Category: Class 10

Students can download 10th Social Science Civics Chapter 3 State Government Questions and Answers, Notes, Samacheer Kalvi 10th Social Science 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 10th Social Science Solutions Civics Chapter 3 State Government

Samacheer Kalvi 10th Social Science State Government Text Book Back Questions and Answers

I. Choose the correct answer

Question 1.
The Governor of the State is appointed by the:
(a) Prime Minister
(b) Chief Minister
(c) President
(d) Chief Justice
Answer:
(c) President

Question 2.
The Speaker of a State is a ……………
(a) Head of State
(b) Head of government
(c) President’s agent
(d) None of these
Answer:
(d) None of these

Question 3.
Which among the following is not one of the powers of the Governor?
(a) Legislative
(b) Executive
(c) Judicial
(d) Diplomatic
Answer:
(d) Diplomatic

Question 4.
Who can nominate one representative of the Anglo-Indian Community to the State Legislative Assembly?
(a) The President
(b) The Governor
(c) The Chief Minister
(d) The Speaker of State legislature
Answer:
(b) The Governor

Question 5.
The Governor does not appoint:
(a) Chief Minister
(b) Chairman of the State Public Service Commission
(c) Advocate General of the State
(d) Judges of the High Court
Answer:
(d) Judges of the High Court

Question 6.
The Chief Minister of a State is appointed by …………….
(a) The State Legislature
(b) The Governor
(c) The President
(d) The Speaker of State Legislative Assembly
Answer:
(b) The Governor

Question 7.
The State Council of Ministers is headed by:
(a) The Chief Minister
(b) The Governor
(c) The Speaker
(d) The Prime Minister
Answer:
(a) The Chief Minister

Question 8.
The Legislative Council ………….
(a) has a term of five years
(b) has a term of six years
(c) is a permanent house
(d) has a term of four years
Answer:
(c) is a permanent house

Question 9.
The minimum age for the membership of the Legislative Council is:
(a) 25 years
(b) 21 years
(c) 30 years
(d) 35 years
Answer:
(c) 30 years

Question 10.
The members of the Legislative Council are ……………
(a) Elected by the Legislative Assembly
(b) Mostly nominated
(c) Elected by local bodies, graduates, teachers, Legislative Assembly etc.
(d) Directly elected by the people
Answer:
(c) Elected by local bodies, graduates, teachers, Legislative Assembly etc.

Question 11.
Which one of the following States does not possess a bicameral legislature?
(a) Andhra Pradesh
(b) Telangana
(c) Tamil Nadu
(d) Uttar Pradesh
Answer:
(c) Tamil Nadu

Question 12.
The High Courts in India were first started at ………………….
(a) Calcutta, Bombay, Madras
(b) Delhi and Calcutta
(c) Delhi, Calcutta, Madras
(d) Calcutta, Madras, Delhi
Answer:
(a) Calcutta, Bombay, Madras

Question 13.
Which of the following States have a common High Court?
(a) Tamil Nadu and Andhra Pradesh
(b) Kerala and Telangana
(c) Punjab and Haryana
(d) Maharashtra and Gujarat
Answer:
(c) Punjab and Haryana

II. Fill in the blanks

1. Governor of the state government surrenders his resignation to ………………..
2. Members of the Legislative assembly (MLAs) elected by the ………………..
3. ……………….. is the first women Governor of Tamil Nadu.
4. ……………….. acts as the chancellor of universities in the state.
5. The Seventh Amendment Act of ……………….. authorised the Parliament to establish a common high court for two or more states.
6. The Chairman and Members of the State Public Service Commission can be removed only by the ………………..

Answers:

1. The President
2. people
3. Mrs.Fathima Beevi
4. The Governor
5. 1956
6. President

III. Match the following

Answer:
A. (ii)
B. (i)
C. (iv)
D. (v)
E. (iii)

IV. Choose the correct statement

Question 1.
(i) Only some states in India have Legislative Councils.
(ii) Some members of Legislative Councils are nominated.
(iii) Some members of Legislative Councils are directly elected by the people.
(iv) Some members are elected by Local bodies.
(a) (ii) and (iv) are correct
(b) (iii) and (iv) are correct
(c) (i) and iv are correct
(d) (i), (ii) and (iii) are correct
(e) (i), (ii) and (iv) are correct
Answer:
(e) (i), (ii) and (iv) are correct

Question 2.
Assertion (A): There are limitations on the Legislative authority of the State Legislature.
Reason (R): Certain bills on the State List can be introduced in the State
Legislature only with the President’s approval.
(a) (A) is false but (R) is true
(b) (A) is true but (R) is false
(c) Both (A) and (R) are true and (R) is the correct reason for (A)
(d) Both (A) and (R) are true and (R) is not the correct reason for (A).
Answer:
(c) Both (A) and (R) are true and (R) is the correct reason for (A)

V. Answer in brief questions

Question 1.
How the state of Jammu and Kashmir differ from the other states of India?
Answer:
(i) The Constitution of India grants special status to Jammu and Kashmir among Indian States, and it is the only state in India to have a separate Constitution.

(ii) The Directive Principles of the State Policy and Fundamental Duties of the Constitution are not applicable to the State of Jammu and Kashmir.

(iii) Rights to property, which is denied as a Fundamental Right to rest of India is still guaranteed in Jammu and Kashmir.

Question 2.
What is the importance of the Governor of a state?
Answer:

1. The Governor is the constitutional head of the state executive.
2. The administration of a state is carried on in the name of the governor.
3. The Governor is an integral part of the state legislature. But he is not a member in the legislature.
4. He has the right to summon, prorogue the state legislature and dissolve the Assembly.
5. Under Article 213 he can promulgate ordinances when the state legislature is not in session.

Question 3.
What are the qualifications for the appointment of Governor?
Answer:
Qualifications of the Governor is given below

1. He should be a citizen of India.
2. He must have completed 35 years of age.
3. He should not be a member of Parliament or any State legislature.
4. He should not hold any other profitable occupation.

Question 4.
What is the original Jurisdiction of the High Court?
Answer:

1. Only in matters of admiralty, probate, matrimonial and contempt of Court the High Courts have original Jurisdiction.
2. The presidency High Courts ( Bombay, Calcutta and Madras) have original Jurisdiction in which the amount involved is more than 2000 and the criminal cases which are committed to them by the presidency magistrates.

Question 5.
What do you understand by the “Appellate Jurisdiction” of the High Court?
Answer:
As courts of appeal, all High Courts hear appeals in both civil and criminal cases against the divisions of the subordinate courts and can review their judgements.

VI. Answer in Detail

Question 1.
What are the powers and functions of the Chief Minister?
Answer:

1. The leader of the majority’ party or majority group in the state Legislative Assembly is appointed as the Chief Minister by the Governor.
2. The Chief Minister is the real executive head of the state administration.

The Powers and Functions of the Chief Minister:

1. Relating to the council of Ministers
2. Relating to the Governor
3. Relating to the State Legislature
4. Other functions and powers

Relating to the Council of Ministers:

1. The Chief Minister recommends a person who can be appointed as Minister by the Governor.
2. He allocates the port folios to the Ministers
3. He shuffles and reshuffles his ministry
4. He presides over the cabinet meetings and influences its decisions,
5. In case of difference of opinion he can ask a minister to resign or advices the Governor to dismiss him,
6. If the Chief Minister resigns the council of Ministers are also should resign.
7. He guides, directs, controls and coordinates the activities of all the Ministers.

Relating to the Governor:

1. The Chief Minister is the link between the Governor and the Council of Ministers.
2. He advices the Governor in relation to the appointment of Advocate general of the state, State Election Commissioner, Chairman and members of the State Planning Commission, State Public Service Commission and the State Finance Commission.

Relating to State Legislature:

1. On the advice of the Chief Minister Governor officially summons & prorogues the sessions of the state legislature.
2. He announces the government policies on the floor of the house.
3. He can introduce the bills in the Legislative Assembly.
4. Recommend for the dissolution of the Legislative Assembly to the Governor any time.

Other function and powers:

1. As the leader of the party he has to control the party and develop the disciplines.
2. To consider the demands of the different sections of the people.
3. As the political head supervise control and co-ordinate the secretaries of various departments in the state level.
4. For the smooth functioning of the state he has to develop a good rapport with the Central (Union) Government for good Centre-State relation.

Question 2.
Describe the various powers and functions of the Governor.
Answer:
The powers and functions of the Governor are:
(i) The Governor is the Constitutional head of the State. All the administration is carried on in his name.

(ii) He appoints the leader of the majority party in the State Legislative Assembly as the Chief Minister of the State. He appoints other members of the council of Ministers on the recommendation of the Chief Minister.

(iii) He appoints the Advocate General of the State, the chairman and members of the State Public Service Commission, the State Election Commissioner, the Attorney General of the State etc.

(iv) He has the right to summon, prorogue the State Legislature and dissolve the State Legislative Assembly.

(v) The Money Bills can be introduced in the State Legislature only with the prior recommendation of the Governor.

(vi) He constitutes a Finance Commission after every five years to review the financial position of the panchayats and the municipalities.

Question 3.
Briefly discuss the Functions of the State Legislature.
Answer:
Legislative powers:

1. As per the constitution can pass laws on all subjects mentioned in the State List.
2. The passing of Bill into law follows the same procedure as in the union Parliament.
3. The state can make laws on concurrent subject also. The state made law will become inoperative when the Centre also passes law on the same subject.
4. The Bill passed in the State legislature will become law after Governor’s assent.

Financial powers:

1. Money bills can be introduced only in the Lower House or Assembly
2. No new tax can be levied without the sanction and permission of the Assembly.
3. The Legislature controls the finances of the State.

Control over the Executive:

1. The Legislature controls over the Executive.
2. The Council of Ministers is responsible to the Assembly.
3. They can be removed from the power if the Assembly passes “No confidence motion” against the Ministry.

Question 4.
Critically examine the functions and powers of the Council of Ministers.
Answer:
The functions and powers of the Council of Ministers –

1. It formulates and decides the policies of the State and implements them effectively.
2. It decides the legislative programmes of the Legislative Assembly and sponsors all important bills.
3. It controls the financial policy and decides the tax structure for the public welfare of the State.
4. It chalks out programmes and schemes for the socio-economic changes so that the State makes headway in various inter-related fields,
5. It makes the important appointments of the heads of departments.
6. The Annual Financial Statement called as the Budget is finalised by the Council of Ministers.
7. It advises the Governor on the appointment of judges of the subordinate courts.

Question 5.
Describe the powers and functions of the High Court
Answer:
High Court is the highest court in the state. Every High Court consists of a Chief Justice and other judges appointed by the President. The High Court enjoys the following Jurisdiction.

(i) Original Jurisdiction: The High Court can hear the cases like such as matters of admiralty, probate and matrimonial, contempt of court and in criminal cases.

(ii) Appellate Jurisdiction: As courts of appeal all High Courts appeals in civil and criminal cases and also cases of their own.

(iii) Writ Jurisdiction: Writs are issued by the High Court not only for the enforcement of fundamental rights but also where an ordinary legal rights has been infringed.

Kinds of Writs: Habeas Corpus, Mandamus, Prohibition ,Quo Warranto, Certiorari.

(iv) Supervisory Jurisdiction:

(a) High Court has the power of superintendence over all courts and tribunals, (except military courts)
(b) High Court has an administrative powers.
(c) Its law is binding on all subordinate courts functioning within its territorial jurisdiction.
(d) It is consulted by the governor in the matters of appointment , posting and promotion, grant of leave, transfers and discipline court of Record.
(e) All the decisions and decrees issued by the High Court are printed and kept as a record for future needs.

Judicial Review: To examine the constitutionality of Legislative enactments and executive orders of both the central and the State Governments.

VII. Project & Activity

Question 1.
Prepare a flow chart showing the State Government’s Administrative setup.
Answer:

Question 2.
Students to list out the names of the Tamil Nadu Governor, Chief Minister, Ministers and the Governors and Chief Ministers of the neighbouring States.
Answer:

Samacheer Kalvi 10th Social Science State Government Additional Important Questions and Answers

I. Choose the Correct Answer

Question 1.
The State of ……………… has a separate constitution.
(a) Punjab & Haryana
(b) Jammu & Kashmir
(c) Kerala & Karnataka
(d) None of these
Answer:
(b) Jammu & Kashmir

Question 2.
Who is not appointed by the Governor?
(a) The Advocate General of the State
(b) The State Election Commissioner
(c) The Chairman of the State Public Service Commission
(d) The Chief Justice of the High Court
Answer:
(d) The Chief Justice of the High Court

Question 3.
The administration of the State is carried on in the name of the:
(a) Chief Minister
(b) Council of Ministers
(c) Speaker
(d) Governor
Answer:
(d) Governor

Question 4.
How many High Courts are there for all 29 States?
(a) 29
(b) 27
(c) 25
(d) 22
Answer:
(c) 25

Question 5.
The ……………… has the power to summon, prorogue the State Legislative Assembly.
(a) President
(b) Governor
(c) Chief Minister
(d) Chairman of the Legislative Council
Answer:
(b) Governor

Question 6.
The State Government consists of …………… branches.
(a) two
(b) three
(c) five
Answer:
(b) three

Question 7.
Under Article ……………… the Governor can pass ordinance when the State Assembly is not in session.
(a) 311
(b) 312
(c) 213
(d) 32
Answer:
(c) 213

Question 8.
The ……………. provides a legislature for every state.
(a) Constitution
(b) Lok Sabha
(c) Rashtrapathi Bhavan
Answer:
(a) Constitution

Question 9.
The total strength of Legislative Assembly of Tamil Nadu is:
(aj 231
(b) 240
(c) 245
(d) 235
Answer:
(d) 235

Question 10.
……………… can introduce the Bills in the Legislative Assembly.
(a) Prime Minister
(b) Advocate general
(c) Chief Minister
Answer:
(c) Chief Minister

Question 11.
The institution of High Court originated in India in:
(a) 1826
(b) 1816
(c) 1862
(d) 1870
Answer:
(c) 1862

Question 12.
The Statue of ……………… has been kept in front of the High Court building.
(a) Rajaraja Cholan
(b) Sama Needhi Kanda Cholan (Manu needhi Cholan)
(c) Karikal Cholan
(d) Rajendra Cholan
Answer:
(b) Sama Needhi Kanda Cholan (Manu needhi Cholan)

II. Fill in the blanks

1. Article 226 and 227 confer the power of ……………….. on a high court.
2. The ……………….. is the real centre of power in the State.
3. The Legislature of s State or a High Court has no power in the removal of ………………..
4. The present Chief Minister of Tamil Nadu is ………………..
5. The present Governor of Tamil Nadu is ………………..
6. The maximum strength of the Legislative Assembly must not below ………………..
7. The Standing committee of the Cabinet is ………………..
8. The ……………….. is removed from the office by a resolution of the Assembly after giving a 14 days notice.
9. The Legislative Council is the ……………….. of the State legislature.
10. Article ……………….. deals with the creation or abolition of Legislative Council.

Answers:

1. Judicial review
2. Legislative Assembly
3. Governor
4. Thiru Edappadi K. Palaniswami
5. Thiru Banvarilal Purohit
6. Sixty
7. Permanent
8. Speaker
9. Upper House
10. 169

III. Match the following

Question 1.
Match the Column I with Column II.


Answer:
A. (v)
B. (iv)
C. (i)
D. (ii)
E. (iii)

Question 2.
Match the Column I with Column II.

Answer:
A. (iv)
B. (i)
C. (v)
D. (ii)
E. (iii)

IV. Choose the correct statement

Question 1.
Assertion (A): The term of the Chief Minister is not fixed.
Reason (R): He may remain as the Chief Minister as long as he enjoys the support of the majority of the members of the State Legislative Assembly.
(a) Both (A) and (R) are true and (R) is the correct reason for (A)
(b) (A) is false (R) is true
(c) Both (A) and (R) are true and (R) is not the correct reason
(d) (A) is true but (R) is false
Answer:
(a) Both (A) and (R) are true and (R) is the correct reason for (A)

Question 2.
Assertion (A): The number of judges varies from State to State.
Reason (R): The number of judges of each High Court is determined by the President. .
(a) (A) is false (R) is true
(b) Both (A) and (R) are correct (R) is the correct reason for A
(c) (A) and (R) are true and (R) is not the correct reason for A
(d) (A) is true (R) is false
Answer:
(b) Both (A) and (R) are correct (R) is the correct reason for A

Question 3.
(i) High Courts are given power to issue writs under Article 226 of the constitution.
(ii) The jurisdiction is limited only to the fundamental rights.
(iii) Writs are issued by the High Court when an ordinary legal right has been fringed.
(iv) Article 32 empowered to issue such writs.
(a) (i) and (ii) are correct
(b) (i), (iii) and (iv) are correct
(c) (i) and (iii) are correct
(d) (iii) and (iv) are correct
Answer:
(c) (i) and (iii) are correct

Question 4.
(i) Council of Ministers work as a team under the Chief Minister.
(ii) Council of Ministers are collectively responsible to the State Assembly.
(iii) The State ministry will be in power after the resignation of the Chief Minister.
(iv) Councils of Ministers do not aid and advice the Governor.
(a) (i) and (ii) are correct
(b) (ii) and (iii) are correct
(c) (ii) and (iv) are correct
(d) (iii) and (iv) are correct
Answer:
(a) (i) and (ii) are correct

V. Answer in brief

Question 1.
Write a short note on cabinet and cabinet committees.
Answer:
The Cabinet is the nucleus of the Council of Ministers. It consists of only the Cabinet Ministers. It is the real centre of authority in the State Government.
The cabinet works through various committees called Cabinet Committees. They are of two types – standing and ad hoc – the former are of a permanent nature while the latter are of a temporary nature.

Question 2.
How the Governor is appointed to a state?
Answer:

1. The Governor of a state is appointed by the President.
2. Generally, the Governor does not belongs to the state where he is appointed.
3. He also be transferred from one State to another.
4. If situation warrants so, the same person may be appointed as the Governor of two or more States.
5. Usually the term of office is five years but he may be appointed as a Governor any number of terms during the pleasure of the President.

Question 3.
Throw light on the emergency powers of the Governor.
Answer:
If the Governor is convinced that the Government of the State is not carried on in accordance with the provisions of the constitution, he may recommend to the President to impose Present Rule in that State. As soon as the President Rule is imposed, the administration of the State is carried on by the Governor as the representative of the President.

Question 4.
What is the strength of Tamil Nadu Legislative Assembly?
Answer:
In Tamil Nadu according to the strength of legislative Assembly (234 +1) . 234 members are directly elected by the people from the constituencies on the basis of adult franchise and one member is nominated by the Governor from Anglo-Indian community.

Question 5.
How are the members of the Legislative Council elected?
Answer:
The members of the Legislative Council or the Upper House are elected in the following ways.

• 1/3 of the members are elected by local bodies. .
• 1/12 of the members are elected by graduates of the universities in the State.
• 1/12 of the members are elected by the graduate teachers.
• 1/3 of the members are elected by the members of the Legislative Assembly.
• 1/6 is nominated by the Governor who is eminent in the field of literary excellence, art, social or cooperates.

Question 6.
Write a brief note on the High Court of Madras?
Answer:

1. The High Court of Madras is the one of the three High Courts in India, established in the three presidency Towns of Bombay, Calcutta and Madras by letters patent granted by Queen Victoria dated 26th June 1862.
2. The High Court building is the second largest Judicial complex in the world after London.

Question 7.
Where were High Courts first established and when?
Answer:
High Courts were first established in the three Presidency cities of Calcutta, Bombay and Madras in 1862.

Question 8.
How many High Courts are there in our country and who decides the number of judges to each High court?
Answer:

1. At present there are 25 High courts for 29 states (including New Andhra Pradesh High court established in 1st January 2019 at Amaravati) and seven union territories.
2. The number of judges of each High Court is determined by the President.

Question 9.
What do you mean by appellate system?
Answer:
It means that a person can appeal to a higher Court if they are not satisfied with the judgement of the lower Court.

Question 10.
Which Amendment abolished the power of Judicial Review by the state High Court? And by which amendment it was restored?
Answer:

1. The 42nd amendment of 1976 curtailed the power of Judicial Review by the High Court.
2. It debarred the constitutional validity of any central law.
3. The 43rd Amendment Act of 1977 restored the original position.

