present in
(a) Porifera
(b) Coelenterata
(c) Annelida
(d) Arthropoda
Answer:
(b) Coelenterata

 Samacheer Kalvi 9th Science Guide Chapter 17 Animal Kingdom

Question 3.
Which one of the following pairs is not a poikilothermic animal
(a) Fishes and Amphibians
(b) Amphibians and Aves
(c) Aves and Mammals
(d) Reptiles and Mammals
Answer:
(c) Aves and Mammals

Question 4
Identify the animal having four chambered heart.
(a) Lizard
(b) Snake
(c) Crocodile
(d) Calotes
Answer:
(c) Crocodile

 Samacheer Kalvi 9th Science Guide Chapter 17 Animal Kingdom

Question 5
The animal without skull is
(a) Acrania
(b) Acephalia
(c) Apteria
(d) Acoelomate
Answer:
(a) Acrania

Question 6.
Hermaphrodite organisms are
(a) Hydra, Tape worm, Earthworm, Amphioxus
(b) Hydra, Tape worm, Earthworm, Ascidian
(c) Hydra, Tape worm, Earthworm, Balanoglossus
(d) Hydra, Tape worm, Ascaris, Earthworm
Answer:
b) Hydra, Tap worm, Earthworm, Ascidian

Question 7.
Poikilothermic organisms are
(a) Fish, Frog, Lizard, Man
(b) Fish, Frog, Lizard, Cow
(c) Fish, Frog, Lizard, Snake
(d) Fish, Frog, Lizard, Crow
Answer:
(c) Fish, Frog, Lizard, Snake

 Samacheer Kalvi 9th Science Guide Chapter 17 Animal Kingdom

Question 8.
Air sacs and Pneumatic bones are seen in
(a) fish
(b) frog
(c) bird
(d) bat
Answer:
(c) Bird

Question 9.
Excretory organ of tape worm is
(a) flame cells
(b) nephridia
(c) body surface
(d) solenocytes
Answer:
(a) Flame cells

Question 10.
Water vascular system is found in
(a) Hydra
(b) Earth worm
(c) Star fish
(d) Ascaris
Answer:
(c) Starfish

 Samacheer Kalvi 9th Science Guide Chapter 17 Animal Kingdom

II. Fill in the blanks :

1. The skeletal framework of Porifera is ……………..
Answer:
spicules

2. Ctenidia are respiratory organs in ……………….
Answer:
phylum mollusca

3. Skates are ………………. fishes.
Answer:
cartilaginous

 Samacheer Kalvi 9th Science Guide Chapter 17 Animal Kingdom

4. The larvae of an amphibian is …………………..
Answer:
bilaterally symmetrical

5. ………………. are jawless vertebrates.
Answer:
Cyclostomes

6. …………………… is the unique characteristic feature of mammal.
Answer:
Placenta

 Samacheer Kalvi 9th Science Guide Chapter 17 Animal Kingdom

7. Spiny anteater is an example for …………….. mammal.
Answer:
egg-laying

III. State whether true or false. If false write the correct statement :

1. Canal system is seen in coelenterates.
Answer:
False.
Correct statement: Canal system is seen in porifera

2. Hermaphrodite animals have both male and female sex organs.
Answer:
True,

3. Trachea are the respiratory organ of Annelida.
Answer:
False.
Correct statement: Trachea are the respiratory organ of Arthopoda.

 Samacheer Kalvi 9th Science Guide Chapter 17 Animal Kingdom

4. Bipinnaria is the larva of Mollusca.
Answer:
False.
Correct statement: Bipinnaria is the larva of star fish.

5. Balanoglossus is a ciliary feeder.
Answer:
True.

6. Fishes have two chambered heart.
Answer:
True.

 Samacheer Kalvi 9th Science Guide Chapter 17 Animal Kingdom

7. Skin of reptilians are smooth and moist.
Answer:
False.
Correct statement: Skin of cyclostomata are smooth and moist.

8. Wings of birds are the modified forelimbs.
Answer:
True

9. Female mammals have mammary glands.
Answer:
True.

 Samacheer Kalvi 9th Science Guide Chapter 17 Animal Kingdom

IV. Match the following :

PHYLUM EXAMPLES
(A) Coelenterata (i) Snail
(B) Platyhelminthes (ii) Starfish
(C) Echinodermata (iii) Tapeworm
(D) Mollusca (iv) Hydra

Answer:
A – iv, B – iii, C – ii, D – i

V. Answer very briefly :

Question 1.
Define taxonomy.
Answer:
The theoretical study of classification includes its basic principles, procedures, and rules.

Question 2.
What is nematocyst?
Answer:
The tentacles of organisms belonging to phylum Coelenterata bear stinging cells called cnidoblast or nematocyst.

 Samacheer Kalvi 9th Science Guide Chapter 17 Animal Kingdom

Question 3.
Why coelenterates are called diploblastic animals?
Answer:
The animals in phylum coelenterates have two layers the outer ectoderm and the inner endoderm in the body wall. So they are called diploblastic animals.

Question 4.
List the respiratory organs of amphibians.
Answer:
Respiration is through by gills, skin, buccopharynx and lungs.

Question 5.
How does locomotion take place in starfish?
Answer:
Locomotion is affected by tube feet.

 Samacheer Kalvi 9th Science Guide Chapter 17 Animal Kingdom

Question 6.
Are jellyfish and starfish similar to fishes? If no justify the answer.
Answer:

  • Jellyfish is a coelenterate. Their bodies are made of calcium carbonate.
  • Starfish fish is an echinoderm. Their bodies are made of calcium carbonate.
  • Catfish is a fish species.
  • Jellyfish and starfish are invertebrates.
  • Fishes are vertebrates.

Question 7.
Why are frogs said to be amphibians?
Answer:
The frogs have dual adaptation in land and aquatic environments. So they are called amphibians.

VI. Answer briefly:

Question 1.
Give an account on phylum Annelida.
Answer:

  • These are bilaterally symmetrical, triploblastic, first true coelomate animals with an organ-system grade of organization.
  • Body is externally divided into segments called metameres joined by ring-like structures called annuli.
  • It is covered by a moist thin cuticle.
  • Setae and parapodia are locomotor organs.
  • Sexes may be separate or ünited (hermaphrodites).
    e.g- Nereis, Earthworm, Leech.

 Samacheer Kalvi 9th Science Guide Chapter 17 Animal Kingdom

Question 2.
Differentiate between flatworms and roundworms?
Answer:

Flatworms Roundworms
a) They belong to Phylum Platyhelminthes. They belong to Phylum Aschelminthes.
b) They are mostly parasitic. Exist as free-living soil forms or as parasites.
c) Mostly hermaphrodites. Sexual dimorphism is seen.
d) They are acoelomate organisms. They are pseudocoelomate organisms.
e) The alimentary canal is absent or simple.
Eg: Tapeworm.
The alimentary canal is a straight tube.
Eg: Roundworm.

Question3.
Outline the flow charts of Phylum Chordata.
Answer:
Classification of phylum Chordata:
Samacheer Kalvi 9th Science Guide Chapter 17 Animal Kingdom 1

Question 4.
List five characteristic features of fishes.
Answer:

  • Fishes are poikilothermic, whose internal temperature varies, considerably.
  • The body has a covering of scales.
  • Body muscles are arranged into segments called myotomes.
  • The body is differentiated into head, trunk and tail.
  • Respiration is done by 5 to7 pairs of gills, which are covered by an operculum or sometimes maybe naked.

 Samacheer Kalvi 9th Science Guide Chapter 17 Animal Kingdom

Question 5.
Comment on the aquatic and terrestrial habits of amphibians.
Answer:
Aquatic habits of amphibians:

  • The larva of amphibians (tadpole) lives in water and breathes with gills.
  • External fertilization occurs in frog with water as a medium of fertilization.
  • The adult frog has webbed feet to swim in water.
  • The skin is moist and glandular which helps in Respiration.

Terrestrial habits of amphibians:

  • The adults live on land and breathe through the lungs. Bucco-pharynx also helps in Respiration.
  • The forelimbs are short and help to hop on land.