VI. Answer in Detail

Question 1.
What are all the privileges enjoyed by the Governor?
Answer:

1. Article 361 (1) provides the following privileges to the Governor.
2. The Governor of the state, is not answerable to any court for the exercise and performance of the powers and duties of his office.
3. No criminal proceedings what so ever shall be instituted or continued against the Governor of a state, in any court during his term of office.
4. No process for the arrest or imprisonment of the Governor of a state shall issue from any court during his term of office.
5. No civil proceedings in which relief is claimed against the Governor of the state.

Question 2.
How does a High Court keep control over the subordinate courts?
Answer:
A High, fourt has an administrative control over the subordinate Courts.
(i) It is consulted by the Governor in the matters of appointment, posting and promotions of District Judges and in appointments of persons to the judicial service of the State.

(ii) It deals with the matters of posting, promoting, grant of leave, transfers and discipline of . the members of the judicial services of the State.

(iii) It can withdraw a case pending in a subordinate court if it involves a substantial question of law that requires the interpretation of the Constitution. It can then either dispose of the case itself or determines the questions of law and return the case to the subordinate court with its judgement.

(iv) Its law is binding on all subordinate Courts functioning with its territorial jurisdiction in the same sense as the law declared by the Supreme Court is binding on all Courts in India.

Question 3.
Write about the Writs issued by the High Court?
Answer:
Under Article 226 of the constitution the High Courts are given powers of issuing writs. They are:

Habeas Corpus: It is issued to a detaining authority ordering the detainer to produce the detained person in the issuing court, along with the cause of his or her detention.

If the detention is found to be illegal, the court issues an order to set the person free.

Mandamus: It is issued to a Subordinate Court, an office or Government, or a Corporation or other Institution commanding the performance of certain acts or duties.

Prohibition: The writ of prohibition is issued by a higher court to a lower court prohibiting it from taking up a case because it is not under the jurisdiction of the lower court. Thus the higher court transfers the case to it. Quo Warranto: It is issued against a person the legality of holding a public office. Through this writ the court inquires “by what authority”? The person supports his / her claim.

Certiorari: This writ is issued to lower court directing that the record of a case be sent up for review, together with all supporting files, evidence and documents. It is one of the mechanism by which the fundamental rights of the citizens are upheld.

Question 4.
What are the works done by the High Court under supervisory Jurisdiction?
Answer:
The High Court has the power of superintendence over all Courts and Tribunals functioning in its Territorial Jurisdiction ( except the Military Courts or Tribunals).

Thus it may

1. Call for returns from them.
2. Make an issue, general rules and prescribe forms for regulating the practice and proceedings of them.
3. Prescribe forms in which books, entries and accounts are to be kept by them and
4. Settle the fee payable to the sheriff, clerks, officers and legal practitioners of them.

Students can download 10th Science Chapter 9 Solutions Questions and Answers, Notes, Samacheer Kalvi 10th Science 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 10th Science Solutions Chapter 9 Solutions

Samacheer Kalvi 10th Science Solutions Text Book Back Questions and Answers

I. Choose the best answer:

Question 1.
A solution is a mixture.
(a) homogeneous
(b) heterogeneous
(c) homogeneous and heterogeneous
(d) non-homogeneous
Answer:
(a) homogeneous

Question 2.
The number of components in a binary solution is ______.
(a) 2
(b) 3
(c) 4
(d) 5.
Answer:
(a) 2

Question 3.
Which of the following is the universal solvent?
(a) Acetone
(b) Benzene
(c) Water
(d) Alcohol
Answer:
(c) Water

Question 4.
A solution in which no more solute can be dissolved in a definite amount of solvent at a given temperature is called ______.
(a) Saturated solution
(b) Un saturated solution
(c) Supersaturated solution
(d) Dilute solution.
Answer:
(a) Saturated solution

Question 5.
Identify the non-aqueous solution.
(a) sodium chloride in water
(b) glucose in water
(c) copper sulphate in water
(d) sulphur in carbon-di-sulphide
Answer:
(d) sulphur in carbon-di-sulphide

Question 6.
When pressure is increased at a constant temperature the solubility of gases in liquid ______.
(a) No change
(b) increases
(c) decreases
(d) no reaction.
Answer:
(b) increases

Question 7.
Solubility of NaCl in 100 ml water is 36 g. If 25 g of salt is dissolved in 100 ml of water how much more salt is required for saturation:
(a) 12 g
(b) 11 g
(c) 16 g
(d) 20 g
Answer:
(b) 11 g

Question 8.
A 25% alcohol solution means ______.
(a) 25 ml of alcohol in. 100 ml of water
(b) 25 ml of alcohol in 25 ml of water
(c) 25 ml of alcohol in 75 ml of water
(d) 75 ml of alcohol in 25 ml of water.
Answer:
(c) 25 ml of alcohol in 75 ml of water

Question 9.
Deliquescence is due to:
(a) Strong affinity to water
(b) Less affinity to water
(c) Strong hatred to water
(d) Inertness to water
Answer:
(a) Strong affinity to water

Question 10.
Which of the following is hygroscopic in nature?
(a) ferric chloride
(b) copper sulphate pentahydrate
(c) silica gel
(d) none of the above.
Answer:
(c) silica gel

II. Fill in the blanks:

1. The component present in lesser amount, in a solution is called ……..
2. Example for liquid in solid type solution is ……….
3. Solubility is the amount of solute dissolved in ……… g of solvent.
4. Polar compounds are soluble in ……… solvents.
5. Volume percentage decreases with increases in temperature because ………

Answer:

1. solute
2. amalgam
3. 100
4. Polar
5. of expansion of liquid

III. Match the following:

Answer:
A. (iii)
B. (i)
C. (iv)
D. (ii)

IV. True or False: (If false give the correct statement):

1. Solutions which contain three components are called binary solution.
2. In a solution the component which is present in lesser amount is called solvent.
3. Sodium chloride dissolved in water forms a non-aqueous solution.
4. The molecular formula of green vitriol is MgSO₄. 7H₂O
5. When Silica gel is kept open, it absorbs moisture from the air, because it is hygroscopic in nature.

Answer:

1. False – Solutions which contain two components are called binary solution.
2. False – In a solution the component which is present in lesser amount is called solute.
3. False – Sodium chloride dissolved in water forms an aqueous solution.
4. False – The molecular formula of green vitriol is FeSO₄. 7H₂O
5. True

V. Short Answer Questions:

Question 1.
Define the term: Solution
Answer:
A solution is a homogeneous mixture of two or more substances.

Question 2.
What is mean by the binary solution?
Answer:
A solution must at least be consisting of two components. Such solutions which are made of one solute and one solvent are called binary solutions.
E.g., On adding CuSO₄ crystals to water.

Question 3.
Give an example each

1. gas in liquid;
2. solid in liquid;
3. solid in solid;
4. gas in gas.

Answer:

1. Gas in liquid – CO₂ in water
2. Solid in liquid – NaCl in water
3. Solid in solid – Alloys
4. Gas in gas – He – O₂ gas

Question 4.
What is the aqueous and non-aqueous solution? Give an example.
Answer:
Aqueous solution: The solution in which water act as a solvent is called aqueous solution. In general, ionic compounds are soluble in water and form aqueous solutions more readily than covalent compounds. E.g. Common salt in water.

Non – Aqueous solution: The solution in which any liquid, other than water act as a solvent is called non-aqueous solution. Alcohols, benzene, ethers, etc., are used as non – aqueous solvents. E.g. Sulphur dissolved in carbon disulphide.

Question 5.
Define Volume percentage.
Answer:
Volume percentage is defined as the percentage by volume of solute (in ml) present in the given volume of solution.

Question 6.
The aquatic animals live more in a cold region. Why?
Answer:
Aquatic animals live more in cold regions because the solubility of oxygen is more in cold water (at low temperature). Therefore, aquatic animals are more comfortable in cold water.

Question 7.
Define Hydrated salt.
Answer:
Ionic substances which crystallise out from their saturated aqueous solution with a definite number of molecules of water are called hydrated salts.

Question 8.
A hot saturated solution of copper sulphate forms crystals as it cools. Why?
Answer:
The capability of a solution to maintain a certain concentration of solute is temperature-dependent. When a saturated solution of copper sulphate at above room temperature is allowed to cool, the solution becomes supersaturated and in the absence of stirring or the return of the previous solution temperature, the solute starts to precipitate out. i.e., crystal formation occurs.

Question 9.
Classify the following substances into deliquescent, hygroscopic. Cone. Sulphuric acid, Copper sulphate penta hydrate, Silica gel, Calcium chloride and Gypsum salt.
Answer:

VI. Long answer questions:

Question 1.
Write notes on?

1. saturated solution
2. unsaturated solution

Answer:

1. Saturated solution: A solution in which no more solute can be dissolved in a definite amount of the solvent at a given temperature is called saturated solution, e.g. 36 g of sodium chloride in 100 g of water at 25°C forms a saturated solution.
2. Unsaturated solution: Unsaturated solution is one that contains less solute than that of the saturated solution at a given temperature, e.g. 10 g or 20 g or 30 g of Sodium chloride in 100 g of water at 25°C forms an unsaturated solution.

Question 2.
Write notes on various factors affecting solubility.
Answer:
There are three main factors which affects the solubility of a solute. They are

1. Nature of the solute and solvent
2. Temperature
3. Pressure

1. Nature of the solute and solvent : The nature of the solute and solvent plays an important role in solubility. Even though water is Universal solvent, all substances do not dissolve in water. Dissolution occurs when similarities exist between the solvent and the solute.

Ionic compounds are soluble in polar solvent like water and covalent compounds are soluble in non-polar solvents like ether, benzene, alcohol etc.

2. Effect of Temperature :
Solubility of solid in liquid : Generally solubility of a solid solute in a liquid increases with increase in temperature.
In Endothermic process : Solubility increases with increase in temperature.
In Exothermic process : Solubility decreases with increase in temperature.
Solubility of Gases in liquid : Solubility of gases in liquid decreases with increase in temperature.

3. Effect of Pressure : Effect of pressure is observed only in the case of solubility of a gas in a liquid. When the pressure is increased, the solubility of a gas in liquid increases.

Question 3.
(a) What happens when MgSO₄.7H₂O is heated? Write the appropriate equation
(b) Define solubility.
Answer:
(a) When Epsom salt MgSO₄.7H₂O crystals are gently heated, it loses seven water molecules and becomes anhydrous MgSO₄.

(b) Solubility is defined as the amount of solute in grams that can be dissolved in 100 g of the solvent to form its saturated solution at a given temperature and pressure.

Question 4.
In what way hygroscopic substances differ from deliquescent substances.
Answer:

Question 5.
A solution is prepared by dissolving 45 g of sugar in 180 g of water. Calculate the mass percentage of solute.
Answer:
Mass of the solute (sugar) = 45 g
Mass of the solvent (Water) = 180 g
Formula:
Mass percentage of solute (sugar)

The mass percentage of solute = 20%

Question 6.
3.5 litres of ethanol is present in 15 litres of aqueous solution of ethanol. Calculate volume percent of ethanol solution.
Answer:
Volume of ethanol = 3.5 lit = 3500 ml
Volume of water = 15 lit = 15000 ml
Formula:

The volume percentage of ethanol solution = 18.92

VII. HOT Questions

Question 1.
Vinu dissolves 50 g of sugar in 250 ml of hot water, Sarath dissolves 50 g of same sugar in 250 ml of cold water. Who will get a faster dissolution of sugar? and Why?
Answer:
Vinu will get a faster dissolution of sugar. Because generally solubility of a solid solute in a liquid solvent increases with increase in temperature. Therefore Vinu dissolves 50 g of sugar in 250 ml of hot water than Sarath dissolves 50 g of sugar in 250 ml of cold water.

Question 2.
‘A’ is a blue coloured crystalline salt. On heating it loses blue colour and to give ‘B’ When water is added, ‘B’ gives back to ‘A’. Identify A and B, write the equation.
Answer:
Since ‘A’ is a blue coloured crystalline salt, it is CuSO₄. 5H₂O (Blue vitriol). On heating it loses all five water molecules and becomes colourless anhydrous CuSO₄.

When water is added ‘B’ gives back A.

Question 3.
Will the cool drinks give more fizz at top of the hills or at the foot? Explain.
Answer:
At hilltops, the temperature will become less and pressure also decreases. Because temperature and pressure are directly proportional to each other. At low-pressure carbonate, cool drinks will give less fizz and give more fizz at the foot.

Samacheer Kalvi 10th Science Solutions Additional Important Questions and Answers

I. Choose the correct answer:

Question 1.
The dissolution of sugar and salt in water results in a solution.
(a) Binary
(b) Ternary
(c) Quaternary
(d) Saturated
Answer:
(b) Ternary

Question 2.
In a solution, the component which is present in a lesser amount is called ______.
(a) solvent
(b) dissolution
(c) solute
(d) mole.
Answer:
(c) solute

Question 3.
The supersaturated solution of NaCl in 100 g of water at 25°C contains:
(a) 40 g of NaCl
(b) 10 g of NaCl
(c) 20 g of NaCl
(d) 30 g of NaCl
Answer:
(a) 40 g of NaCl

Question 4.
How many component(s) present in binary solution?
(a) 1
(b) 2
(c) 3
(d) 4.
Answer:
(b) 2

Question 5.
Formalin is an aqueous solution of:
(a) formic acid
(b) ammonia
(c) formaldehyde
(d) carbon tetrachloride
Answer:
(c) formaldehyde

Question 6.
The effect of pressure on the solubility of a gas in liquids is given by:
(a) Boyle’s Law
(b) Charle’s Law
(c) Henry’s Law
(d) Avogadro’s Law
Answer:
(c) Henry’s Law

Question 7.
Which one of the following is an example of an aqueous solution?
(a) Sugar in water
(b) Sulphur in carbon disulphide
(c) Iodine dissolved in carbon tetrachloride
(d) Benzoic acid in ethers.
Answer:
(a) Sugar in water

Question 8.
The type of solution when CO₂ is dissolved in water:
(a) solid/liquid
(b) liquid in liquid
(c) gas in liquid
(d) liquid in solid
Answer:
(c) gas in liquid

Question 9.
Tin amalgam is an example of ……… solution.
(a) solid in solid
(b) liquid in solid
(c) solid in liquid
(d) liquid in liquid
Answer:
(b) liquid in solid

Question 10.
In which case solubility decreases with increase in temperature?
(a) Endothermic process
(b) Exothermic process
(c) Both (a) and (b)
(d) None of these.
Answer:
(b) Exothermic process

Question 11.
Fat is soluble in:
(a) water
(b) alcohol
(c) CCl₄
(d) ether
Answer:
(d) ether

Question 12.
The deliquescent substance among the following is:
(a) con.H₂SO₄
(b) P₂O₅
(c) CaCl₂
(d) SiO₂
Answer:
(c) CaCl₂

Question 13.
Mass percentage is expressed as ______.
(a) v/v
(b) w/w
(c) v/w
(d) w/v.
Answer:
(b) w/w

Question 14.
Hygroscopic substances are used as ……… agents.
(a) foaming
(b) drying
(c) oxidising
(d) reducing
Answer:
(b) drying

Question 15.
The molecular formula of Epsom salt is ______.
(a) CuSO₄.5H₂O
(b) FeSO₄.7H₂O
(c) MgSO₄.7H₂O
(d) ZnSO₄.7H₂O.
Answer:
(c) MgSO₄.7H₂O

II. Fill in the blanks:

1. A true solution is a ……… mixture of solute and solvent.
2. Soil cannot store more nitrogen than it can hold because soil is said to be in a state of ………
3. In the dissolution of NaOH in water, the solubility …….. with increase in temperature.
4. Aquatic animals are more comfortable in cold water because as the temperature is less the solubility of dissolved oxygen ………
5. Hydrated salts contain ……… of crystallization.
6. He-O₂ mixture is a binary solution of …….. in ………. solution.
7. The solvent used for dissolving Sulphur is ……….
8. The solubility of NaOH at 25°C is ……….
9. According to Henry’s Law, the solubility of a gas in liquid is ………. proportional to the pressure of the gas over the solution at definite temperature.
10. Anhydrous Calcium chloride is a ………. substance.
11. ……… substances absorb enough water from the atmosphere and get completely dissolved.
12. When 90g of sodium bromide is dissolved in 100 g of water at 25°C it forms a ………. solution.
13. ………. is an example of a binary solution with liquid in Gas.
14. Air and sea water are important ……… solution.
15. A quaternary solution contains ……….. components.
16. The primary factor which determines the characteristic of a solution is ………..
Answer:
1. Homogeneous
2. saturation
3. decreases
4. increases
5. water
6. Gas, Gas
7. CS₂ (or) Carbon disulphide
8. 80 g
9. directly
10. Hygroscopic
11. deliquescent
12. Unsaturated
13. Cloud
14. Homogeneous
15. four
16. Physical state

III. Match the following

Question 1.
Match the column I with column II.

Answer:
A. (iv)
B. (iii)
C. (v)
D. (ii)
E. (i)

Question 2.
Match the column I with column II.

Answer:
A. (iii)
B. (iv)
C. (v)
D. (ii)
E. (i)

Question 3.
Match the column I with column II.

Answer:
A. (v)
B. (iii)
C. (ii)
D. (i)
E. (iv)

Question 4.
Match the column I with column II.

Answer:
A. (iii)
B. (iv)
C. (v)
D. (i)
E. (ii)

Question 5.
Match the column I with column II.

Answer:
A. (iv)
B. (iii)
C. (i)
D. (v)
E. (ii)

IV. True or False: (If false give the correct statement)

1. In an aqueous solution of copper sulphate, the solvent is copper sulphate.
2. A solution containing sugar and salt in water is a binary solution.
3. An example of a solid solution is alloy.
4. The difference between concentrated and dilute solution can be observed by means of colour (or) density.
5. A saturated solution contains 91 g of Glucose in 100 g of water at 25°C.
6. Fat is dissolved in the aqueous solvent ether.
7. The solubility of a gas in a liquid is inversely proportional to the pressure of the gas at a definite temperature.
8. Mass percentage of a solution is expressed as .
9. The white vitriol is represented by the formula ZnSO₄ . 7H₂O.
10. Ferric chloride is a Hygroscopic substance.
Answer:
1. False – In an aqueous solution of copper sulphate, the solvent is water.
2. False – A solution containing sugar and salt in water is a ternary solution.
3. True
4. True
5. True
6. False – Fat is dissolved in the non-aqueous solvent ether.
7. False – The solubility of a gas in a liquid is directly proportional to the pressure of the gas at a definite temperature.
8. True
9. True
10. False – Ferric chloride is a deliquescent substance.

V. Short answer questions:

Question 1.
(i) Which gas is dissolved in soft drinks?
(ii) What will you do to increase the solubility of this gas?
Answer:
(i) Carbon-di-oxide (CO₂) is dissolved in soft drinks.
(ii) An increase in pressure will increase the solubility of CO₂ gas.

Question 2.
Identify the type of binary solution given below.
Answer:

1. Alloys
2. Amalgam
3. Ethyl alcohol in water
4. Aerated drinks

Answer:

1. Solid in solid
2. liquid in solid
3. liquid in liquid
4. Gas in liquid

Question 3.
Explain why Nitrogen in soil is called a saturated solution in nature?
Answer:
Nitrogen in soil is an example of a saturated solution in nature. Soil cannot store more Nitrogen than it can hold.

Question 4.
Define Mass percentage.
Answer:
Mass percentage of a solution is defined as the percentage by mass of the solute present in the solution.

Question 5.
Define the term Molarity (M).
Answer:

Question 6.
Define the term Molality (m).
Answer:

Question 7.
Define the supersaturated solution.
Answer:
A supersaturated solution is one that contains more solute than the saturated solution at a given temperature.
E.g. 40 g of sodium chloride in 100 g of water at 25°C.

Question 8.
Justify the following statements with an explanation.
(i) Solubility of NH₄Cl increases with increase in temperature.
Answer:
Solubility of NH₄Cl increases with increase in temperature because it is an endothermic process.

(ii) Solubility of NaOH decreases with increase in temperature.
Answer:
Solubility of NaOH decreases with increase in temperature because it is an exothermic process.

Question 9.
Calculate the molarity of a solution containing 4 g of NaOH in 500 ml of water.
Answer:
Mass of NaOH = 4 g
Volume of solution = 500 ml

= 0.1 × 2
= 0.2 M

Question 10.
Calculate the molality of a solution containing 3 g of urea (molecular mass = 60) in 750 g of water.
Answer:
Mass of urea (solute) = 3 g
Mass of water (solvent) = 750 g
Formula:

Question 11.
Define dissolution.
Answer:
The process of uniform distribution of solute into solvent is called dissolution.