Question 6.
How are the limbs of the birds adapted for avian life?
Answer:

  1. Birds have a spindle-shaped body.
  2. The forelimbs are modified as wings for aerial locomotion.
  3. The air sacs present in the birds, make the bird lightweight.
  4. The body is covered with feathers.

 Samacheer Kalvi 9th Science Guide Chapter 17 Animal Kingdom

VII. Answer in detail :

Question 1.
Describe the characteristic features of different Prochordates.
Answer:
Prochordata :

  • The urochordates are considered as the forerunner of vertebrates.
  • Based on the nature of the notochord, protochordate is classified into subphylum Urochordata and subphylum Cephalochordata.
    Phylum Hemichordata :
    Samacheer Kalvi 9th Science Guide Chapter 17 Animal Kingdom 2
  • Hemichordates are marine organisms with soft, vermiform and unsegmented body.
  • They are bilaterally symmetrical, coelomate animals with non-chordate and chordate features.
  • They have gill slits but do not have notochord.
  • They are ciliary feeders and mostly remain as tubiculous forms, e.g- Balanoglossus (Acorn worms).
    Subphylum Urochordata:
    Samacheer Kalvi 9th Science Guide Chapter 17 Animal Kingdom 3
  • Notochord is present only in the tail region of free-living larva, e.g. Ascidian
  • Adults are sessile forms and mostly degenerate.
  • The body is covered with a tunic or test.

Subphylum Cephalochordata :

  • Cephalochordates are small fish like marine chordates with unpaired dorsal fins.
  • The notochord extends throughout the entire length of the body. e.g. Amphioxus

Question 2.
Give an account on phylum Arthropoda.
Answer:

  • Arthropoda is the largest phylum.
  • The organisms have jointed legs.
  • The body is segmented into head, thorax and abdomen.
  • The exoskeleton is made up of chitin.
  • The coelomic cavity is filled with haemolymph (blood).
  • They do not have defined blood vessels. This is called open circulatory system.
  • The insects shed the exoskeleton and this process is called moulting.
  • Small Arthropods absorb oxygen through the body and larger aquatic species breathe through book gills.
  • Land Arthropods breathe through a system of tiny body tubes called tracheae.
  • Excretion occurs through malphigian tubules and through green glands in crabs and prawns. .
  • Insects, spiders, crabs, shrimps, butterflies, millipedes, centipedes, and scorpions are some arthropods.

 Samacheer Kalvi 9th Science Guide Chapter 17 Animal Kingdom

Intext activities

ACTIVITY – 1
Samacheer Kalvi 9th Science Guide Chapter 17 Animal Kingdom 5
Observation :

  • Scorpion
  • Arachnid
  • Cockroach
  • Crab
  • Crustacean
    [End of the activity]

9th Science Guide Animal Kingdom Additional Important Questions and Answers

I. Choose the correct answer:

Question 1.
Which is not an insect?
(a) Housefly
(b) Bedbug
(c) Mosquito
(d) Spider
Answer:
d) Spider

Question 2.
Which is not a feature of chordates?
(a) Green glands
(b) Sweat glands
(c) Sebaceous gland
(d) Mammary gland
Answer:
(a) Green glands

 Samacheer Kalvi 9th Science Guide Chapter 17 Animal Kingdom

Question 3.
Choose the correct terms related to Hemichordate
(a) Vermiform, unsegmented, bilaterally symmetrical, ciliary feeders
(b) Vermiform, segmented, triploblastic, ciliary feeders
(c) Vermiform, unsegmented, diploblastic, ciliary feeders
(d) Vermiform, unsegmented; triploblastic, filter feeders
Answer:
a) Vermiform, unsegmented, bilaterally symmetrical, ciliary feeders

Question 4.
The …………. can swim faster than a cheetah.
(a) Sail fish
(b) Catfish
(c) Jelly fish
(d) Sucker fish
Answer:
a) Sail fish

 Samacheer Kalvi 9th Science Guide Chapter 17 Animal Kingdom

Question 5.
The biggest vertebrate animal is the ……………….
(a) Blue whale
(b) Dolphin
(c) Elephant
(d) Rhinoceros
Answer:
(a) Blue whale

Question 6.
Who introduced binomial nomenclature?
(a) Huxley
(b) Carolus Linnaeus
(c) Nicolaus Copernicus
(d) Charles Darwin
Answer:
(b) Carolus Linnaeus

 Samacheer Kalvi 9th Science Guide Chapter 17 Animal Kingdom

Question 7.
What is the binomial name of tapeworm?
(a) Ascaris lumbricoides
(b) Taenia solium
(c) Lampito mauritii
(d) Hirudinaria granulosa
Answer:
(b) Taenia solium

Question 8.
Which is the state bird of Tamil Nadu?
(a) Peacock
(b) Parrot
(c) Emerald dove
(d) Eagle
Answer:
(c) Emerald dove

Question 9. ;
……………. is an example of bony fish.
(a) Mullets
(b) Sharks
(c) Skates
(d) Hagfish
Answer:
(a) Mullets

 Samacheer Kalvi 9th Science Guide Chapter 17 Animal Kingdom

Question 10.
The notochord extends throughout the entire length of the body.
(a) Acorn worms
(b) Lamprey
(c) Ascidian
(d) Amphioxus
Answer:
(d) Amphioxus

Question 11.
Animals which possess notochord are called as …………………
(a) invertebrates
(b) non-chordates
(c) chordates
(d) all the above
Answer:
(c) chordates

 Samacheer Kalvi 9th Science Guide Chapter 17 Animal Kingdom

Question 12.
What ¡s the name of the bone which is filled with air?
(a) Flat bones
(b) Irregular bones
(c) Short bones
(d) Pneumatic bones
Answer:
d) Pneumatic bones

Question 13.
_________ ¡s the unique characteristic feature of mammals.
(a) Placenta
(b) Egg
(c) Tail
(d) Ear
Answer:
(a) Placenta

Question 14.
________ have gill slits but do not have notochord.
(a) Phylum Hemichordata
(b) Phylum Echirodermata
(c) Phylum Mollusca
(d) Phylum Annelida
Answer:
Phylum Hemichordata

 Samacheer Kalvi 9th Science Guide Chapter 17 Animal Kingdom

II. Fill In the blanks:

1. The binomial name of our National Bird is …………………………
Answer:
pavocristatus

2. In mammals testis are enclosed by ………………….
Answer:
scrotal sacs

3. In birds, the air sacs communicate with …………………
Answer:
lungs

 Samacheer Kalvi 9th Science Guide Chapter 17 Animal Kingdom

4. The animals belonging to phylunm …………….. are said to be soft-bodied.
Answer:
mollusca

5. The name ………….. means “thousand legs”.
Answer:
millipede

6. The skeletal framework of phylum Porifera is made up of ……………..
Answer:
spicules

 Samacheer Kalvi 9th Science Guide Chapter 17 Animal Kingdom

7. A true body cavity is located within ………………
Answer:
mesoderm

8………………. separates the digestive tract from the body wall.
Answer:
Coelom

9. ……………….. formed during embryonic development.
Answer:
Notochord

 Samacheer Kalvi 9th Science Guide Chapter 17 Animal Kingdom

10. …………….. is the largest phylum of the animal kingdom.
Answer:
Arthropoda

11. ………………… is a fluid-filled body cavity.
Answer:
Coelom

12. The body cavity of the phylum Aschelminthes is …………………….
Answer:
pseudocoelom

 Samacheer Kalvi 9th Science Guide Chapter 17 Animal Kingdom

13. The most common diseases caused by nematodes in human beings are …………and ……………
Answer:
elephantiasis, ascariasis

14. Cyclostmes are ………………….
Answer:
jawless vertebrates

15. Malphigian tubules also called as ……………….
Answer:
green glands

 Samacheer Kalvi 9th Science Guide Chapter 17 Animal Kingdom

16. Locomotion of phylum Echinodermata is affected by .
Answer:
tube feet

III. Analogy:

Question 1.
Echinodermata: ________ : : Soft Bodies Animals: ________
Answer:
Spiny Skinned Animals; Mollusca.