VI. Long answer questions:

Question 1.
Answer the blanks given in the table.
Answer:

Question 2.
Write a note on the type of solution based on the type of solvent.
Answer:
(i) Aqueous solution : The solution in which water acts as a solvent is called aqueous solution. In general, ionic compounds are soluble in water and form aqueous solutions more readily than covalent compounds.
Eg: Common salt in water, Sugar in water, Copper sulphate in water etc..

(ii) Non-Aqueous solution : The solution in which any liquid, otter than water, acts as a solvent is called non-aqueous solution. Solvent other than water is referred to as non-aqueous solvent. Generally, alcohols, benzene, ethers, carbon disulphide, acetone, etc., are used as non- aqueous solvents.
Eg: Sulphur dissolved in carbon disulphide, Iodine dissolved in carbon tetrachloride.

Question 3.
Justify the following statements with an explanation.

1. The solubility of calcium oxide decreases with increase in temperature,
2. What happens to the solubility in the exothermic process with regard to temperature?
3. In the endothermic process, solubility increases with increase in temperature.
4. At a given temperature, an increase in pressure increases the solubility of the gas

Answer:

1. In an exothermic process, the solubility decreases. When calcium oxide dissolves in water, an exothermic reaction takes place, and so the solubility of calcium oxide decreases
2. In an exothermic process, the solubility decreases with the increase in temperature, as there is already an evolution of heat and it is observed.
3. In an endothermic process, the solubility increases. The solubility of KNO₃ in water is an endothermic reaction and so solubility increases with the increase of temperature.
4. At a given temperature, an increase in pressure increases the solubility of gas according to Henry’s law. e.g. (CO₂ in soft drinks)

VII. Hot Questions.

Question 1.
50 ml tincture of benzoin, antiseptic solution contains 10 ml of benzoin. Calculate the volume of percentage of benzoin.
Answer:
Volume of the solute, Benzoin = 10 ml
Volume of the solution, tincture of benzoin = 50 ml

= 20% (v/v)

Question 2.
Neomycin, the antibiotic cream contains 300 mg of neomycin sulphate the active ingredient in 30 g of ointment base. Calculate the mass percentage of neomycin.
Answer:
Mass of neomycin sulphate(solute) = 300 mg
Mass of the ointment (solution) = 30 g
Formula:

VIII. Numerical problems:

Question 1.
Calculate the molality of the solution containing 18 g of Glucose (Molecular mass 180) in 2 kg of water.
Answer:
Mass of Glucose = 18 g
Molecular mass of Glucose = 180

= 0. 05 m

Question 2.
Calculate the molarity of a solution containing 5.85 g of sodium chloride in 500 ml of the water. (Molecular mass = 58.5)
Answer:
Mass of the solute = 5.85 g
Volume of the solution = 500
No. of moles of NaCl = \(\frac{5.85}{58.5}\) = 0.1

= \(\frac{0.1}{500}\) × 1000 = 0.2 M

Students can download 10th Science Chapter 13 Structural Organisation of Animals Questions and Answers, Notes, Samacheer Kalvi 10th Science 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 10th Science Solutions Chapter 13 Structural Organisation of Animals

Samacheer Kalvi 10th Science Structural Organisation of Animals Text Book Back Questions and Answers

I. Choose the best answer:

Question 1.
In leech locomotion is performed by:
(a) Anterior sucker
(b) Posterior sucker
(c) Setae
(d) None of the above
Answer:
(a) Anterior sucker

Question 2.
The segments of leech are known as _____.
(a) Metameres (somites)
(b) Proglottids
(c) Strobila
(d) All the above.
Answer:
(a) Metameres (somites).

Question 3.
Pharyngeal ganglion in leech is a part of:
(a) Excretory system
(b) Nervous system
(c) Reproductive system
(d) Respiratory system
Answer:
(b) Nervous system

Question 4.
The brain of leech lies above, the _____.
(a) Mouth
(b) Buccal Cavity
(c) Pharynx
(d) Crop.
Answer:
(c) Pharynx

Question 5.
The body of leech has:
(a) 23 segments
(b) 33 segments
(c) 38 segments
(d) 30 segments
Answer:
(b) 33 segments

Question 6.
Mammals are animals.
(a) Cold blooded
(b) Warm blooded
(c) Poikilothermic
(d) All the above
Answer:
(b) Warm blooded

Question 7.
The animals which give birth to young ones are _____.
(a) Oviparous
(b) Viviparous
(c) Ovoviviparous
(d) All the above.
Answer:
(d) All the above

II. Fill in the blanks:

1. The posterior sucker is formed by the fusion of the ………. segments.
2. The existence of two sets of teeth in the life of an animal is called ……….. dentition.
3. The anterior end of leech has a lobe-like structure called ………..
4. The blood sucking habit of leech is known as ………..
5. ………. separate nitrogenous waste from the blood in rabbit.
6. ……… spinal nerves are present in rabbit.

Answer:

1. last seven
2. diphyodont
3. anterior sucker
4. sanguivorous
5. Nephrons (kidney)
6. 37 pair

III. Identify whether the statements are True or False. Correct the false statement:

1. An anticoagulant present in saliva of leech is called heparin.
2. The vas deferens serves to transport the ovum.
3. The rabbit has a third eyelid called tympanic membrane which is movable.
4. Diastema is a gap between premolar and molar teeth in rabbit.
5. The cerebral hemispheres of rabbit are connected by band of nerve tissue called corpora quadrigemina.

Answer:

1. True
2. False – Vas deferens serves to transport the sperm.
3. True
4. False – The gap between the incisors and premolars.
5. False – The cerebral hemispheres of rabbit are connected by band of nerve tissue called corpora corpus callosum.

IV. Match columns I, II and III correctly:

Answer:

V. Answer in a sentence:

Question 1.
Give the common name of the Hirudinaria granulosa.
Answer:
The common name of Hirundinaria granulosa is Indian Cattle Leech.

Question 2.
How does leech respire?
Answer:
Leech respire through the skin.

Question 3.
Write the dental formula of rabbit.
Answer:
The dental formula of rabbit is \(\frac{2033}{1023}\)

Question 4.
How many pairs of testes are present in leech?
Answer:
There are 11 pairs of testes are present in Leech.

Question 5.
How is diastema formed in rabbit?
Answer:
Diastema is due to the absence of canine. It is a gap between incisors and premolars in the upper jaw and lower jaw.

Question 6.
What organs are attached to the two bronchi?
Answer:
The organs attached to the two bronchi are lungs.

Question 7.
Which organ acts as a suction pump in leech?
Answer:
The Pharynx acts as a suction pump in Leech.

Question 8.
What does CNS stand for?
Answer:
The full form of CNS is Central Nervous System.

Question 9.
Why is the teeth of rabbit called heterodont?
Answer:
The dentition of rabbit is called heterodont, as they have different types of teeth (Incisors, premolars and molars).

Question 10.
How does leech suck blood from the host?
Answer:
The Anterior sucker helps in feeding, while both the suckers, help in attachment and locomotion.

VI. Short answer questions:

Question 1.
Why are the rings of cartilages found in trachea of rabbit?
Answer:
The wall of larynx which serves as the voice box is supported by 4 cartilaginous plates. When the air passes the vocal cord, it vibrates resulting in sound production.

Question 2.
List out the parasitic adaptations in the leech.
Answer:
Leeches lead a parasitic mode of life, by sucking the blood of vertebrates. The adaptations are

• Blood is sucked by the pharynx.
• Anterior and Posterior Suckers are provided, by which the animal attaches itself to the body of the host.
• The three Jaws, inside the mouth, causes a painless Y – shaped wound in the skin of the host,
• The salivary glands produce Hirudin, which does not allow the blood to coagulate. So, the continuous supply of blood is maintained.
• Parapodia and Setae are absent.
• Blood is stored in the crop. It gives nourishment to the leech for several months. So there is no elaborate secretion of the digestive juices and enzymes.

VII. Long answer questions:

Question 1.
How is the circulatory system designed in leech to compensate the heart structure?
Answer:
The circulation in Leech is Haemocoelic system. There are no true blood vessels. The blood vessels are replaced by channels called Haemocoelic channels or canals, filled with blood like a fluid. The coelomic fluid contains Haemoglobin.

There are four longitudinal channels. One channel lies above (dorsal) to the Alimentary canal, one below (ventral) to the Alimentary canal. The other two channels lie on either (lateral) side of the Alimentary canal, which serves as a heart and have inner valves. All the four channels are connected together posteriorly in the 26th segment. Thus the circulatory system is designed in Leech to compensate the heart structure.

Question 2.
How does locomotion take place in leech?
Answer:

1. Looping or Crawling movement : Looping movement is brought about by the contraction and relaxation of muscles. The two suckers serve for attachment during movement. The animal fixes its posterior sucker on the substratum.
2. Swimming movement : The animal swims in the water by undulating movements of the body.

Question 3.
Explain the male reproductive system of rabbit with a labelled diagram.
Answer:
The male rabbit has a pair of testes. They are oval in shape. They are kept in two sacs called scrotal sacs hanging down from the abdomen. Each testes is formed of numerous fine tubules called seminiferous tubules. A coiled tubule called epididymis is formed at the end of seminiferous tubules. Epididymis lead into the sperm duct called vas deferens. The vas deferens run forward and enters abdominal cavity through urinary bladder. The urethra runs back and passes into the penis. There are three accessory glands associated with the male reproductive system. They are prostate glands, cowper’s gland and perineal glands. Their secretion nourishes and activates the reproduction.

VIII. Higher Order Thinking Skills (HOTS).

Question 1.
Arjun is studying in the tenth standard. He was down with fever and went to meet the doctor. As he went to the clinic he saw a patient undergoing treatment for severe leech bite. Being curious, Arjun asked the doctor why leech bite was not felt as soon as it attaches to the skin? What would have been the reply given by the doctor?
Answer:
The doctors would have replied that the leeches inject an anaesthetic substance, that prevents the host from feeling their bite.

Question 2.
Shylesh has some pet animals at his home. He has few rabbits too, one day while feeding them he observed something different with the teeth. He asked his grandfather, why is it so? What would have been the explanation of his grandfather?
Answer:
The rabbit has three types of teeth – Incisors are front teeth used for cutting, premolar and molar are used for grinding. Canine is absent as rabbit are herbivores. The gap between the incisor and premolar is called diastema. It helps in mastication and chewing of food in herbivores animal.

IX. Value-Based Questions:

Question 1.
Leeches do not have an elaborate secretion of digestive juices and enzymes. Why?
Answer:
The digestion in leeches in very slow. So, the blood stored in the crop gives nourishment to the leech for several months. So there is not elaborate secretion of digestive juices and enzymes.

Question 2.
How is the digestive system of rabbit suited for herbivorous mode of feeding?
Answer:
Rabbit are herbivores which feed on plants. The plant contain cellulose which need cellulose to digest. The laccum of Rabbit contain large number of symbiotic bacteria that helps in digestion of cellulose.

Samacheer Kalvi 10th Science Structural Organisation of Animals Additional Important Questions and Answers

I. Choose the correct answer:

Question 1.
(a) Vas deferens and Epididymis
(b) Ovary and Caeca
(c) Hirudin and Stomach
(d) Nephridia and Papillae.
Answer:
(a) Vas deferens and Epididymis

Question 2.
Diastema is:
(a) A part of pelvic girdle in rabbit
(b) A type of tooth in rabbit
(c) Space in teeth line in mammals
(d) Structure in eye of rabbit
Answer:
(c) Space in teeth line in mammals

Question 3.
(a) Suckers and Mammary glands
(b) Cowper’s gland and Perineal gland
(c) Forebrain and Oesophagus
(d) Cellulose and Colouration.
Answer:
(b) Cowper’s gland and Perineal gland

Question 4.
If the dental formula of rabbit is \(\frac{2023}{1023}\) What does it show?
(a) Total number of teeth in Rabbit is 15
(b) Number of total incisors in Rabbit is 3
(c) Diastema is present between incisors and premolars
(d) In the formula 2033 is for adult and 1023 is for young ones
Answer:
(c) Diastema is present between incisors and premolars

Question 5.
Number of pairs of salivary glands present in Rabbit is:
(a) one
(b) three
(c) four
(d) five
Answer:
(c) four

Question 6.
Number of Vertebrae in rabbit is:
(a) 44 – 47
(b) 40 – 44
(c) 42 – 48
(d) 47 – 50
Answer:
(a) 44 – 47

Question 7.
If the diaphragm of a rabbit is perforated breathing is:
(a) Not affected
(b) Increased
(c) Decreased
(d) Stopped
Answer:
(d) Stopped

Question 8.
Tracheal rings in rabbit are:
(a) complete
(b) dorsally incomplete
(c) lateral incomplete
(d) incomplete
Answer:
(b) dorsally incomplete

Question 9.
Which one of the following is not a characteristic of leech?
(a) closed circulatory system
(b) segmentation
(c) pseudo coelom
(d) ventral nerve cord
Answer:
(c) pseudo coelom

Question 10.
The blood vascular system, of rabbit is:
(a) open type
(b) closed type
(c) semi closed type
(d) semi open type
Answer:
(b) closed type

Question 11.
The wall of Rabbit’s heart is thick due to the presence of:
(a) Inner layer endocardium
(b) Middle layer myocardium
(c) Outer layer pericardium
(d) Outer layer epicardium
Answer:
(b) Middle layer myocardium

Question 12.
Leech belongs to the class:
(a) polychaeta
(b) oligochaeta
(c) hirundinea
(d) archiannelida
Answer:
(c) hirundinea

Question 13.
A temporary clitellum occur during the breeding season in:
(a) Pheretima
(b) Heteroneris
(c) Hirundinaria
(d) Aphrodile
Answer:
(c) Hirundinaria

Question 14.
Saliva of leeches contains an anti coagulation called:
(a) Heparin
(b) Histamine
(c) Hirudin
(d) Haematin
Answer:
(c) Hirudin

II. Fill in the blanks:

1. Hirudinaria granulosa belong to the phylum ……..
2. The scientific name of the rabbit is ………
3. ………. is the segmentation of the body.
4. The type of movement is brought by the contraction and relaxation of muscles in leeches is ………
5. In leech, the digestion takes place in stomach by the action of …………
6. The ……….. prevents the entry of food into the trachea through the glottis.
7. The existence of two sets of teeth in the life of an animal is called ………… dentition.
8. ……….. contains bacteria that helps in digestion of cellulose.
9. The anterior part of the oviduct in rabbit is …………
10. Breathing movement in mammals are brought by ………..
Answer:
1. Annelida
2. Oryctolagus cuniculus
3. Metamerism
4. Looping or crawling movement
5. Proteolytic enzyme
6. Epiglottis
7. Diphyodont
8. Caecum
9. Fallopian tube
10. Diaphragm

III. Identify whether the statements are True or False. Correct the false statement:

1. Mammary gland in male is the most striking feature of mammals.
2. The leech makes a triradiate or y-shaped incision in the skin of the host by the joins protrude through the mouth.
3. Crop and its diverticular in leech can store large amount of blood which can be slowly digested.
4. Breathing movement in Rabbit are brought by the movement of vibrissae.
5. In rabbit pair of cowper’s gland and perineal gland are present only in the male.

Answer:

1. False – Mammary gland in female is the most striking feature of mammals.
2. True
3. True
4. False – Breathing movement in Rabbit are brought by Diaphragm
5. False – In rabbit pair of cowper’s gland and perineal gland are present both male and female

IV. Match the following:

Answer:
A. (v)
B. (i)
C. (ii)
D. (iii)
E. (iv)

V. Answer in a sentence:

Question 1.
Name the excretory organ of leech.
Answer:
Excretion in leech takes place by nephridia.

Question 2.
Give the Scientific name of Rabbit.
Answer:
Oryctolagus Cuniculus.

Question 3.
Where is the brain of rabbit located?
Answer:
The brain of rabbit is located in the cranial cavity and covered by three membrane of duramater, piamater and arachnoid membrane.

Question 4.
How many pairs of cranial nerves are there in the Peripheral Nervous System?
Answer:
12 pairs of cranial nerves.

Question 5.
What is other name of whiskers in rabbit?
Answer:
The sides of the upper lip produce stiff long thick hairs called vibrissae or whisker which are tactile sensory organ.

Question 6.
Which type of rabbit are endangered species?
Answer:
Pygmy Rabbits are listed as an endangered species.

Question 7.
Name the existence of two sets of teeth in the life of an animal.
Answer:
Diphyodont dentition

Question 8.
Why Rabbits are called gregarious animals?
Answer:
Rabbits are called gregarious animals as they move in group.

Question 9.
Which animals are called sanguivorous?
Answer:
Blood sucking animals.

Question 10.
What are nephridropores?
Answer:
In leech, excretion takes place by segmentally arranged paired tubules called nephridia. There are 17 pairs of nephridia which open by nephridiopores from 6th to 22nd segment.

VI. Short Answer Questions:

Question 1.
Write the systematic position of Indian Cattle Leech.
Answer:

Question 2.
What do you know about the Trunk of Rabbit?
Answer:
The trunk is divisible into an anterior thorax and a posterior abdomen. In females, four or five teats or nipples are present on the ventral surface between Thorax and abdomen. The trunk has two pairs of Pentadactyl limbs. The forelimbs are shorter than the hind limbs.

All the digits bear claws. The anus is present at the posterior end. In females, on the ventral side, a slit-like Vulva is present. In males, the Penis is present in the ventral side of Anus. The male has a pair of testes, enclosed by Scrotal Sacs.

Question 3.
How do the leeches respire?
Answer:
There is no special respiration organ in leech. The skin serves as a respiratory i organ. The capillaries containing the haemocoelomic fluid extend in between the cells of the epidermis, acts as a permeable membrane through which the exchange of gases takes place by diffusion.

Question 4.
What are diphyodont dentition and Heterodont dentition?
Answer:
The existence of two sets of teeth in the life of an animal is called diphyodont dentition. The two types of teeth are Milk teeth (Young ones) and Permanent teeth (in adults).

The different types of dentition are called Heterodont. There are four kinds of teeth in mammals.
The incisors (I), Canines (C), Premolars (PM) and Molars (M).

Question 5.
List out the five layers of body wall of Leech.
Answer:
The body wall of leech consists of five layers.

1. Cuticle
2. Epidermis
3. Dermis
4. Muscular layer and
5. Botryoidal tissue

Question 6.
Give the systematic position of Rabbit.
Answer:

Question 7.
Explain the Respiratory system of Leech.
Answer:
Respiration takes place through the skin in Leech. Dense, network to tiny blood vessels called Capillaries, containing haemocoel fluid extend, in between the cells of the epidermis. The exchange of respiratory gases takes place by diffusion. Oxygen dissolved in water diffuses through the skin, into haemocoel fluid, while Carbon dioxide, diffuses out. The skin is kept moist and slimy, due to the secretion of mucus, which prevents the skin from drying.

Question 8.
List out the steps involved in Inspiration in Rabbit.
Answer:
During Inspiration the atmospheric air takes the following route.

VII. Long answer questions:

Question 1.
Compare the digestive system of Leech and Rabbit.
Answer:

Question 2.
Short notes on the Nervous System of Leech.
Answer:
The Central Nervous System of Leech consists of a nerve ring and a paired ventral nerve cord. The nerve ring surrounds the Pharynx and is formed of Suprapharyngeal ganglion (brain), Circum pharyngeal connective and Subpharyngeal ganglion. The Subpharyngeal ganglion lies below the Pharynx and is formed by the fusion of four pairs of Ganglia.