Question2.
Birds: _______ : : _________ : Cold-blooded.
Answer:
Warm-blooded; Fishes.

IV. State whether true or false. If false write the correct statement:

1. Order is a number of related families having common characters are placed in an order.
Answer:
True.

2. Tissue organization can be seen in phylum Porifera.
Answer:
False.
Correct statement: Cellular grade of organization can be seen in phylum Porifera.

 Samacheer Kalvi 9th Science Guide Chapter 17 Animal Kingdom

3. Aschelminthes is the largest phylum of the animal kingdom.
Answer:
False.
Correct statement: Arthropods is the largest phylum of the animal kingdom.

4. In the animals belonging to phylum Echinodermata, the body is divided into head, muscular food and visceral mass………….
Answer:
False.
Correct statement: In phylum mollusca, the body is divided into head, muscular food and visceral mass.

5. Setae and parapodia are locomotor organs of earthworms.
Answer:
True.

 Samacheer Kalvi 9th Science Guide Chapter 17 Animal Kingdom

6. Mammals have four-chambered Hearts.
Answer:
True,

V. Match the following:

Question 1.

(A) Cartilaginous (i) Mullets
(B) Bony fishes (ii) Sharks
(C) Pneumatic bones (iii) Reptiles
(D) Three chambered heart (iv) Birds

Answer:
A – i, B – ii, C – iv, D – iii

 Samacheer Kalvi 9th Science Guide Chapter 17 Animal Kingdom

VI. Assertion and Reason type :

Question 1.
Assertion (A) : The Arthropods have an open circulatory system. .
Reason (R) : The cells and tissues are bathed in blood.
(a) A is right and R is wrong.
(b) A is the wrong R is right.
(c) A and R are wrong.
(d) A is right R explains A.
Answer:
(d) A is right R explains A

Question 2.
Assertion (A) : Mammals give birth to their young ones.
Reason (R) : Platypus is an egg-laying mammal.
(a) A and R are correct.
(b) A and R are wrong.
(c) R explains A.
(d) A is the wrong R is right.
Answer:
(a) A and R are correct

 Samacheer Kalvi 9th Science Guide Chapter 17 Animal Kingdom

VII. Answer in one or two sentences :

Question 1.
Which organism is called Friends of farmers? Why?
Answer:
Earthworms are called ‘Friends of the farmers’ because after digesting organic matter, earthworms excrete a nutrient-rich waste product called castings which are used as Vermicompost.

Question 2.
What are the sub-phylum of prochordates?
Answer:
Sub phylum of prochordates are
Subphylum Cephalochordata
Subphylum Urochordata

Question 3.
Name the three germ layers.,
Answer:
Ectoderm, mesoderm and endoderm

 Samacheer Kalvi 9th Science Guide Chapter 17 Animal Kingdom

Question 4.
Name the locomotary organs seen in phylum protozoa.
Answer:
Pseudopodia, cilia, or flagella.

Question 5.
Mention two special features of mammals.
Answer:
(i) External ear or pinna is seen in most the mammals.
(ii) Presence of the placenta is a unique characteristic feature.

Question 6.
Write the binomials of a) Man b) Tapeworm
Answer:
a) Homo sapiens
b) Taenia solium.

 Samacheer Kalvi 9th Science Guide Chapter 17 Animal Kingdom

Question 7.
What is the binomial name?
Answer:
Carolus Linnaeus introduced the method of naming the animals with two names. This is known as binomial name and is followed universally.
Eg: Binomial of frog is
Samacheer Kalvi 9th Science Guide Chapter 17 Animal Kingdom 6

VIII. Short answer questions :

Question 1.
How is the body wall of coelenterates arranged?
Answer:
Body wall of coelenterate is disloblastic with two layers, namely the outer ectoderm and the inner endoderm, are separated by non-cellular jelly-like substance called mesoglea. Due to the presence of two layers in the body wall, they are said to be diploblastic animals.