Students can download 10th Science Chapter 10 Types of Chemical Reactions Questions and Answers, Notes, Samacheer Kalvi 10th Science 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 10th Science Solutions Chapter 10 Types of Chemical Reactions

Samacheer Kalvi 10th Science Types of Chemical Reactions Text Book Back Questions and Answers

I. Choose the correct answer:

Question 1
H_2(g) + Cl_29(g) → 2HCl_(g)
(a) Decomposition Reaction
(b) Combination Reaction
(c) Single Displacement Reaction
(d) Double Displacement Reaction
Answer:
(a) Decomposition Reaction

Question 2.
Photolysis is a decomposition reaction caused by ______.
(a) heat
(b) electricity
(c) light
(d) mechanical energy
Answer:.
(c) light
Hint:
\(2 \mathrm{AgBr}_{(\mathrm{s})} \stackrel{\mathrm{Light}}{\longrightarrow} 2 \mathrm{Ag}_{(\mathrm{s})}+\mathrm{Br}_{2(\mathrm{g})}\)

Question 3.
A reaction between carbon and oxygen is represented by C_(s) + O_2(g) → CO_2(g) + Heat. In which of the type(s), the above reaction can be classified?
(i) Combination Reaction
(ii) Combustion Reaction
(iii) Decomposition Reaction
(iv) Irreversible Reaction
(a) (i) and (ii)
(b) (i) and (iv)
(c) (i), (ii) and (iii)
(d) (i), (ii) and (iv)
Answer:
(d) (i), (ii) and (iv)

Question 4.
The chemical equation \(\mathrm{Na}_{2} \mathrm{SO}_{4(\mathrm{aq})}+\mathrm{BaCl}_{2(\mathrm{aq})} \rightarrow \mathrm{BaSO}_{4(\mathrm{s})} \downarrow+2 \mathrm{NaCl}_{(\mathrm{aq})}\) represents which of the following types of reaction?
(a) Neutralisation
(b) Combustion
(c) Precipitation
(d) Single displacement.
Answer:
(c) Precipitation
Hint: This reaction involves the precipitation of white BaSO₄ by mixing of Na₂SO₄ (aq) and BaCl₂ (aq). Hence it belongs to precipitation reaction.

Question 5.
Which of the following statements are correct about a chemical equilibrium?
(i) It is dynamic in nature
(ii) The rate of the forward and backward reactions are equal at equilibrium
(iii) Irreversible reactions do not attain chemical equilibrium
(iv) The concentration of reactants and products may be different
(a) (i), (ii) and (iii)
(b) (i), (ii) and (iv)
(c) (ii), (iii) and (iv)
(d) (i), (iii) and (iv)
Answer:
(a) (i), (ii) and (iii)

Question 6.
A single displacement reaction is represented by \(\mathrm{X}_{(\mathrm{s})}+2 \mathrm{HCl}_{(\mathrm{aq})} \rightarrow \mathrm{XCl}_{2(\mathrm{aq})}+\mathrm{H}_{2(\mathrm{g})}\). the following(s) could be X?
(i) Zn
(ii) Ag
(iii) Cu
(iv) Mg.
Choose the best pair.
(a) i and ii
(b) ii and iii
(c) iii and iv
(d) i and iv.
Answer:
(d) i and iv.
Hint:
Zn + 2HCl → ZnCl₂ + H₂
Mg + 2HCl → MgCl₂ + H_2.

Question 7.
Which of the following is not an “element + element → compound” type reaction?
(a) C_(s) + O_2(g) → CO_2(g)
(b) 2K_(s) + Br_2(l) → 2KBr_(s)
(c) 2CO_(g) + O_2(g) → 2CO_2(g)
(d) 4Fe_(s) + 3O_2(g) → 2Fe₂O_3(s)
Answer:
(c) 2CO_(g) + O_2(g) → 2CO_2(g)

Question 8.
Which of the following represents a precipitation reaction?
(a) A_(s) + B_(s) → C_(s) + D_(s)
(b) A_(s) + B_(aq) → C_(aq) + D_(l)
(c) A_(aq) + B_(aq) → C_(s) + D_(aq)
(d) A_(aq) + B_(s) → C_(aq) + D_(l)
Answer:
(c) A_(aq) + B_(aq) → C_(s) + D_(aq)

Question 9.
The pH of a solution is 3. Its [OH^–] concentration is ______.
(a) 1 × 10^-3 M
(b) 3 M
(c) 1 × 10^-11 M
(d) 11 M.
Answer:
(c) 1 × 10^-11 M
Hint: pH = 3
It means [H⁺] = 10^-3
[H⁺] [OH^–] = 10^-14
[10^-3] [OH^–] = 10^-14
[OH^–] = 10^-11

Question 10.
Powdered CaCO₃ reacts more rapidly than flaky CaCO₃ because of :
(a) large surface area
(b) high pressure
(c) high concentration
(d) high temperature
Answer:
(a) large surface area

II. Fill in the blanks:

1. A reaction between an acid and a base is called ………..
2. When zinc metal is placed in hydrochloric acid, ………. gas is evolved.
3. The equilibrium attained during the meiting of ice is known as ………..
4. The pH of a fruit juice is 5.6. If you add slaked lime to this juice, its pH ……….
5. The value of ionic product of water at 25 °C is ………..
6. The normal pH of human blood is …………
7. Electrolysis is type of ……….. reaction.
8. The number of products formed in a synthesis reaction is ………..
9. Chemical volcano is an example for ……….. type of reaction.
10. The ion formed by dissolution of H⁺ in water is called …………
Answer:
1. neutralization
2. H₂
3. physical equilibrium
4. increases to ‘7’
5. 1 × 10^-14 mol² dm^-6
6. 7.4
7. decomposition
8. 1
9. decomposition
10. hydronium ion

III. Match the following:

Question 1.
Identify the types of reaction:

Answer:
A. (iii)
B. (i)
C. (iv)
D. (ii)

IV. True or False: (If false give the correct statement)

1. Silver metal can replace hydrogen gas from nitric acid.
2. The pH of rain water containing dissolved gases like SO₃, CO₂, NO₂ will be less than 7.
3. At the equilibrium of a reversible reaction, the concentration of the reactants and the products will be equal.
4. Periodical removal of one of the products of a reversible reaction increases the yield.
5. On dipping a pH paper in a solution, it turns into yellow. Then the solution is basic.

Answer:

1. False – Silver cannot displace H₂ from HNO₃ acid, since it is placed below hydrogen in the activity series.
2. True
3. False – At equilibrium the concentration of the reactants and products do not change it remains constant, but the concentration of the reactants and the products will not be equal.
4. True
5. False – The solution is neutral if the solution is basic it will be green in colour.

V. Short answer questions:

Question 1.
When an aqueous solution of potassium chloride is added to an aqueous solution of silver nitrate, a white precipitate is formed. Give the chemical equation of this reaction.
Answer:

Question 2.
Why does the reaction rate of a reaction increase in raising the temperature?
Answer:
On increasing temperature heat is supplied to the reactant. This energy breaks more bonds and thus speed up the chemical reaction. Foods kept at room temperature spoils faster than that kept in the refrigerator.

Question 3.
Define combination reaction. Give one example for an exothermic combination reaction.
Answer:
A combination reaction is a reaction in which two or more reactants combine to form a compound.
Eg: C_(s) + O_2(g) → CO_2(g) + heat

Question 4.
Differentiate reversible and irreversible reactions.
Answer:

VI. Answer in detail:

Question 1.
What are called thermolysis reactions?
Answer:
Thermal decomposition reactions are called ‘thermolysis’ reaction. In this type of reaction, the reactant is decomposed by applying heat. There are two types of thermolysis reactions. They are:
(i) Compound to element / element decomposition:
A compound is decomposed into two elements.
Eg:

(ii) Compound to compound / compound decomposition:
A compound is decomposed into two compounds.
Eg:

Question 2.
Explain the types of double displacement reactions with examples.
Answer:
There are two major classes of double displacement reactions. They are,
(i) Precipitation Reactions: When aqueous solutions of two compounds are mixed, if they react to form an insoluble compound and a soluble compound, then it is called precipitation reaction.
\(\mathrm{Pb}\left(\mathrm{NO}_{3}\right)_{2(\mathrm{aq})}+2 \mathrm{KI}_{(\mathrm{aq})} \rightarrow \mathrm{PbI}_{2(\mathrm{s})} \downarrow+2 \mathrm{KNO}_{3(\mathrm{aq})}\)

(ii) Neutralisation Reactions: Another type of displacement reaction in which the acid reacts with the base to form a salt and water. It is called ‘neutralisation reaction’ as both acid and base neutralize each other.
\(\mathrm{NaOH}_{(\mathrm{aq})}+\mathrm{HCl}_{(\mathrm{aq})} \rightarrow \mathrm{NaCl}_{(\mathrm{aq})}+\mathrm{H}_{2} \mathrm{O}_{(\mathrm{l})}\).

Question 3.
Explain the factors influencing the rate of a reaction.
Answer:
Important factors that affect rate of a reaction are:

1. Nature of the reactants
2. Concentration of the reactants
3. Temperature
4. Catalyst
5. Pressure
6. Surface area of the reactants

1. Nature of the reactants : The reaction of sodium with hydrochloric acid is faster than that with acetic acid, because Hydrochloric acid is a stronger acid than acetic acid and thus more reactive. So, the nature of the reactants influence the reaction rate.
2Na_(s) + 2HCl_(aq) → 2NaCl_(aq) + H_2(g) (fast)
2Na_(s) + 2CH₃COOH_(aq) → 2CH₃COONa_(aq) + H_2(g) (slow)

2. Concentration of the reactants : Changing the amount of the reactants also increases the reaction rate. More the concentration, more particles per volume exist in it and hence faster the reaction. Granulated zinc reacts faster with 2M hydrochloric acid than 1M hydrochloric acid.

3. Temperature : Most of the reactions go faster at higher temperature. Because adding heat to the reactants provides energy to break more bonds and thus speed up the reaction. Calcium carbonate reacts slowly with hydrochloric acid at room temperature. When the reaction mixture is heated the reaction rate increases.

4. Pressure : If the reactants are gases, increasing their pressure increases the reaction rate. This is because, on increasing the pressure the reacting particles come closer and collide frequently.

5. Catalyst : A catalyst is a substance which increases the reaction rate without being consumed in the reaction. In certain reactions, adding a substance as catalyst speeds up the reaction. For example, on heating potassium chlorate, it decomposes into potassium chloride and oxygen gas, but at a slower rate. If manganese dioxide is added, it increases the reaction rate.

6. Surface area of the reactants : Powdered calcium carbonate reacts more readily with hydrochloric acid than marble chips. Because, powdering of the reactants increases the surface area and more energy is available on collision of the reactant particles. Thus, the reaction rate is increased.

Question 4.
How does pH play an important role in everyday life?
Answer:

• The pH of blood is almost 7.4. Any increase or decrease in this value leads to diseases
• Citrus fruits require slightly alkaline soil, while rice requires acidic soil and sugarcane requires neutral soil.
• If the pH of rainwater becomes less than 7, it becomes acid rain which is harmful in day-to-day life.
• pH changes cause tooth decay.
• During indigestion, the stomach produces too much acid and this causes pain and irritation.

Question 5.
What is chemical equilibrium? What are its characteristics?
Answer:
Chemical equilibrium is a state of a reversible chemical reaction where the,
Rate of forward reaction = Rate of backward reaction.
No change in the amount of the reactants and products takes place.
Characteristics of equilibrium:

1. In a chemical equilibrium, the rates of the forward and backward reactions are equal.
2. The observable properties such as pressure, concentration, colour, density, viscosity etc., of the system remain unchanged with time.
3. The chemical equilibrium is a dynamic equilibrium, because both the forward and backward reactions continue to occur even though it appears static externally.
4. In physical equilibrium, the volume of all the phases remain constant.

VII. HOT Questions:

Question 1.
A solid compound ‘A’ decomposes on heating into ‘B’ and a gas ‘C’ On passing the gas ‘C’ through water, it becomes acidic. Identify A, B and C.
Answer:
A – CaCO₃, solid compound
‘A’ decomposes on heating into ‘B’ and a gas ‘C’.

On passing the gas CO₂ through water, it becomes acidic.

A – CaCO₃, Calcium carbonate
B – CaO, Calcium oxide
C – CO₂, Carbondioxide gas

Question 2.
Can a nickel spatula be used to stir copper sulphate solution? Justify your answer.
Answer:
No, nickel spatula cannot be used to stir the copper sulphate solution. Actually, on the basis of activity series, nickel is more reactive than copper, so nickel will displace copper from its solution and copper will be deposited on nickel spatula.

VIII. Solve the following problems:

Question 1.
Lemon juice has a pH 2, what is the concentration of H⁺ ions?
Answer:
pH = – log [H⁺]
[H⁺] = antilog of [-pH]
= antilog [-2]
[H⁺] = 10^-2 M
[OR]
PH = – log [H⁺]
[H⁺] = 10^-pH
[H⁺] = 10^-2M

Question 2.
Calculate the pH of 1.0 × 10^-4 molar solution of HNO₃.
Answer:
pH = – log [H⁺]
HNO3 → H⁺ + NO₃^–
pH = -log [1 × 10^-4]
= -(-4)log₁₀ 10 = 4
pH = 4

Question 3.
What is the pH of 1.0 x 10^-5 molar solution of KOH?
Answer:
KOH → K⁺ + OH^–
pOH = -log[OH^–]
= -log [1 × 10^-5]
pOH = 5
pH + pOH = 14
∴ pH of KOH = 14 – 5 = 9
pH = 9

Question 4.
Laundry detergent has a pH 8.5, What is the concentration of H⁺ ions?
Answer:
pH = 8.5
pH = – log [H⁺]
[H⁺] = 10^-pH
[H⁺] = 10^-8.5
[H⁺] = 3.16 × 10^-9 M

Question 5.
The hydroxide ion concentration of a solution is 1 × 10^-11M. What is the pH of the solution?
Answer:
[OH^–] = 1 × 10^-11 M
pOH = – log[OH^–]
= – log[1 × 10^-11]
= -log₁₀1 – log₁₀10^-11
= -(-11) log₁₀10 = 11
pOH = 11
pH + pOH = 14
pH = 14 – 11
pH = 3

Samacheer Kalvi 10th Science Types of Chemical Reactions Additional Important Questions and Answers

I. Choose the correct answer:

Question 1.
The unit of rate of a reaction is:
(a) dm³/mol
(b) dm^-3
(c) mol dm^-3
(d) mol
Answer:
(c) mol dm^-3

Question 2.
As the molecule is dissociated by the absorption of heat it is otherwise called as ______.
(a) Thermolysis
(b) Photolysis
(c) Electrolysis
(d) None of these.
Answer:
(a) Thermolysis

Question 3.
The chemical formula of marble is:
(a) CaCO₃
(b) MgCO₃
(c) Na₂CO₃
(d) PbCO₃
Answer:
(a) CaCO₃

Question 4.
As the decomposition is caused by light, this kind of reaction is called ______.
(a) Thermolysis
(b) Photolysis
(c) Electrolysis
(d) None of these.
Answer:
(b) Photolysis

Question 5.
Fluorine will displace the following halide ion from the solution:
(a) chloride
(b) bromide
(c) iodide
(d) all the above
Answer:
(d) all the above

Question 6.
The decomposition of AgBr into grey coloured silver metal is an example of ……… reaction.
(a) compound to element/element
(b) compound to compound/compound
(c) combination
(d) neutralization
Answer:
(a) compound to element/element

Question 7.
The Metathesis reaction among the following is:
(a) C₃H_8(g) +5O_2(g) → 3CO_2(g) + 4H₂O + heat
(b) Zn_(s) + CuSO_4(aq) → ZnSO_4(aq) + Cu_(s)
(c) HNO_3(aq) + NH₄OH_(aq) → NH₄NO_3(aq) + H₂O_(l)

Answer:
(c) HNO_3(aq) + NH₄OH_(aq) → NH₄NO_3(aq) + H₂O_(l)

Question 8.
KI and Pb(NO₃)₂ solutions are mixed to give a precipitate. What is the colour of the precipitate?
(a) White
(b) Brown
(c) Red
(d) Yellow.
Answer:
(d) Yellow

Question 9.
The pH of rain water is approximately:
(a) 7
(b) 8
(c) 4
(d) 14
Answer:
(a) 7

Question 10.
Most of the reactions go faster at ______.
(a) low temperature
(b) moderate temperature
(c) 0°C
(d) high temperature.
Answer:
(d) high temperature

II. Fill in the blanks.

1. A chemical equation provides information on the ……….. of the substances and the reaction condition.
2. The symbol ‘aq’ in a chemical equation represent the physical state of the substance as ……….
3. 2Na_(s) + Cl_2(g) → 2NaCl_(s) represent the combination reaction between a ……… and ……
4. After white washing with a solution of slaked lime a thin layer of ……….. is formed.
5. Reactions in which heat is absorbed is called ……….. reactions.
6. Electrolytic refining of copper is based on ……….. reaction.
7. When 10^-6 mole of a monobasic strong acid is dissolved in water, the pH of the solution is ………..
8. When pH of a solution is 2, the [H⁺] in mol/L is ……….
9. Combustion of coal is an example of ………. reaction.
10. [ ] represents the concentration of either the reactant or product in ……….
Answer:
1. physical state
2. aqueous solution
3. metal, non-metal
4. CaCO₃
5. endothermic
6. electrolytic decomposition
7. 6
8. 1 × 10^-2
9. irreversible
10. mol/Lit

III. Match the following.

Question 1.
Match the following table:

Answer:
A. (v)
B. (iii)
C. (iv)
D. (ii)
E. (i)

Question 2.
Match the following table:

Answer:
A. (v)
B. (iv)
C. (i)
D. (iii)
E. (ii)

Question 3.
Match the following table:

Answer:
A. (iii)
B. (v)
C. (iv)
D. (ii)
E. (i)

Question 4.
Match the following table:

Answer:
A. (iv)
B. (v)
C. (i)
D. (ii)
E. (iii)

IV. True or False: (if false give the correct statement)

1. Formation of calcium silicate from silica and calcium oxide is a combination reaction.
2. Most of the combination reactions are endothermic in nature.
3. Decomposition of mercuric oxide into mercury and O₂ is an example of . photolysis.
4. Chlorine can displace fluoride ion from its aqueous solution.
5. Magnesium is more reactive than iron.

Answer:

1. True
2. False – Most of the combination reactions are exothermic in nature.
3. False – Decomposition of mercuric oxide into mercury and O₂ is an example of thermolysis.
4. False – Chlorine is less reactive than Fluorine, so it cannot displace fluoride ion from its aqueous solution.
5. True

V. Short answer questions:

Question 1.
Write a note on double displacement reaction with an example.
Answer:
When two compounds react, if their ions are interchanged, then the reaction is called double displacement reaction.
Eg: NaOH_(aq) + HCl_(aq) → NaCl_(aq) + H₂O

Question 2.
Identify the wrong statements and correct them.

1. Sodium benzoate is used in food preservative.
2. Nitric acid is not used as fertilizer in agriculture.
3. Sulphuric acid is called the king of chemicals.
4. The pH of acid is greater than 7.
5. Acetic acid is used in aerated drinks.

Answer:

1. Correct statement.
2. Wrong statement. Nitric acid is used as a fertilizer in agriculture.
3. Correct statement.
4. Wrong statement. The pH of the acid is lesser than 7.
5. Wrong statement. Carbonic acid is used in aerated drinks.

Question 3.
Why a combustion reaction may be called as an exothermic oxidation?
Answer:
In a combustion reaction heat is evolved, it is an exothermic reaction. As oxygen is added, it is also an oxidation. So, combustion may be called as an exothermic oxidation.

Question 4.
Take two conical flasks. Label them as I and II. Take a small amount of copper sulphate solution in the first conical flask. Take a small amount of granulated zinc in the second conical flask. Allow the copper sulphate solution to react with the zinc.

1. Name the type of reaction.
2. Say whether the metal zinc is more reactive or less reactive.
3. Write a complete and balanced reaction.
4. Say whether this change is reversible or irreversible.

Answer:

1. The reaction taken place is displacement reaction.
2. Metal zinc is more reactive.
3. Balanced chemical equation.
   \(\mathrm{Zn}_{(\mathrm{s})}+\mathrm{CuSO}_{4(\mathrm{aq})} \rightarrow \mathrm{ZnSO}_{4(\mathrm{aq})}+\mathrm{Cu}_{(\mathrm{s})} \downarrow\)
4. This change is an irreversible change.

Question 5.
What is an irreversible reaction? Give an example.
Answer:
The reaction that cannot be reversed is called irreversible reaction. The irreversible reactions are unidirectional, i.e., they take place only in the forward direction. Consider the combustion of coal into carbon dioxide and water.

Question 6.
Define the rate of a reaction.
Answer:
“Rate of a reaction is the change in the amount or concentration of any one of the reactants or products per unit time”.
Consider the following reaction,
A → B
The rate of this reaction is given by
Rate = –\(\frac{d[A]}{dt}\) = +\(\frac{d[B]}{dt}\)
Where,
[A] – Concentration of A
[B] – Concentration of B
The negative sign indicates the decrease in the concentration of A with time. The positive sign indicates the increase in the concentration of B with time.

Question 7.
What is meant by combination reaction? Give an example.
Answer:
A reaction in which a single product is formed from two or more reactants is known combination reaction.
2Mg + O₂ → 2MgO.

Question 8.
What is a catalyst?
Answer:
A catalyst is a substance which increases the reaction rate without being consumed in the reaction.

Question 9.
Define Displacement reaction. Give an example.
Answer:
The reaction in which a more reactive element displaces a less reactive element from its compound is called displacement reaction.
\(\mathrm{Pb}+\mathrm{CuCl}_{2} \longrightarrow \mathrm{PbCl}_{2}+\mathrm{Cu} \downarrow\)
Lead displaces copper from copper chloride solution.

Question 10.
When a aerated soft drink bottle is kept open it will go flat. Why?
Answer:
(i) In the sealed aerated soft drink bottle, the dissolved CO₂, in the form of carbonic acid and gaseous CO₂ are in equilibrium.
(ii) When we open the bottle the gaseous CO₂ will escape and the dissolved CO₂ begins to undissolve to the gas phase to maintain the equilibrium. So when we keep the bottle open for a long time it will go flat with all the dissolved CO₂ gone.

Question 11.
Can copper displace zinc or lead from their salt solutions?
Answer:
No, copper cannot displace zinc or lead from their salt solutions. Because copper is less reactive than zinc and lead.

Question 12.
What is called as acid rain?
Answer:
The pH of rain water is approximately ‘7’ but when the air is polluted with oxides of S and N, they get dissolved in the rain water and make its pH less than 7, then it is called acid rain.

Question 13.
Write the differences between combination and decomposition reaction.
Answer:

VI. Answer in detail:

Question 1.
Two acids ‘A’ and ‘B’ were kept in beakers. Acid ‘A’ undergoes partial dissociation in water, whereas acid ‘B’ undergoes complete dissociation in water.

1. Of the two acids ‘A’ and ‘B’ which is weak acid and which is strong acid?
2. What is a weak acid?
3. What is a strong acid?
4. Give one example of each.

Answer:

1. Of the two acids ‘A’ and ‘B’, ‘A’ is a weak acid and ‘B’ is a strong acid.
2. A weak acid is the one which ionises partially when dissolved in water.
3. A strong acid is the one which ionises completely when dissolved in water.
4. Weak acid – Acetic acid(CH₃COOH)
   Strong acid – Sulphuric acid (H₂SO₄).

Question 2.
Sodium hydroxide and HCl acid react as shown in this equation
NaOH_(aq)4 + HCl_(aq) → NaCl_(aq) + H₂O
(i) Which type of chemical reaction is this?
Answer:
Neutralization reaction

(ii) The reaction is exothermic. Explain what that means?
Answer:
When heat is evolved during a chemical reaction it is called exothermic.

(iii) Differentiate exothermic and endothermic reaction.
Answer:
Exothermic :

1. Heat is evolved.
2. Temperature increases.

Endothermic :

1. Heat is absorbed.
2. Temperature decreases.

(iv) What happens to the temperature of the solution as the chemicals react?
Answer:
Temperature of the solution increases.

Question 3.
Take two conical flasks. Label them as I and II. Take a small amount of CuSO₄ in the I conical flask and small amount of granulated Zinc in the II conical flask. Allow the CuSO₄ solution to react with Zinc.
(i) Name the type of reaction.
Answer:
Displacement reaction.

(ii) Say whether the metal Zn is more reactive or less reactive.
Answer:
Zinc is more reactive than Copper.

(iii) Write the complete and balanced reaction.
Answer:
Zn_(s)+ CuSO_4(aq) → ZnSO_4(aq) + Cu_(s)↓

(iv) Say whether this change is reversible or irreversible
Answer:
Irreversible.

Question 4.
Suggest a reason for each observation given below.

1. In fireworks, powdered magnesium is used rather than magnesium ribbon.
2. Zinc and dilute H₂SO₄ react much more quickly when a few drops of copper sulphate solutions are added.
3. The reaction between magnesium carbonate and dilute hydrochloric acid speeds up when some concentrated HCl is added.

Answer:

1. In fireworks, powdered magnesium is used because it has more surface area than magnesium ribbon. Because of more surface area, powdered magnesium reacts faster than magnesium ribbon.
2. Zinc and dilute H2SO4 react much more quickly when a few drops of copper sulphate solution is added. Copper sulphate acts as a catalyst which increases the rate of the reaction.
3. When the concentration of the reactants increases, the rate of the reaction also increases. So the reaction between magnesium carbonate and dilute hydrochloric acid speeds up by the addition of some concentrated HCl.

VII. Hot Questions:

Question 1.

Answer:
According to the rate Law for the reaction.
2N₂O₅ → 4NO₂ + O₂

2K₁ = K₂ = 4K₃ [neglecting negative and positive signs]

Question 2.
When solutions of silver nitrate and potassium bromide are mixed, a pale yellow precipitate is formed.
The ionic equation for the reaction is Ag⁺ + Br^– → AgBr

1. (a) What is the name of the pale yellow precipitate?
   (b) Is it soluble or insoluble?
2. Is the formation of silver bromide precipitate, a result of redox reaction or not? Justify your answer.
3. What is this type of reaction called?

Answer:

1. (a) The pale yellow precipitate is silver bromide.
   (b) Silver bromide is sparingly soluble.
2. Yes, the formation of silver bromide precipitate is due to redox reaction. Ag⁺ gains electron (reduction) and Br^– loses electron (oxidation). So it is a redox reaction.
3. This reaction is a double displacement reaction.

VIII. Numericals:

Question 1.
The hydrogen ion concentration of a fruit juice is 3.3 × 10^-2M. What is the pH of the juice? Is it acidic or basic?
Answer:
[H⁺] = 3.3 × 10^-2 M
Formula:
pH = -log[H⁺]
pH = -log[3.3 × 10^-2]
= -[log 3.3 + log 10^-2]
= -[0.5185 – 2 log₁₀10]
= -0.5185 + 2 log₁₀10 [log₁₀10 = 1]
= -0.5185 + 2
pH = 1.4815
Since pH is less than 7, the solution is acidic.

Question 2.
If a solution has a pH of 7.41, determine its H⁺ concentration.
Answer:
pH = 7.41
Formula:
[H⁺] = antilog[-pH]
= antilog[-7.41] = 10^-7.41
= 3.89 × 10^-8M

Question 3.
The pH of a solution is 5.5 at 25°C. Calculate its [OH^–].
Answer:
pH = 5.5
Since pH + pOH = 14
pOH = 14 – pH
= 14 – 5.5 = 8.5
[OH^–] = 10^-pOH
= 10^-8.5
= 3.16 × 10^-9M
(OR)
[OH^–] = antilog[-8.5]
= 3.16 × 10^-9M
[OH^–] = 3.16 × 10^-9M

Question 4.
Calculate the pH of 0.001 M HCl solution.
Answer:
Since HCl is a strong acid, it dissociates
HCl → H⁺ + Cl^–
[H⁺] = [HCl] = 0.001 M
[H⁺] = 1 × 10^-3M
pH = -log[H⁺]
= -log[1 × 10^-3]
pH = 3

Question 5.
The hydrogen ion concentration of a solution is 1 × 10^-8M.
(i) What is the pH of the solution?
Answer:
pH = -log[1 × 10^-8]
pH = 8

(ii) What is the pOH of the solution?
Answer:
pOH = 14 – 8
= 6

(iii) Is the given solution acidic or basic?
Answer:
Acidic

Question 6.
Calculate the pH of 0.02 M Ba(OH)₂, Ba(OH)₂ solution is a strong electrolyte.
Answer:
[Ba(OH)₂] = 0.02 M
Ba(OH)₂ → Ba²⁺ + 2OH^–
[OH^–] = 2[Ba(OH)₂]
= 2 × 0.02 = 0.04 M
pOH = – log[0.04]
= -log[4 × 10^-2]
= -[log 4 + log 10^-2]
= -[0.6020 – 2 log 10]
pOH = -0.6020 + 2 × 1
= 1.398
pH = 14 – 1.398
= 12.602

Students can download 10th Social Science Geography Chapter 3 Components of Agriculture Questions and Answers, Notes, Samacheer Kalvi 10th Social Science 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 10th Social Science Solutions Geography Chapter 3 Components of Agriculture

Samacheer Kalvi 10th Social Science Components of Agriculture Text Book Back Questions and Answers

I. Choose the correct answer

Question 1.
The soil which is rich in iron oxides is
(a) Alluvial
(b) Black
(c) Red
(d) Alkaline
Answer:
(c) Red

Question 2.
Which of the following organization has divided the Indian soils into 8 major groups?
(a) Indian Council of Agricultural Research
(b) Indian Meteorological Department
(c) Soil Survey of India
(d) Indian Institute of Soil Science
Answer:
(a) Indian Council of Agricultural Research

Question 3.
The soils formed by the rivers are:
(a) Red soils
(b) Black soils
(c) Desert soils
(d) Alluvial soils india.
Answer:
(d) Alluvial soils india.

Question 4.
……….. dam is the highest gravity in India.
(a) Hirakud dam
(b) Bhakra Nangal dam
(c) Mettur dam
(d) Nagaijuna Sagar dam
Answer:
(b) Bhakra Nangal dam

Question 5.
……………… is a cash crop.
(a) Cotton
(b) Wheat
(c) Rice
(d) Maize
Answer:
(a) Cotton

Question 6.
Black soils are also called as ………..
(a) Arid soils
(b) Saline soils
(c) Regur soils
(d) Mountain soils
Answer:
(c) Regur soils

Question 7.
The longest dam in the world is:
(a) Mettur dam
(b) Kosi dam
(c) Hirakud dam
(d) Bhakra Nangal dam
Answer:
(c) Hirakud dam

Question 8.
The leading producer of rice in India is ……….
(a) Punjab
(b) Maharashtra
(c) Uttar Pradesh
(d) West Bengal
Answer:
(c) Uttar Pradesh

Question 9.
Which crop is called as “Golden Fibre” in India?
(a) Cotton
(b) Wheat
(c) Jute
(d) Tobacco
Answer:
(c) Jute

Question 10.
The state which leads in the production of coffee is ……….
(a) West Bengal
(b) Karnataka
(c) Odisha
(d) Punjab
Answer:
(b) Karnataka

II. Consider the given statements and choose the right option given below

Question 1.
Assertion (A): Horticulture involves the cultivation of fruits, vegetables, and flowers.
Reason (R): India ranks first in the world in the production of mango, banana, and citrus fruits.
(a) Both (A) and (R) are true and (R) explains (A)
(b) Both (A) and (R)are true: (R) does not explain (A)
(c) (A) is correct (R) is false
(d) (A) is false (R) is true
Answer:
(c) (A) is correct (R) is false

Question 2.
Assertion(A): Alluvial soil is formed by the deposition of eroded and decayed materials brought by the rivers.
Reason(R): Paddy and wheat are grown well in the soil.
(a) Both (A) and (R) are true and (R) explains (A)
(b) Both (A) and (R)are true and (R) does not explain (A)
(c) (A) is correct (R) is false
(d) (A) is false (R) is true
Answer:
(b) Both (A) and (R)are true and (R) does not explain (A)

III. Pick the odd one out

Question 1.
(a) Wheat
(b) Rice
(c) Millets
(d) Coffee
Answer:
(d) Coffee

Question 2.
(a) Khadar
(b) Bhangar
(c) Alluvial soil
(d) Black soil
Answer:
(d) Black soil

Question 3.
(a) Inundation canals
(b) Perennial canals
(c) Tanks
(d) Canals
Answer:
(c) Tanks

IV. Match the following

Answer:
A. (iv)
B. (iii)
C. (v)
D. (i)
E. (ii)

V. Answer in brief

Question 1.
Define soil.
Answer:
Soil is the uppermost layer of the land surface, usually composed of minerals, organic matter, living organisms, air and water. Its formation is mainly related to the parent rock material, surface relief, climate and natural vegetation.

Question 2.
Name the types of soil found in India.
Answer:
There are 8 major groups of soil found in India classified by the Indian Council of Agricultural Research. They are

1. Alluvial soil
2. Black soil
3. Red soil
4. Forest and Mountain soil
5. Arid and Desert soil
6. Laterite soil
7. Saline and Alkaline soil
8. Peaty and Marshy soil

Question 3.
State any two characteristics of black cotton soil.
Answer:

1. This soil is rich in calcium carbonate, magnesium, potash, lime and iron but deficient in phosphorous. It is clayey and impermeable which has great capacity to retain moisture for a long time.
2. It becomes sticky when wet but develops cracks during dry summer season. The soil is suited for dry farming due to its high moisture retentivity.

Question 4.
What is Multipurpose project?
Answer:

1. Multipurpose projects are the River valley projects.
2. Dams are constructed across rivers aims to serve many purposes such as irrigation, power generation, water supply, controlling floods, navigation, development of fisheries etc.

Question 5.
Define Agriculture.
Answer:
Agriculture is the process of producing food for people, fodder for cattle, fiber and many other desired products by the cultivation of certain plants and the raising of domesticated animals

Question 6.
State the types of agriculture practices in India?
Answer:

1. Owing to physical environment and culture the following cultivation systems prevail in India.
2. Subsistence farming
3. Intensive farming
4. Dry farming
5. Mixed farming agriculture
6. Terrace cultivation

Question 7.
Name the seasons of agriculture in India.
Answer:

1. Kharif Season
2. Rabi Season
3. Zaid Season

Question 8.
Mention the plantation crops of India.
Answer:

1. Plantation crops are mainly cultivated for the purpose of exports.
2. These crops are cultivated in large estates on hilly slopes.
3. Tea, coffee, rubber and spices are the main plantation crops of India.

Question 9.
What do you mean by livestock?
Answer:
Livestocks is defined as farm animals who are raised to generate a profile. It is an integral component of the farming system in India.

Question 10.
Write a brief note on the categories of fisheries in India?
Answer:
In India fisheries are categorised into two.They are marine or sea fisheries and inland or fresh water fisheries.

Marine or Sea fisheries:

1. It includes coastal off-shore and deep sea fishing mainly on continental shelf upto a depth of 200 mts.
2. Kerala leads in Marine fish production.

Inland or Fresh water fisheries:

1. Rivers, lakes, canals, reservoirs, ponds tanks etc are the sources of fresh water fisheries,
2. Andhra Pradesh is leading in the fresh water fisheries.
3. About 50% of the country’s total fish production comes from inland fisheries.

VI. Give reasons

Question 1.
Agriculture is the backbone of India.
Answer:
Agriculture provide food for the entire population. It supplies raw materials to the agro-based industries. It contributes to export trade. So, agriculture is the backbone of India.

Question 2.
Rain water harvesting is necessary.
Answer:
India experiences Tropical monsoon climate. Rainfall in India is seasonal, irregular and uneven and highly eractic. Hence it is necessary’ to save rain water when it is available and use in times of need. In order to prevent surface . run off Rainwater harvesting is needed.

Question 3.
Small farms are predominant in India.
Answer:
The predominant type of Indian agriculture is subsistence farming. In this agriculture land holding is small and half of the production is used for family consumption and the rest is sold in the nearby markets. The farmers concentrate on stage food crops like rice and wheat. As the farmers are poor, they can’t apply the modem inputs which cost more.

VII. Distinguish between the following

Question 1.
Rabi and Kharif crop seasons.
Answer:
Rabi crop season:

1. Rabi crop season is from October – March.
2. Seeds are sown in winter and harvested before summer.
3. Major crops of this season are mainly Wheat, Mustard, Maize etc.

Kharif crop season:

1. Kharif crop season is from June – September.
2. Seeds are sown after the summer monsoon and harvested before winter.
3. Major crops are Rice, Cotton, Groundnut, Turmeric etc.

Question 2.
Inundation canal and perennial canal.
Answer:
Inundation canal:

1. Undependable source of irrigation.
2. Operational only during flood in rivers and not have weir system to regulate water.

Perennial canal:

1. Dependable source of irrigation.
2. Have weir system through barrage to regulate water from perennial rivers or dams.

Question 3.
Marine fishing and Inland fishing.
Answer:
Marine fishing:

1. Marine fishing includes coastal, off¬shore and deep sea fishing mainly on the continental shelf upto a depth of 200m.
2. Kerala is the leading producer in marine fishing.

Inland fishing:

1. Inland fishing is done in rivers, lakes, canals, ponds, tanks, reservoirs etc.
2. Andhra Pradesh, West Bengal, Gujarat, Kerala and TamilNadu are the leading states.

Question 4.
Alluvial soils and Black soils.
Answer:
Alluvial soil:

1. Formed by the sediments deposited by the rivers and streams.
2. Silt clay, sandy and loamy in nature.
3. Found in the river valleys and plains.
4. Rice, wheat, sugarcane grow well in this soil.

Black soil:

1. Formed by the disintegration of basalt rocks.
2. Sticky when wet develops cracks when dry.
3. Found in plateau region especially in Deccan trap.
4. Cotton, sugarcane and tobacco grow well in this soil.

VIII. Answer in a paragraph

Question 1.
State the types of soil in India and explain the characteristics and distribution of soil.
Answer:

Question 2.
Write about any two multipurpose projects of India.
Answer:
A comprehensive river valley project which serves a number of purposes simultaneously is called a “Multi purposes project”.

1. The Bhakra Nangal Project: India’s biggest multipurpose river valley project is ‘Bhakra Nangal Project’. It has been built at a strategic point where two hills on either side of the Sutlej are very close to each other. It is the highest gravity dam in the world. Its length is 226 metres from the river bed. The canals taken out are 1100 kilometres long. The ‘Nangal Power Plant’ on the Sutlej produces electricity, and serves the states of Himachal Pradesh, Punjab, Haryana, Rajasthan and New Delhi. The distributaries are 8400 km in length. It irrigates an area of 1.4 million hectares.

2. Indira Gandhi Project: This project is an ambitious scheme to bring new areas under irrigation so that more areas could be cultivated. The waters of the River Beas and the Ravi are diverted to the River Sutlej. The ‘Pong’ Dam on the River Beas has been constructed to divert the Beas water into the Sutlej in a regulated manner. So that ‘Rajasthan canal’, the longest irrigation canal in the world can irrigate Gandhi Nagar, Bikaner and Jaisalmer districts of North West Rajasthan, (i.e) a part of Thar desert. The main canal now called ‘Indira Gandhi Canal’ is 468 km long runs entirely in Rajasthan, Western of Sutlej, Beas and Ravi are now being fully utilised for irrigating thirsty lands of South Western parts of our country.

Question 3.
Bring out the characteristics of intensive and Plantation farming.
Answer:
Characteristics of Intensive farming:

1. Farming is done with intensification and mechanisation system to maximize yields from available land.
2. In this farming heavy use of pesticides and chemical fertilizers have been applied.
3. It has also been applied to the raising of live stock being held indoor as factory farms.
4. Plantation fanning.
5. Single crop raised on a large area testates).
6. Crops are grown mainly for export purpose,
7. The plantations are mostly owned by companies.

Question 4.
Examine the geographical conditions favourable for the cultivation of rice and wheat.
Answer:
Rice:
Rice is an indigenous crop. India is the second-largest producer of rice in the world. It is a tropical crop which is grown well in alluvial plains and river deltas. It requires a mean monthly temperature of 24°C and an average rainfall of 150 cm and deep fertile alluvial soil for its growth. It also needs an abundant supply of cheap labour. In areas of less rainfall particularly in Punjab and Haryana, it is grown with the help of irrigation.
Rice in India is sown in three ways:

1. Broadcasting,
2. Ploughing or drilling, and
3. Transplanting.

Due to increased use of High Yielding Variety (HYV) seeds (CR Dhan 205, AR Dhan 306, CRR 451 etc.), many of the indigenous varieties were disappeared. In 2016, the first 10 leading rice-producing states are West Bengal (First in India) Uttar Pradesh, Punjab, Tamil Nadu, Andhra Pradesh, Bihar, Chhattisgarh, Odisha, Assam, and Haryana.

Wheat:
Wheat is a temperate crop. Its cultivation is mainly confined to the northwestern part of India. India produces both winter wheat and spring wheat. It is the second most important food crop of the country, after rice.

It requires 10-15°C at the time of sowing and 20-25°C at the time of ripening of grains. Over 85% of India’s wheat production comes from 5 states namely Uttar Pradesh, Punjab, Haryana, Rajasthan and Madhya Pradesh. Apart from these regions, the black soil tract of the Deccan covering parts of Maharashtra and Gujarat also contribute a major wheat production.

IX. HOTS Questions

Question 1.
Can you imagine a world without agriculture?
Answer:
Agriculture is the art and science of cultivating the soil, growing crops and raising livestock. It includes the preparation of plant and animal products for people to use and their distribution to markets.