Question 2.
What is polymorphism?
Answer:
Many coelenterates exhibit polymorphism, which is the variation in the structure and function of the individuals of the same species. They reproduce both asexually and sexually, e.g. Hydra, Jellyfish.

 Samacheer Kalvi 9th Science Guide Chapter 17 Animal Kingdom

Question 3.
What is the unique feature of chordates?
Answer:
Presence of notochord is the unique feature of chordates.

Question 4.
On the basis of position of notochord, classify the different prochordates. Justify your answer.
Answer:

Subphyla of prochordates Position of notochord
b) Cephalochordata The notochord is present only in the tail region of the free-living larva. e.g. Ascidian
c) Urochordata The notochord extends throughout the entire length of the body. e.g. Amphioxus

Question 5.
List the integumentary glands of mammals.
Answer:
Integumentary glands are seen in mammals:

  • Sweat glands
  • Sebaceous glands
  • Scent glands
  • Mammary glands are modified
  • Integumentary glands

 Samacheer Kalvi 9th Science Guide Chapter 17 Animal Kingdom

Question 6.
How is the reproductive characters of mammals different from those of aves.

Mammals

Aves

(i) Mammals have paired sex organs, eggs are small with little or no yolk. (i) They are oviparous and lay eggs.
(ii) They are viviparous and give birth to young one. (ii) Formation of placenta is not seen. The embryo is nourished,by egg yolk. Egg has an abundant quantity of yolk.
(iii) Formation of placenta is a special feature. The tissue connects the foetus to maternal tissues.

Question 7.
Mention two characteristic features of phylum Echinodermata.
Answer:
They have a water vascular system which is a unique feature. Locomotion is affected by tube feet.

Question 8.
Mention two features seen in Aves to aid in flying.
Answer:

  • The forelimbs are modified into wings for flight.
  • Bones are filled with air (pneumatic bones), which reduces body weight.

 Samacheer Kalvi 9th Science Guide Chapter 17 Animal Kingdom

Question 9.
Why is crocodile unique among reptiles?
Answer:
It has a four-chambered heart whereas the reptiles have a three-chambered heart.

Question 10
Why are eggs of reptiles covered with shell unlike eggs of amphibians?
Answer:
First-class of vertebrates adapted for terrestrial life and lay their eggs with tough outer Shell e.g Calotes, Lizard, Snake, Tortoise, Turtle. Hence the eggs are covered with shells to protect them. Whereas amphibians eggs are laid in water.

Question 11.
What are pneumatic bones?
Answer:
The bones are filled with air. So they are called pneumatic bones and are seen in aves.

 Samacheer Kalvi 9th Science Guide Chapter 17 Animal Kingdom

IX. Long answer questions :

Question 1.
Write a note on mammals.
Answer:

  • Mammals are -warm-blooded animals.
  • The skin is covered with hair. It also bears sweat and sebaceous (oil) glands.
  • The body is divisible into head, neck, trunk and tail.
  • Females have mammary glands, which secrete milk for feeding the young ones.
  • The external ear or pinnae is present.
  • Heart is four-chambered and they breathe through lungs.
  • Except egg-laying mammals (Platypus, and Spiny anteater), all other mammals give birth to their young ones (viviparous).
  • Placenta is the unique characteristic feature of mammals, e.g Rat, Rabbit, Man.

Question 2.
Write a note on aves.
Answer:

  • Birds are homeothermic (warm-blooded) animals with several adaptations to fly.
  • The spindle or boat-shaped body is divisible into head, neck, trunk and tail.
  • The body is covered with feathers. Forelimbs are modified into wings for flight.
  • Hindlimbs are adapted for walking, perching or swimming.
  • The respiration is through lungs, which have air sacs.
  • Bones are filled with air (pneumatic bones), which reduces body weight.
  • They lay large yolk laden eggs.
  • They are covered by hard calcareous shell, e.g. Parrot, Crow, Eagle, Pigeon, Ostrich.

Question 3.
Outline the flow chart of invertebrate phyla.
Answer:
Samacheer Kalvi 9th Science Guide Chapter 17 Animal Kingdom 7