Agriculture provides most of the world’s food and fabrics. Cotton, wool and leather are all agricultural products. It also provides wood for construction and paper products.

A world without agriculture would be very different compared to the world we live in today. It is easy for us as humans to take for granted things when we don’t really know how they are grown or produced. Without agriculture, we may not get food and clothing. Without timber, we may not be able to build houses and furniture. We may also be deprived of some everyday-products like soap, paper and ethanol, which are made up of some sort of agricultural by-product. Modern medicine also depends on agriculture. Without agriculture, we wouldn’t be here. We must always be thankful for this industry and for those involved in the various activities related to it.

Question 2.
Can you give solutions for the prevailing water disputes in South India (construction of dams / raising of dams / cleaning of tanks}?
Answer:

1. Construction of check dams: In order to prevent surface run off water • during heavy rains. Check dams has to be constructed to regulate the flow of water.
2. Raising of dams: Improves the storage capacity, Strengthening the dams is a must.
3. Cleaning of tanks: Preventing encroachment by strict legal action, desilting the tanks and deepening it in the local areas will provide water supply to the locality, as well as to maintain the areas of ground water level cleaning of tanks is a must

X. Map exercise

Question 1.
Demarcate the major tracts of alluvial soils.
Answer:

Question 2.
Delineate the main regions of black soil.
Answer:

Question 3.
Locate the Hirakud dam, Mettur dam and Damodar dam.
Answer:

Question 4.
Shade the regions of jute cultivation.
Answer:

Question 5.
Mark any three tea and coffee growing areas.
Answer:

Question 6.
Demarcate the regions of desert soil.
Answer:

Question 7.
Locate the fishing hubs: Tuticorin, Chennai,Cochin, Mumbai, Machiiipatnam
Answer:

Question 8.
Demarcate: Cauvery delta, Godavari delta.
Answer:

TB. PNo: 115
Activity 1:

Question 1.
Soil Texture (sand, silt, clay) influence on some properties of soils including water holding capacity. Find out water holding capacity of soils which given above based on following table.
Answer:

TB. PNo: 131
Activity 2:

Question 1.
Complete the following table by your day to day life experience.

Answer:

Samacheer Kalvi 10th Social Science Components of Agriculture Additional Important Questions and Answers

I. Choose the correct answer

Question 1.
……………… soil is formed by the process of leaching.
(a) Alluvial
(b) Black
(c) Laterite
(d) Arid
Answer:
(c) Laterite

Question 2.
Cotton is a ………
(a) food crop
(b) cash crop
(c) dry crop
Answer:
(b) cash crop

Question 3.
……………… is one of the method of soil conservation.
(a) Deforestation
(b) Irrigation
(c) Water logging
(d) Afforestation
Answer:
(d) Afforestation

Question 4.
The “rice bowl of Tamil nadu” is ………..
(a) Madurai
(b) Chennai
(c) Thanjavur
Answer:
(c) Thanjavur

Question 5
……………… are useful for the diversion of flood water from the rivers during rainy season.
(a) Perennial canals
(b) Inundation canals
(c) Open wells
(d) Tube wells
Answer:
(b) Inundation canals

Question 6
The type of fanning which is practised in Punjab and Haryana is ………
(a) subsistence farming
(b) commercial farming
(c) wet farming
Answer:
(b) commercial farming

Question 7.
……………… project is constructed on the river Kaveri in TamilNadu.
(a) Tehri Dam
(b) Kosi Dam
(c) Mettur Dam
(d) Horakud Dam
Answer:
(c) Mettur Dam

Question 8.
In the regions with abundant rainfall ……. is grown.
(a) millet
(b) wheat
(c) rice
Answer:
(c) rice

Question 9.
The traditional farming method that results in low productivity is:
(a) mixed farming
(b) shifting agriculture
(c) intensive farming
(d) subsistence farming
Answer:
(d) subsistence farming

Question 10.
One of the important zaid crops is ………….
(a) rice
(b) wheat
(c) watermelon
Answer:
(c) watermelon

Question 11.
First Live-stock census was conducted in India in the year:
(a) 1819
(b) 1919
(c) 1618
(d) 1981
Answer:
(b) 1919

Question 12.
The National Research Center on Plant Biotechnology was established in ………
(a) 1985
(b) 1980
(c) 1990
Answer:
(a) 1985

II. Consider the given statements and choose the right option given below

Question 1.
Assertion (A): Indian agriculture is largely dominated by food crops. Reason (R): India has a large population.
(a) Both (A) and (R) are true and (R) explains (A)
(b) Both (A) and (R)are true: (R) does not explain (A)
(c) (A) is correct (R) is false
(d) (A) is false (R) is true
Answer:
(c) (A) is correct (R) is false

Question 2.
Assertion (A): Forest and mountain soils differ from region to region. Reason (R): Due to the absence of vegetative cover.
(a) Both (A) and (R) are true and (R) explains (A)
(b) Both (A) and (R)are true: (R) does not explain (A)
(c) (A) is correct (R) is false
(d) (A) is false (R) is true
Answer:
(c) (A) is correct (R) is false
Hint: Reason is due to mechanical weathering caused by snow, rain, temperature variation depending on climate.

Question 3.
Assertion (A): Terrace farming method is practiced on hill and mountain slopes. Reason (R): The availability of land is limited and it checks soil erosion.
(a) Both (A) and (R) are true and (R) explains (A)
(b) Both (A) and (R)are true: (R) does not explain (A)
(c) (A) is correct (R) is false
(d) (A) is false (R) is true
Answer:
(a) Both (A) and (R) are true and (R) explains (A)

Question 4.
Assertion (A): Pulses are usually rotated with other crops.
Reason (R): They are used as human food and feeding cattle.
(a) Both (A) and (R) are true and (R) explains (A)
(b) Both (A) and (R) are true and (R) does not explain (A)
(c) (A) is correct (R) is false
(d) (A) is false (R) is true
Answer:
(c) (A) is correct (R) is false
Hint: They are mostly leguminous in nature and fixes atmospheric nitrogen helps soil to regain its fertility.

III. Pick the odd one out

1. (a) Tea, (b) Sugarcane, (c) Cotton, (d) Ragi
2. (a) Khandsari, (b) Herrings, (c) Mackerels, (d) Eels
3. (a) Damodhar, (b) Mahanadi, (c) Kaveri, (d) Raingun
4. (a) Water wheel, (b) Sprinkler, (c) Open well, (d) poly house
5. (a) Blue Revolution, (b) soil erosion, (c) Green Revolution, (d) Soil erosion
6. (a) Fishing, (b) Kharif, (c) Rabi, (d) Zaid

Answer:

1. (d) Ragi
2. (a) Khandsari
3. (d) Raingun
4. (c) Open well
5. (d) Soil erosion
6. (a) Fishing

IV. Match the following

Question 1.
Match the Column I with Column II.

Answer:
A. (v)
B. (i)
C. (ii)
D. (iii)
E. (iv)

Question 2.
Match the Column I with Column II.

Answer:
A. (ii)
B. (iv)
C. (v)
D. (i)
E. (iii)

Question 3.
Match the Column I with Column II.

Answer:
A. (vi)
B. (iii)
C. (ii)
D. (i)
E. (iv)
F. (v)

V. Answer in brief

Question 1.
Why is tank irrigation more prevalent in South India than North India?
Answer:
The undulated topography of peninsular region forms large depressions to collect water which become tanks. So the tank irrigation is more prevalent in South India than North India.

Question 2.
How laterite soils are formed?
Answer:
Laterite soils are formed in the regions where alternate wet and dry conditions prevail.
It is formed by the process of leaching.

Question 3.
Which is an acute problem in India? How?
Answer:
Soil degradation is an acute problem in India. According to a 2015 report of the Indian institute of remote sensing (IIRS). The estimated the amount of soil .erosion that occurred in India was 147 million hectares.
The main problems of the Indian soils are

1. Soil erosion
2. Degradation of Soil
3. Water-logging
4. Saline and Alkaline and
5. Salt Flats.

Question 4.
Draw a flow chart showing the sources of irrigation and their classification.
Answer:

Question 5.
Write few lines about Rain Gun.
Answer:
It is used to spread water like rain and used to serve for crops which used to grow up to 4 feet or high also but we have to adjust sprinklers height as per crop size, typical usage of Rain guns are in sugarcane, maize crops.

Question 6.
Name the food crops grown in India.
Answer:
Food crops that are grown in India include cereals and pulses amongst which rice, wheat, jowar, bajra, maize, barely, ragi, gram and tur are important.

Question 7.
Give short notes about Terrace cultivation.
Answer:
This is practised especially in hilly areas, where lands are of sloping nature. The hill and mountains slopes are cut to form terraces and the land is used in the same way as in permanent agriculture.

Question 8.
Name the five leading states that contribute 85% of India’s wheat production.
Answer:
Uttar Pradesh, Punjab, Haryana, Rajasthan and Madhya Pradesh are the leading states in wheat production in India.

Question 9.
What are the products of Sugarcane?
Answer:
Sugarcane provides raw material for the sugar industry. Besides providing sugar, gur and Khandsari it supplies molasses for alcohol industry and bagasse for paper industry.

Question 10.
How jute is useful for trade?
Answer:

1. Jute fibre provides raw material for Jute industry.
2. It is used for manufactruing of gunny bags, carpets, hessian, ropes and strings, rugs, clothes, tarpaulins, upholstery etc.

Question 11.
What is the other name of ‘Shifting Agriculture1? Who practice shifting agriculture? and how it is called in different regions?
Answer:
‘Shifting Agriculture’ is also called as ‘Slash and bum’ Agriculture. The tribal people follow this type of agriculture. It is called by different names in different regions in India as follows.

Name	Place
Jhum	Assam
Poonam	Kerala
Podu	Andhra Pradesh, Odisha
Beewar, Mashan, Penda, Beera	Various parts of Madhya Pradesh

Question 12.
What is dry farming?
Answer:
Dry farming is the type of farming practiced in arid areas where there is lack of irrigation facilities. Crops grown in these areas can withstand dry conditions.

Question 13.
What are called cash crops? Give examples.
Answer:
Crops which are cultivated for commercial purpose are called cash crops, eg: Sugarcane, tobacco, fibre crops and oil seeds.

Question 14.
Which is the largest oil seeds producing state? What is the position of India in oil seeds production in the world?
Answer:
Gujarat is India’s largest oil seeds producing state. India is the second largest producer of oil seeds in the world next to China.

Question 15.
Define Green Revolution.
Answer:
The process of improving and increasing the production of food crops using modem techniques is referred as Green Revolution.

Question 16.
Mention the different breeds of cattle population in India.
Answer:
Cattle population in India belongs to different breeds. They are

1. Milch breed
2. Draught breed
3. Mixed or General breed

VI. Give Reasons

Question 1.
Tank irrigation is popular in peninsular India.
Answer:
The undulating relief, absence of perennial rivers, Impermeable rock structure and natural depression are the reasons for having tank irrigation most popular in Peninsular India.

Question 2.
Why tea is grown on the hill slopes?
Answer:
Tea plants require high rainfall but its roots cannot tolerate water logging. Frost condition is a must for tea plants. So it is grown on the hill slopes.

Question 3.
Inundation canals are not dependable source of irrigation.
Answer:
Inundation canals are operational only during rainy season for the diversion of flood water directly from the rivers. Hence these canals are not dependable source of irrigation.

Question 4.
Shifting agriculture is also called as slash and burn agriculture.
Answer:
Once the forest land piece is cleared by tribal people they grow crops for two to three years and bum the stumps after harvest and abandoning the lands to regain its fertility and then move to new areas. Thus, shifting agriculture is also called ‘slash and bum’ agriculture.

Question 5.
Only little surplus is left in subsistence farming.
Answer:
Mainly in subsistence farming crops are grown for family consumption leaving little surplus to sell in the market. Preference will be given to food crops as per their needs.

Question 6.
Indian agriculture is mainly dominated by the food crops.
Answer:
As the population increases the need for food also increase. Due to the need and to supply to the large population Indian agriculture is mainly dominated by the food crops.

VII. Distinguish between the following

Question 1.
Laterite and Red soil.
Solution:
Laterite soil:

1. Femed by the process of leaching under wet and hot dry conditions.
2. Mainly composed of hydrated oxides of iron and aluminium.
3. Found mostly on hilly areas.
4. Suitable for tea, coffee, rubber and cashewnut.

Red soil:

1. Formed by the decomposition of ancient crystalline rocks.
2. Rich in minerals like iron and magnesium.
3. Found in plateau regions.
4. Suitable for pulses and sugarcane.

Question 2.
Arid and desert soil and Peaty and marshy soil.
Answer:
Arid and Desert soil:

1. Formed due to dry climate and high temperature.
2. Poor in organic matter and nitrogen rich in salt content.
3. Found in Rajasthan Northern Gujarat and Southern Punjab.
4. Millets, barley and pulses grow with irrigation.

Peaty and Marshy soil:

1. Formed in humid regions from organic matter.
2. Poor in potash and phosphate rich in vegetable organic matter.
3. Found in coastal areas and Sunderban Deltaic region, Kerala, Odisha, West Bengal.
4. Ideal for paddy and Jute cultivation.

Question 3.
Open well and Tube well irrigation.
Answer:
Open well irrigation:

1. Need sufficient ground water availability.
2. Practiced in areas of Ganga plains and river Deltaic regions.

Tube well irrigation:

1. Can be found in areas of low water table and soft geological subsurface.
2. Need sufficient water supply. Predominant in the states of Gujarat, Maharashtra, Madhya Pradesh and TamilNadu.

Question 4.
Bhakra Nangal and Hirakud project.
Answer:
Bhakra Nangal Project:

1. Constructed on the river Sutlej.
2. Highest gravity dam in the world.
3. Punjab, Haryana and Rajasthan states are benefitted.

Hirakud Project:

1. Constructed on the river Mahanadhi.
2. Longest dam in the world.
3. State of Odhisha is benefitted by this project.

Question 5.
Subsistence and Mixed farming.
Answer:
Subsistence farming:

1. Crops is mainly cultivated for family consumption.
2. Traditional farming methods are used due to small land holdings.
3. Mainly concentrated on food crops.

Mixed farming:

1. Integrated farming to satisfy many needs of the farmers.
2. Modem techniques is used for crop cultivation done in a vast area.
3. System include crop production along with raising live stock, poultry, fisheries, bee keeping etc.

Question 6.
Food and Cash crops.
Answer:
Food crops:

1. Mainly grown for consumption purpose.
2. Food crops include rice, wheat, pulses etc.
3. Apart from consumption used as raw materials for agro based industries.

Cash crops:

1. Crops are cultivated for commercial purpose.
2. Sugarcane, cotton, jute, oil seeds are the main cash crops. .
3. Mainly produced for raw materials for industries and earn valuable foreign exchange.

Question 7.
Rice and Wheat.
Answer:
Rice:

1. Mainly Tropical crop.
2. Need abundant supply of water till harvest.
3. West Bengal, Uttar Pradesh, Punjab, TamilNadu, Andhra Pradesh are some of the leading states in Rice production.

Wheat:

1. Sub tropical or Temperate crop.
2. Need moderate water supply.
3. Uttar Pradesh, Punjab, Haryana, Rajasthan and Madhya Pradesh are the leading states in wheat production.

VIII. Answer in a paragraph

Question 1.
What is a multipurpose project and explain its purpose?
Answer:
A comprehensive river valley project which serves a number of purposes simultaneously is called a “Multipurpose project”. Multipurpose projects serve the following purposes.

1. They help to store water, that can be utilised, when water, is in great demand both for agricultural and domestic purpose.
2. They check floods and famines.
3. Afforestation is undertaken in the catchment areas of river, which helps conservation of water, soil and wildlife. Thus it keeps ecosystem intact.
4. Production of hydro electricity is also another purpose of these projects. It is a pollution free of energy and is renewable energy.
5. They attract tourists and develops tourism industry.
6. Soil conservation and land relamation are other purpose of these projects.

Question 2.
What do you mean by Irrigation? Why it is necessary in India?
Answer:

1. Watering to agricultural lands by artificial means for cultivation is called Irrigation.
2. India is a tropical monsoon country.
3. 75% of rainfall is received within a span of four months.
4. Indian rainfall from monsoons are seasonal, uneven, irregular and erratic in nature.
5. So always there is a need for irrigation to carry out agricultural activities during dry period.
6. Besides erratic rainfall prevalence of high temperature, cultivation of annual crops and hydrophytes.
7. Commercial farming and porous soil make irrigation an essential one for agriculture in India.

Question 3.
What are the different sources of irrigation used in different parts of India?
Answer:
The main sources of irrigations are
1. Canal irrigation
2. Well irrigation
3. Tank irrigation

1. Canal irrigation:
It is the second most important sources of irrigation in India. The Canals are of two types.
i. Inundation canals
ii. Perennial canals

i. Inundation canals:
In this, water is taken directly from the rivers without making any kind of barrage or dam. Such canals are useful for the diversion of flood water from the rivers and remains operational during rainy season.

ii. Perennial canals:
These are developed from perennial work by constructing barrage to regulate the flow of water. These canals are useful for irrigation.

2. Well irrigation:
A Well is a hole or trough usually vertical excavated in the earth for brining groundwater to the surface. It contributes about 62% of net irrigated area in India. Wells are of two types.
i. Open well
ii. Tube well

i. Open well:
This type of irrigation is widely practiced in the areas where groundwater is sufficiently available. The areas are in Ganga plains, the deltaic region of Mahanadi, Godavari, Krishna, Cauvery and parts of Narmada and Tapti valleys.

ii. Tube well:
Tube wells are developed in the areas of low water table, sufficient power supply and soft subsurface geological units. Tube wells are predominant in the states of Gujarat, Maharashtra, Punjab, MP, and Tamil Nadu.

3. Tank irrigation:
A tank is a natural or man-made hollow on the surface developed by constructing a small bund around it across a stream It is used to collect and store water for irrigation and other purpose. It also includes irrigation from taken and ponds.

Question 4.
How is Live-stock census conducted in TamilNadu?
Answer:
State Government is conducting Live stock census with the help of:

1. Department of Animal Husbandary at State level and
2. Regional Joint Director at District level under the guidelines of Government of India ministry of Agriculture and farmers welfare,
3. Department of Animal husbandary, Dairying and Fisheries conducted once in 5 years.

Question 5.
Explain about the major issues faced by the Indian farmers?
Answer:
We can divide the problems faced by the Indian agriculture and by the farmers into two Natural and Man made.
Natural problems:

1. Soil erosion: Large tracts of land suffer from soil erosion by wind and water.
2. Infertile soil: Growing crops for many years without replenishing led to the exhaution of soil and its depletion.
3. Lack of Irrigation: Only some areas of the cropped falls under irrigation.

Man made problems:

1. Small land holdings and fragmented land: Poor status made the farmers to have small land and also some farmers possesses share from their ancestral property cannot afford to apply mechanism.
2. High costs of Inputs: Good quality of seeds are out of reach for many small and marginal farmers due to their high price.
3. Agricultural marketing: Absence of sound marketing, facility, interference of local traders and middlemen for the disposal of their produce, fluctuations in the price.
4. In adequate transport: Lakhs of villages are not w7ell connected with main roads or with market centres. Lack of cheap and efficient means of transportation is not available.
5. Scarcity of capital: Huge capital is needed to purchase advanced farm machineries and equipments which the poor farmers cannot afford to buy.

Question 6.
List out some of the Agricultural Revolutions in India.
Answer:

Question 7.
“Per Drop more Crop”. Explain this statement.
Answer:

1. It is the scheme introduced by the Government of India with the objective to enhance water use efficiency.
2. This micro irrigation scheme comes under “Pradhan Mantri Krishi Sinchayee Yojana (PMKSY) and centrally sponsored scheme on micro irrigation.
3. It promotes appropriate technological interventions like drop and sprinkler irrigation technologies in agriculture and encourage farmers to use water saving and conservation technique.
4. Following five states progressed 78% under micro irrigation scheme
   • Andhra Pradesh
   • Karnataka
   • Gujarat
   • Maharashtra
   • TamilNadu

IX. Map Questions
Mark the following on the outline map of India.

Question 1.
Areas of Red soil and Mountain soil.
Answer:

Question 2.
Demarcate the states producing the highest for the following crops.
Answer:
(i) Paddy

(ii) Sugarcane

(iii) Cotton

(iv) Wheat

Question 3.
Kosi project, Tungabadra, Periyar Dam, Nagarjuna Sagar.
Answer:

Students can download 10th Science Chapter 8 Periodic Classification of Elements Questions and Answers, Notes, Samacheer Kalvi 10th Science 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 10th Science Solutions Chapter 8 Periodic Classification of Elements

Samacheer Kalvi 10th Science Periodic Classification of Elements Text Book Back Questions and Answers

I. Choose the best answer:

Question 1.
The number of periods and groups in the periodic table are:
(a) 6, 16
(b) 7, 17
(c) 8, 18
(d) 7, 18
Answer:
(d) 7, 18

Question 2.
The basis of modem periodic law is ____.
(a) atomic number
(b) atomic mass
(c) isotopic mass
(d) number of neutrons.
Answer:
(a) atomic number

Question 3.
……….. group contains the member of the halogen family.
(a) 17th
(b) 15th
(c) 18th
(d) 16th
Answer:
(a) 17th

Question 4.
_______ is a relative periodic property.
(a) atomic radii
(b) ionic radii
(c) electron affinity
(d) electronegativity.
Answer:
(b) ionic radii

Question 5.
Chemical formula of rust is:
(a) Fe0.xH₂O
(b) Fe04.xH₂O
(c) Fe₂O₃. xH₂O
(d) FeO
Answer:
(c) Fe₂O₃. xH₂O

Question 6.
In the aluminothermic process the role of Al is:
(a) oxidizing agent
(b) reducing agent
(c) hydrogenating agent
(d) sulphurising agent
Answer:
(b) reducing agent

Question 7.
The process of coating the surface of the metal with a thin layer of zinc is called ____.
(a) painting
(b) thinning
(c) galvanization
(d) electroplating.
Answer:
(c) galvanization

Question 8.
Which of the following inert gas has electrons in the outermost shell?
(a) He
(b) Ne
(c) Ar
(d) Kr
Answer:
(a) He

Question 9.
Neon shows zero electron affinity due to ____.
(a) stable arrangement of neutrons
(b) stable configuration of electrons
(c) reduced size
(d) increased density.
Answer:
(b) stable configuration of electrons

Question 10.
……….. is an important metal to form amalgam.
(a) Ag
(b) Hg
(c) Mg
(d) Al
Answer:
(b) Hg

II. Fill in the blanks:

1. If the electronegativity difference between two bonded atoms in a molecule is greater than 1.7, the nature of bonding is ………..
2. …………. is the longest period in the periodical table.
3. ………… forms the basis of modern periodic table.
4. If the distance between two Cl atoms in Cl₂ molecule is 1.98 Å, then the radius of Cl atom is ………..
5. Among the given species A^– A⁺, and A, the smallest one in size is ……….
6. The scientist who propounded the modern periodic law is …………
7. Across the period, ionic radii ………… (increases,decreases).
8. ……….. and ………… are called inner transition elements.
9. The chief ore of Aluminium is ………….
10. The chemical name of rust is ………….
Answer:
1. ionic
2. 6th (sixth) period
3. Atomic number
4. 0.99 Å
5. A⁺
6. Dimitri Mendeleev
7. decreases
8. Lanthanides, Actinides
9. bauxite
10. hydrated ferric oxide

III. Match the following:

Answer:
A. (ii)
B. (v)
C. (iv)
D. (iii)
E. (i)

IV. True or False: (If false give the correct statement)

1. Moseley’s periodic table is based on atomic mass.
2. Ionic radius increases across the period from left to right.
3. All ores are minerals; but all minerals cannot be called as ores.
4. Aluminium wires are used as electric cables due to their silvery white colour.
5. An alloy is a heterogenous mixture of metals.
Answer:
1. False – Moseley’s periodic table is based on atomic number.
2. True
3. True
4. False – Aluminium wires are used as electric cables because it is a good conductor of heat and electricity.
5. False – An alloy is an homogeneous mixture of metals.

V. Assertion and Reason:

Answer the following questions using the data given below:
Question 1.
Assertion: The nature of bond in HF molecule is ionic.
Reason: The electronegativity difference between H and F is 1.9.
(a) Assertion and Reason are correct, Reason explains the Assertion.
(b) Assertion is correct, Reason is wrong.
(c) Assertion is wrong, Reason is correct.
(d) Assertion and Reason are correct, Reason doesn’t explains Assertion.
Answer:
(a) Assertion and Reason are correct, Reason explains the Assertion.

Question 2.
Assertion: Magnesium is used to protect steel from rusting.
Reason: Magnesium is more reactive than iron.
(a) Assertion and Reason are correct, Reason explains the Assertion.
(b) Assertion is correct, Reason is wrong.
(c) Assertion is wrong, Reason is correct.
(d) Assertion and Reason are correct, Reason doesn’t explains Assertion.
Answer:
(a) Assertion and Reason are correct, Reason explains the Assertion.

Question 3.
Assertion: An uncleaned copper vessel is covered with greenish layer. Reason: copper is not attacked by alkali.
(a) Assertion and Reason are correct, Reason explains the Assertion.
(b) Assertion is correct, Reason is wrong.
(c) Assertion is wrong, Reason is correct.
(d) Assertion and Reason are correct, Reason doesn’t explains Assertion.
Answer:
(d) Assertion and Reason are correct, Reason doesn’t explains Assertion.

VI. Short answer questions:

Question 1.
A is a reddish brown metal, which combines with O₂ at < 1370 K gives B, a black coloured compound. At a temperature > 1370 K, A gives C which is red in colour. Find A, B and C with reaction.
Answer:
(A) is a reddish brown metal – Copper

A – Copper; B – Cupric oxide; C – Cuprous oxide.

Question 2.
A is a silvery white metal. A combines with O₂ to form B at 800°C, the alloy of A is used in making the aircraft. Find A and B.
Answer:
A – Silvery white metal – Aluminium

The alloys of aluminium, Duralumin and Magnalium are used in making the aircraft.
A – Aluminium; B – Aluminium oxide.

Question 3.
What is rust? Give the equation for the formation of rust.
Answer:
When iron is exposed to moist air, it forms a layer of brown hydrated ferric oxide on its surface. This compound is known as rust and the phenomenon of formation of rust is known as rusting.
4Fe + 3O₂ + xH₂O → 2Fe₂O₃. xH₂O (Rust).

Question 4.
State two conditions necessary for rusting of iron.
Answer:
(i) The presence of water and oxygen is essential for the rusting of iron.
(ii) Impurities in the iron, the presence of water vapour, acids, salts and CO₂ speeds up rusting.

VII. Long answer questions:

Question 1.
(a) State the reason for addition of caustic alkali to bauxite ore during purification of bauxite.
Answer:
Caustic alkali is added to bauxite, to dissolve bauxite ore and obtain a solution of sodium aluminate.

(b) Along with cryolite and alumina, another substance is added to the electrolyte mixture. Name the substance and give one reason for the addition.
Answer:
CaF₂ (Fluorspar) is added along with cryolite and alumina. It is added to reduce the high melting point of the electrolyte.

Question 2.
The electronic configuration of metal A is 2, 8, 18, 1.
The metal A when exposed to air and moisture forms B a green layered compound. A with con. H₂SO₄ forms C and D along with water. D is a gaseous compound. Find A, B, C and D.
Answer:
Metal (A) with electronic configuration- 2, 8, 18, 1 is copper.
2Cu + O₂ + CO₂ + H₂O → CuCO₃. Cu(OH)₂ (B)
Copper carbonate (Green layer)

(A) – Copper (Cu)
(B) – Copper Carbonate (CuCO₃. Cu(OH)₂)
(C) – Copper Sulphate (CuSO₄)
(D) – Sulphur dioxide (SO₂)

Question 3.
Explain the smelting process.
Answer:
The roasted ore of copper is mixed with powdered coke and sand and is heated in a blast furnace to obtain matte (Cu₂S + FeS) and slag. The slag is removed as waste.
2 FeS + 3O₂ → 2 FeO + 2 SO₂
2 Cu₂S + 3O₂ → 2 Cu₂O + 2SO₂
Cu₂O + FeS → Cu₂S + FeO
FeO + SiO₂ → FeSiO₂ (slag)

VIII. HOT questions:

Question 1.
Metal A belongs to period 3 and group 13. A in red hot condition reacts with steam to form B. A with strong alkali forms C. Find A, B and C with reactions.
Answer:
Metal A belongs to Period 3 and Group 13. So metal ‘A’ is aluminium.
(A) in red hot condition reacts with steam to form ‘B’.

‘A’ with strong alkali forms ‘C’

(A) – Aluminium
(B) – Aluminium oxide
(C) – Sodium meta aluminate

Question 2.
Name the acid that renders aluminium passive. Why?
Answer:
Dilute or concentrated nitric acid (HNO₃) renders aluminium passive. Because nitric acid does not attack aluminium but it renders aluminium passive due to the formation of an oxide film on its surface.

Question 3.
(a) Identify the bond between H and F in HF molecule.
Answer:
Ionic, because the electronegativity difference is more than 1.7.

(b) What property forms the basis of identification?
Answer:
Electronegativity.

(c) How does the property vary in periods and in groups?
Answer:
In a period, from left to right the electronegativity increases because of the increase in the nuclear charge.
In a Group, from top to bottom, the electronegativity decreases because of the increase in size of the elements.

Samacheer Kalvi 10th Science Periodic Classification of Elements Additional Important Questions and Answers

I. Choose the correct answer:

Question 1.
The shortest period in the periodic table contains elements.
(a) 18
(b) 8
(c) 2
(d) 32
Answer:
(c) 2

Question 2.
Group number of carbon family is _____.
(a) 13
(b) 15
(c) 17
(d) 14.
Answer:
(d) 14.

Question 3.
The ore forming elements, chalcogens are present in ……… group of the modern periodic table.
(a) 18th
(b) 1st
(c) 2nd
(d) 16th
Answer:
(d) 16th

Question 4.
Valency of all the alkali metals is _____.
(a) 1
(b) 2
(c) 3
(d) 4.
Answer:
(a) 1

Question 5.
The largest atom in the 2nd period of the periodic table is:
(a) Li
(b) Be
(c) F
(d) Ne
Answer:
(a) Li

Question 6.
The covalent radii of Hydrogen, if the distance between the Hydrogen nuclei of the molecule is 0.74 Å is:
(a) 1.58 Å
(b) \(\frac{0.74}{4}\) Å
(c) 0.37 Å
(d) 0.74 Å
Answer:
(c) 0.37 Å

Question 7.
Pick out the correct ionic radii in increasing order for the following species – Na, Cl, Na⁺, Cl^– _____.
(a) Na > Cl > Na⁺ > Cl^–
(b) Cl > Na > Na⁺ > Cl^–
(c) Cl^– > Na > Na⁺ > Cl
(d) Cl < Na⁺ < Cl^– < Na.
Answer:
(d) Cl < Na⁺ < Cl^– < Na.
Hint:
Na = 186 pm,
Cl = 91 pm,
Na⁺ = 116 pm,
Cl^– = 167 pm.

Question 8.
In the third period, the first ionization potential is of the order:
(a) Na > Al > Mg > Si > P
(b) Mg > Na > Si > P > Al
(c) Na < Al < Mg < Si < P
(d) Na < Al < Mg < Si < P
Answer:
(c) Na < Al < Mg < Si < P

Question 9.
Which one of the following is the least electronegative element?
(a) Bromine
(b) Chlorine
(c) Iodine
(d) Hydrogen
Answer:
(d) Hydrogen

Question 10.
Which is a widely used a scale to determine the electronegativity?
(a) Pauling scale
(b) Moseley scale
(c) Mendeleev scale
(d) none of these.
Answer:
(a) Pauling scale

Question 11.
Which one of the following orders of ionic radii is correct?
(a) H^– > H⁺ > H
(b) Na⁺ > F^– > O^2-
(c) F > O^2- > Na⁺
(d) None of these
Answer:
(d) None of these

Question 12.
The percentage of carbon in Pig iron is:
(a) < 0.25%
(b) 0.25 – 2%
(c) 2 – 4.5%
(d) > 5%
Answer:
(c) 2 – 4.5%

Question 13.
The chemical formula of clay is _____.
(a) Al₂O₃
(b) Al₂O₃.2H₂O
(c) Al₂O₃. 2SiO₂.2H₂O
(d) Al₂O₃. 2SiO₂.H₂O.
Answer:
(c) Al₂O₃. 2SiO₂.2H₂O

Question 14.
The temperature in the combustion zone is maintained at:
(a) 1500°C
(b) 400°C
(c) 1000°C
(d) 1380°C
Answer:
(a) 1500°C

Question 15.
Oil used in Froth floatation method is _____.
(a) pine oil
(b) natural oil
(c) crude oil
(d) Synthetic oil.
Answer:
(a) pine oil

Question 16.
The first most abundant metal present in the Earth crust is:
(a) Iron
(b) Aluminium
(c) Zinc
(d) Copper
Answer:
(b) Aluminium

Question 17.
……….. metal is used for making calorimeters.
(a) Copper
(b) Tin
(c) Mercury
(d) Iron
Answer:
(a) Copper

Question 18.
More reactive metal is _____.
(a) Zn
(b) Fe
(c) Ag
(d) Na.
Answer:
(d) Na.

Question 19.
The chief ore of Iron is:
(a) Magnesite
(b) Galena
(c) Cinnabar
(d) Haematite
Answer:
(d) Haematite

Question 20.
The metal which melts at room temperature is:
(a) Zinc
(b) Lead
(c) Gallium
(d) Tin
Answer:
(c) Gallium

Question 21.
Conversion of bauxite into alumina is _____.
(a) Hall’s process
(b) Alumino thermic process
(c) Baeyer’s process
(d) Bessemerisation process.
Answer:
(c) Baeyer’s process

Question 22.
………. metal can be cut with knife.
(a) Potassium
(b) Gallium
(c) Mercury
(d) Gold
Answer:
(a) Potassium

Question 23.
………. is not a good conductor of heat and electricity.
(a) Silver
(b) Tungsten
(c) Copper
(d) Aluminium
Answer:
(b) Tungsten

Question 24.
Electrolyte used in Hall’s process ______.
(a) Pure alumina + molten cryolite + fluorspar
(b) Pure alumina + molten bauxite + fluorspar
(c) Pure bauxite + molten cryolite + fluorspar
(d) Pure bauxite + molten Haematite + fluorspar.
Answer:
(a) Pure alumina + molten cryolite + fluorspar

Question 25.
The foaming agent used for froth floatation process is:
(a) Coconut oil
(b) Pine oil
(c) Sodium chloride
(d) Groundnut oil
Answer:
(b) Pine oil

Question 26.
Three elements A, B and C are having the electronic configuration Is² 2s¹, Is² 2s² and Is² 2s² 2p¹ respectively. Which element will have the lowest ionization energy?
(a) A
(b) B
(c) C
(d) B and C
Answer:
(a) A

Question 27.
Metal used in household utensils is ______.
(a) Al
(b) Co
(c) Fe
(d) Na.
Answer:
(a) Al

Question 28.
Which one of the following pair is a metalloid?
(a) Na and K
(b) F and Cl
(c) Cu and Hg
(d) Si and Ge
Answer:
(d) Si and Ge

Question 29.
The highly metallic element will have the configuration of:
(a) 2, 8, 7
(b) 2, 8, 8, 5
(c) 2, 8, 8, 1
(d) 2, 8, 2
Answer:
(c) 2, 8, 8, 1

Question 30.
The metal used in electroplating is ______.
(a) Cu
(b) Al
(c) Fe
(d) Co.
Answer:
(a) Cu

Question 31.
The flux which is used when the gangue present in the ore is acidic:
(a) Silica
(b) Calcium oxide
(c) Calcium silicate
(d) Cuprous sulphide
Answer:
(b) Calcium oxide

Question 32.
Matte is a mixture of:
(a) Cu₂O + Cu₂S
(b) Cu₂O + FeS
(c) Cu₂S + FeS
(d) Cu₂O + PbS
Answer:
(c) Cu₂S + FeS

Question 33.
Fe reacts with dilute nitric acid in cold condition to give ______.
(a) Ferrous nitride
(b) Ferrous nitrate
(c) Ferric nitride
(d) Ferric nitrate.
Answer:
(b) Ferrous nitrate

Question 34.
In the brass alloy, which is solvent?
(a) Zn
(b) Co
(c) Ag
(d) Cu.
Answer:
(d) Cu.

II. Fill in the blanks:

1. The major component of the matte is ………….
2. The modern periodic table is based on ………..
3. The valency of alkali metals is …………
4. The unreactive elements are present in group ………..
5. In the 2nd period, the smallest atom is ……….
6. The size of a cation is ………… than the neutral atom.
7. ……….. is the unit of ionization energy.
8. The ionization energy ……… down the group in the periodic table.
9. The electron affinities of noble gases are …………
10. ………. is the process of extracting the ore from the Earth’s crust.
11. Galena is the ore of …………..
12. The silvery white metal which is a good conductor of heat and electricity is …………
13. The slag formed during Bessemerisation process is ………….
14. Blister copper contains ………. percentage of copper.
15. Haematite ore is concentrated by ……….. washing.
Answer:
1. Cu₂S
2. atomic number
3. one
4. 18
5. Neon
6. smaller
7. KJ/mol
8. decreases
9. zero
10. Mining
11. lead
12. aluminium
13. Iron silicate or FeSiO₃
14. 98%
15. hydraulic

III. Match the following:

Question 1.
Match the column I with column II.

Answer:
A. (iv)
B. (v)
C. (i)
D. (ii)
E. (iii)

Question 2.
Match the column I with column II.

Answer:
A. (ii)
B. (iv)
C. (v)
D. (iii)
E. (i)

Question 3.
Match the column I with column II.

Answer:
A. (iii)
B. (iv)
C. (v)
D. (i)
E. (ii)

Question 4.
Match the column I with column II.

Answer:
A. (v)
B. (iv)
C. (ii)
D. (iii)
E. (i)

IV. True or false. (If false give the correct statement)

1. Alkali metals are generally extracted by the electrolysis of their ores in fused state.
2. Every mineral is an ore but every ore is not a mineral.
3. Slag is a product formed during smelting by combination of flux and impurities.
4. Reactive metals occur in native state.
5. Malachite is a sulphide ore of copper.
6. Lanthanides are present in the 6th group of the periodic table.
7. Atomic radius increases as we go across the period due to increase in size.
8. As the positive charge increases, the size of the cation decreases.
9. If the difference in electronegativity is greater than 1.7, the bond is considered to be covalent.
10. Siderite is the carbonate ore of calcium.
Answer:
1.True
2. True
3. True
4. False – Reactive metals always occur in the combined state.
5. False – Malachite is the carbonate ore of copper.
6. False – Lanthanides are present in the 6th period of the periodic table.
7. False – Atomic radius increases as we go across the period due to decrease in size.
8. True
9. False – If the difference in electronegativity is greater than 1.7, the bond is considered to be ionic.
10. False – Siderite is the carbonate ore of Iron.

V. Assertion and Reason:

Answer the following questions using the data given below:
Question 1.
Assertion: Zinc blende is concentrated by Froth floatation process.
Reason: Zinc blende is a sulphide ore.
(a) Assertion and Reason are correct, Reason explains the Assertion.
(b) Assertion is correct, Reason is wrong.
(c) Assertion is wrong, Reason is correct.
(d) Assertion and Reason are correct, Reason doesn’t explains Assertion.
Answer:
(a) Assertion and Reason are correct, Reason explains the Assertion.

Question 2.
Assertion: In thermite welding, aluminium powder and Fe₂O₃ are used.
Reason: Aluminium powder is a strong reducing agent.
(a) Assertion and Reason are correct, Reason explains the Assertion.
(b) Assertion is correct, Reason is wrong.
(c) Assertion is wrong, Reason is correct.
(d) Assertion and Reason are correct, Reason doesn’t explains Assertion.
Answer:
(a) Assertion and Reason are correct, Reason explains the Assertion.

Question 3.
Assertion: To design the body of an aircraft, aluminium alloys are used.
Reason: Aluminium becomes passive when it is treated with dil or con.HNO₃
(a) Assertion and Reason are correct, Reason explains the Assertion.
(b) Assertion is correct, Reason is wrong.
(c) Assertion is wrong, Reason is correct.
(d) Assertion and Reason are correct, Reason doesn’t explains Assertion.
Answer:
(d) Assertion and Reason are correct, Reason doesn’t explains Assertion.

Question 4.
Assertion: Tinstone and the impurity wolframite are seperated by magnetic separation.
Reason: Tinstone is magnetic and wolframite is non-magnetic in nature.
(a) Assertion and Reason are correct, Reason explains the Assertion.
(b) Assertion is correct, Reason is wrong.
(c) Assertion is wrong, Reason is correct.
(d) Assertion and Reason are correct, Reason doesn’t explains Assertion.
Answer:
(a) Assertion and Reason are correct, Reason explains the Assertion.

Question 5.
Assertion: Bauxite is purified by leaching.
Reason: Bauxite undergoes thermal decomposition.
(a) Assertion and Reason are correct, Reason explains the Assertion.
(b) Assertion is correct, Reason is wrong.
(c) Assertion is wrong, Reason is correct.
(d) Assertion and Reason are correct, Reason doesn’t explains Assertion.
Answer:
(b) Assertion is correct, Reason is wrong.

VI. Short answer questions:

Question 1.
State the modern periodic law.
Answer:
The physical and chemical properties of the elements are the periodic function of their atomic number.

Question 2.
‘X’ is a silvery white metal. X reacts with O₂ to form Y. The same compound is obtained from the metal on reaction with steam with the liberation of hydrogen gas. Identify X and Y.
Answer:
(i) Silvery white metal ‘X’ is Aluminium.
(ii) It reacts with O₂ to form ‘Y’

(iii) Y can also be obtained on reaction with steam with the liberation of H₂.

Question 3.
Write any four characteristics of periods.
Answer:

• In a period, the electrons are filled in the same valence shell of all elements.
• As the electronic configuration changes along the period, the chemical properties of the elements also change.
• The atomic size of the elements in a period decreases from left to right
• In a period, die metallic character of the element decreases, while their non-metallic character increases.

Question 4.
Write the Principle of Hydraulic washing.
Answer:
The difference in the densities or specific gravities of the ore and the gangue is the main principle behind this method.

Question 5.
What are coinage metals?
Answer:
Copper, silver and gold are called coinage metals, as they are used in making coins and jewellery.

Question 6.
How will you separate tinstone from wolframite?
Answer:
Magnetic separation method. Tinstone is magnetic in nature.
Method: The crushed ore is placed over a conveyer belt which rotates around two metal wheels, one of which is magnetic. The magnetic particles are attracted to the magnetic wheel and fall separately apart from the non¬magnetic particles.

Question 7.
What are ores?
Answer:
The mineral from which a metal can be readily and economically extracted on a large scale is said to be ore.
eg. Bauxite Al₂O₃.2H₂O is the ore of Aluminium

Question 8.
Define electronegativity.
Answer:
It is the tendency of an element in a covalent bond to attract the shared pair of electrons towards itself. It is a relative property.

Question 9.
In what period and group will an element with z = 118 will be present?
Answer:
Elements with z = 118 will be present in Period number ‘7’ and Group number 18.

Question 10.
Why flux is added during metallurgy?
Answer:
Flux is the substance added to the ore to reduce the fusion temperature and to remove impurities.
e.g. CaO, SiO₂

Question 11.
State the trends in the electronegativity in a Group and period.
Answer:
In a Group: Electronegativity decreases in a group because of the increased number of energy levels.
In a Period: The electronegativity increases because the increase in the nuclear charge.

Question 12.
Write a note about smelting.
Answer:
Smelting is a process of reducing the roasted metallic oxide to metal in a molten condition. In this process, impurities are removed by the addition of flux as slag.

Question 13.
Write the formula of the ores of Aluminium.
Answer:

Question 14.
Explain the action of Aluminium with air.
Answer:
On heating at 800°C, aluminium bums in the air very brightly forming its oxide and nitride.
4Al + 3O₂ → 2Al₂O₃ (Aluminium oxide)
2Al + N₂ → 2AlN (Aluminium nitride).

Question 15.
What happen when Aluminium reacts with steam?
Answer:
When steam is passed over red hot aluminium, H₂ gas is evolved.

Question 16.
Write the reaction of Aluminium with Sodium hydroxide?
Answer:

Question 17.
Explain the electrolytic refining of copper.
Answer:
Cathode: A thin plate of pure copper metal.
Anode: A block of impure copper metal.
Electrolyte: Copper sulphate solution + dilute H₂SO₄
When an electric current is passed through the electrolytic solution, pure copper gets deposited at the cathode and the impurities are settled at the bottom of the anode as anode mud.

Question 18.
Mention the uses of Aluminium.
Answer:
Aluminium is used in

1. household utensils
2. electrical cable industry
3. making aeroplanes and other industrial machine parts.

Question 19.
What are the methods employed to make an alloy?
Answer:

1. By fusing the metals together. Eg: Brass is made by melting zinc and copper.
2. By compressing finely divided metals. Eg: wood mexai.

Question 20.
Write the components of wood metal.
Answer:
Wood metal is an alloy of Lead, Tin, Bismuth and Cadmium.

Question 21.
What are the uses of copper?
Answer:

• Copper is used in manufacturing electric cables and other electric appliances.
• Copper is used for making utensils, containers, calorimeters and coins.
• Copper is used in electroplating.
• Copper is alloyed with gold and silver for making coins and jewels.

Question 22.
Give example for non-ferrous copper and aluminium alloys. Non-ferrous copper alloys: Brass (Cu, Zn), Bronze (Cu, Sn)
Answer:
Non-ferrous aluminium alloys: Duralumin (Al, Mg, Cu, Mn), Magnalium (Al, Mg)

Question 23.
How is rust formed?
Answer:
When iron is exposed to moist air, it forms a layer of brown hydrated Ferric oxide on its surface. This compound is known as rust.
4Fe + 3O₂ + xH₂O → 2Fe₂O₃. xH₂O (Rust).

Question 24.
Why are the alloys prepared?
Answer:

1. To modify appearance and colour.
2. To modify chemical activity.
3. To lower the melting point.
4. To increase hardness and tensile strength.
5. To increase resistance to electricity.

Question 25.
Define corrosion.
Answer:
Corrosion is the gradual destruction of metals by chemical or electrochemical reaction with the environment.

Question 26.
What are alloys? How are they prepared?
Answer:

• An alloy is a homogeneous mixture of a metal with other metals or with non-metals that are fused together. e.g. Brass is an alloy of zinc (solute) in copper (solvent)
• Alloys are prepared by fusing the metals together.
• Alloys are prepared by compressing finely divided metals one over the other.

Question 27.
Which is known as Wet corrosion or Electrochemical corrosion?
Answer:
The corrosive action in the presence of moisture is called wet corrosion. It occurs as a result of electrochemical reaction of metal with water or aqueous solution of salt or acids or bases.

Question 28.
Write a note on Cathodic protection.
Answer:
It is the method of controlling corrosion of a metal surface protected is coated with the metal which is easily corrodible. The easily corrodible metal is called Sacrificial metal to act as anode ensuring cathodic protection.

Question 29.
What are the methods used to prevent corrosion?
Answer:
Corrosion of metals is prevented

• by coating with paints
• by coating with oil and grease
• by alloying with other metals
• by the process of galvanization
• by electroplating
• by sacrificial protection

Question 30.
A reddish brown metal ‘A’ reacts with dil.HCl in the presence of O₂ and forms the compound ‘B’. ‘B’ can also be prepared by heating the metal A with Cl₂. Identify A and B.
Answer:
Reddish brown metal ‘A’ is copper.
(A) reacts with dil.HCl in the presence of O₂ and forms CuCl₂ which is ‘B’.

(B) can also prepared by the action of Cl₂.

Question 31.
Write the uses of copper.
Answer:

1. It is extensively used in manufacturing electric cables and other electric appliances.
2. It is used for making utensils, containers, calorimeters and coins.
3. It is used in electroplating.
4. It is alloyed with gold and silver for making coins and jewels.

Question 32.
Write the name and formula of the ores of iron.
Answer:

Question 33.
Define periodicity.
Answer:
The electronic configurations of elements help us to explain the periodic recurrence of physical and chemical properties. Anything which repeats itself after a regular interval is called periodic and this behaviour is called periodicity.

Question 34.
What happens in the combustion zone during the extraction of iron.
Answer:
The temperature in the combustion zone is 150°C. In this region coke bums 02 to form CO₂, when the charge comes in contact with a hot blast of air.

Question 35.
Explain the reactions taking place in the reduction zone.
Answer:
In the upper region of reduction zone, the temperature is at 400°C. In this region CO reduces ferric oxide to form spongy iron.

Question 36.
Define Metallic radius.
Answer:
It is defined as half the distance between the nuclei of adjacent metal atoms.

Question 37.
Complete the following reactions.

1. 4Fe + 10HNO₃ → 4Fe(NO₃)₂ + ………. + 3H₂O
2. 2Fe + 6H₂SO₄ → Fe₂(SO₄)₃ + ………. + 6H₂O

Answer:

1. NH₄NO₃
2. 3SO₂

Question 38.
What happens when steam is passed over red hot iron?
Answer:
When steam is passed over red hot iron magnetic oxide is formed.
3Fe + 4H₂O (steam) → Fe₃O₄ + 4H₂↑

Question 39.
Define Electron affinity.
Answer:
Electron affinity is the amount of energy released when a gaseous atom gains an electron to form its anion. It is also measured in kJ / mol.

Question 40.
Complete the table.
Answer:

Question 41.
Define Metallurgy.
Answer:
Metallurgy is a science of extracting metals from their ores and modifying the metals into alloys for various uses, based on their physical and chemical properties and their structural arrangement of atoms.

Question 42.
Write a short note on leaching or chemical process.
Answer:
This method is employed when the ore is in a very pure form. The ore is treated with a suitable reagent such that the ore is soluble in it but the impurities are not. The impurities are removed by filtration. The solution of the ore, ie., the filtrate is treated with a suitable reagent which precipitates the ore.
E.g. Bauxite Al₂O₃.2H₂O, the ore of aluminium.

Question 43.
Relate all the four columns of the table with their unique properties.
Answer:

Question 44.
Guess Who I am?
(i) I am preserved in Kerosene.
Answer:
Sodium

(ii) My ore is leached with NaOH.
Answer:
Aluminium

(iii) I sacrifice myself to protect my friend Iron.
Answer:
Magnesium

(iv) I am being used in propellers
Answer:
Nickel steel

Question 45.
Explain the method of making alloys.
Answer:

• By fusing the metals together. E.g. Brass is made by melting zinc and copper.
• By compressing finely divided metals. E.g. Wood metal: an alloy of lead, tin, bismuth and cadmium powder is a fusible alloy.

Question 46.
Write the differences between a mineral and a ore.
Answer:

VII. Long answer questions:

Question 1.
Write the reactions taking place during Bessemerisation of copper.
Answer:
2 FeS + 3O₂ → 2FeO + 2SO₂↑

2Cu₂S + 3O₂ → 2 Cu₂O + 2 SO₂↑
2Cu₂O + Cu₂S → 6 Cu + SO₂↑

Question 2.
How do electronegativity values help to find out the nature of bonding between atoms?
Answer:

• If the difference in electronegativity between two elements is 1.7, the bond has 50% ionic character and 50 % covalent character.
• If the difference is less than 1.7, the bond is considered to be covalent.
• If the difference is greater than 1.7, the bond is considered to be ionic.

Question 3.
Explain Froth floatation with diagram.
Answer:
Principle: This process depends on the preferential wettability of the ore with oil (pine oil) and the gangue particles by water. Lighter ores, such as sulphide ores, are concentrated by this method. Eg: Zinc blende (ZnS).

Question 4.
Explain the Baeyer’s process of conversion of Bauxite into alumina.
Answer:
(i) Bauxite ore is finely ground and heated under pressure with a solution of concentrated caustic soda solution at 150°C to obtain sodium meta aluminate.
(ii) On diluting sodium meta aluminate with water, a precipitate of aluminium hydroxide is formed.
(iii) The precipitate is filtered, washed, dried and ignited at 1000°C to get alumina.

Question 5.
Explain the Hall’s Process of electrolytic reduction of alumina with diagram.
Answer:
Hall’s Process:
Aluminium is produced by the electrolytic reduction of fused alumina (Al₂O₃) in the electrolytic cell.
Cathode : Iron tank linked with graphite
Anode : A bunch of graphite rods suspended in molten electrolyte.
Electrolyte : Pure alumina + molten cryolite + fluorspar (fluorspar lowers the fusion temperature of electrolyte)

Temperature: 900 – 950 °C
Voltage used: 5 – 6 V
Overall reaction: 2 Al₂O₃ → 4 Al + 3O₂↑

Question 6.
Write the reaction involved in the middle region of blast furnace during the extraction of iron.
Answer:
The Middle Region (Fusion Zone): The temperature prevails at 1000°C. In this region, CO₂ is reduced to CO.

Limestone decomposes to calcium oxide and CO₂.

These two reactions are endothermic due to absorption of heat. Calcium oxide combines with silica to form calcium silicate slag.
CaO + SiO₂ → CaSiO₃

Question 7.
What are the three different types of iron? Write their uses.
Answer:
(i) Pig iron (Iron with 2-4.5% of carbon): It is used in making pipes, stoves, radiators, railings, manhole covers and drain pipes.
(ii) Steel (Iron with < 0.25% of carbon): It is used in the construction of buildings, machinery, transmission cables and T. V towers and in making alloys.
(iii) Wrought iron (Iron with 0.25-2% of wraught carbon): It is used in making springs, anchors and electromagnets.

Question 8.
What is corrosion? Write the chemistry behind the formation of rust.
Answer:
(i) The slow and steady destruction of a metal by chemical or electro chemical reaction with the environment.
(ii) When the surface of iron is exposed to moisture and other gases present in the atmosphere, the following chemical reaction takes place.
Fe → Fe²⁺ + 2e^–
O₂ + 2H₂O + 4e^– → 4OH^–
O₂ + 4H⁺ + 4e^– → 2H₂O
The Fe²⁺ ions are oxidised to Fe³⁺ ions.
The Fe³⁺ ions combine OH^– ions to form Fe(OH)₃. This becomes rust which is hydrated ferric oxide with the formula Fe₂O₃.xH₂O. It is a reddish brown substance.

Question 9.
Explain the methods of preventing corrosion.
Answer:
(i) Alloying : The metals can be alloyed to prevent the process of corrosion. Eg: Stainless Steel

(ii) Surface Coating : It involves application of a protective coating over the metal. It is of the following types:
(a) Galvanization: It is the process of coating zinc on iron sheets by using electric current.
(b) Electroplating: It is a method of coating one metal over another metal by passing electric current.
(c) Anodizing: It is an electrochemical process that converts the metal surface into a decorative, durable and corrosion resistant. Aluminium is widely used for anodizing process.
(d) Cathodic Protection: It is the method of controlling corrosion of a metal surface protected is coated with the metal which is easily corrodible. The easily corrodible metal is called sacrificial metal to act as anode ensuring cathodic protection.

Question 10.
Discuss the main featured of Periods in the modern periodic table (or) long form of periodic table.
Answer:
The horizontal rows are called periods.There are seven periods in the periodic table.

1. First period (Atomic number 1 and 2): This is the shortest period. It contains only two elements (Hydrogen and Helium).
2. Second period (Atomic number 3 to 10): This is a short period. It contains eight elements (Lithium to Neon).
3. Third period (Atomic number 11 to 18): This is also a short period. It contains eight elements (Sodium to Argon).
4. Fourth period (Atomic number 19 to 36): This is a long period. It contains eighteen elements (Potassium to Krypton). This includes 8 normal elements and 10 transition elements.
5. Fifth period (Atomic number 37 to 54): This is also a long period. It contains 18 elements (Rubidium to Xenon). This includes 8 normal elements and 10 transition elements.
6. Sixth period (Atomic number 55 to 86): This is the longest period. It contains 32 elements (Caesium to Radon). This includes 8 normal elements, 10 transition elements and 14 inner transition elements (Lanthanides).
7. Seventh period (Atomic number 87 to 118): Like the sixth period, this period also accommodates 32 elements. Recently 4 elements have been included by IUPAC.

Question 11.
Discuss the main feature of Groups in the long form of periodic table.
Answer:
(i) The vertical columns in the periodic table starting from top to bottom are called groups. There are 18 groups in the periodic table.

(ii) Based on the common characteristics of elements in each group, they can be grouped as various families.

(iii) The Lanthanides and Actinides, which form part of Group 3 are called inner transition elements.

(iv) Except ‘group O’, all the elements present in each group have the same number of electrons in their valence shell and thus have the same valency. Eg: all the elements of group 1 have one electron in their valence shells (Is¹). So, the valency of all the alkali metals is ‘ 1’.

(v) As the elements present in a group have identical valence shell electronic configurations, they possess similar chemical properties.

(vi) The physical properties of the elements in a group such as melting point, boiling point and density vary gradually.

(vii) The atoms of the ‘group 0’ elements have stable electronic configuration in their valence shells and hence they are unreactive.

VIII. Hot Questions:

Question 1.
Why noble gases have zero electron affinity value?
Answer:
Noble gases show no tendency to accept electrons because the outers and p orbitals of noble gases are completely filled. No more electrons can be added to them and hence their electron affinities are zero.

Question 2.
Arrange the following ions in order of their increasing ionic radii.
Answer:
Li⁺, Mg²⁺, K⁺ Al³⁺
Al³⁺ < Li⁺ < Mg²⁺ < K⁺

Question 3.
Cationic radius is smaller than its corresponding neutral atom. Why?
Answer:
When a neutral atom lose one or more electrons it forms a cation.
Na → Na⁺ + e^–
The radius of this cation (r_Na+)is decreased than its parent atom (r_Na).
When an atom is charged to cation, the number of nuclear charges becomes greater than the number of orbital electrons. Florence the remaining electrons are more strongly attracted by the nucleus. Hence the cationic radius is smaller than its corresponding neutral atom.

Students can Download Samacheer Kalvi 10th Maths Model Question Paper 5 English Medium Pdf, Samacheer Kalvi 10th Maths Model Question Papers helps you to revise the complete Tamilnadu State Board New Syllabus, helps students complete homework assignments and to score high marks in board exams.

Tamil Nadu Samacheer Kalvi 10th Maths Model Question Paper 5 English Medium

Instructions

• The question paper comprises of four parts.
• You are to attempt all the parts. An internal choice of questions is provided wherever applicable.
• All questions of Part I, II, III and IV are to be attempted separately.
• Question numbers 1 to 14 in Part I are Multiple Choice Quèstions of one-mark each. These are to be answered by choosing the most suitable answer from the given four alternatives and.writing the option code and the corresponding answer.
• Question numbers 15 to 28 in Part II àre two-marks questions. These are to be answered in about one or two sentences.
• Question numbers 29 to 42 in Part III are five-marks questions. These are to be answered in about three to five short sentences.
• Question numbers 43 to 44 in Part IV are eight-marks questions. These are to be answered in detail. Draw diagrams wherever necessary.

Time: 3 Hours
Maximum Marks: 100

PART – I

I. Choose the correct answer. Answer all the questions. [14 × 1 =14]

Question 1.
The range of the relation R = {(x, x²) x is a prime number less than 13} is ………… .
(1) {2, 3, 5, 7}
(2) (2, 3, 5, 7, 11}
(3) {4,9,25,49, 121}
(4) {1, 4, 9, 25, 49, 121}
Answer:
(3) {4,9,25,49, 121}

Question 2.
If g = {(1,1),(2, 3),(3,5),(4,7)} is a function given by g(x) = αx + β then the values of α and β are ……….. .
(1) (-1,2)
(2) (2,-1)
(3) (-1,-2)
(4) (1,2)
Answer:
(2) (2,-1)

Question 3.
The sum of the exponents of the prime factors in the prime factorization of 1729 is ……….. .
(1) 1
(2) 2
(3) 3
(4) 4
Answer:
(3) 3

Question 4.
The next term of the sequence \(\frac{3}{16}, \frac{1}{8}, \frac{1}{12}, \frac{1}{18}\) is ……….. .
(1) \(\frac{1}{24}\)
(2) \(\frac{1}{27}\)
(3) \(\frac{2}{3}\)
(4) \(\frac{1}{81}\)
Answer:
(2) \(\frac{1}{27}\)

Question 5.
If (x – 6) is the HCF of x² – 2x – 24 and x² – kx – 6 then the value of k is ……….. .
(1) 3
(2) 5
(3) 6
(4) 8
Answer:
(2) 5

Question 6.
The solution of (2x – 1)² = 9 is equal to ……….. .
(1) -1
(2) 2
(3) -1,2
(4) None of these
Answer:
(3) -1,2

Question 7.
In a given figure ST || QR, PS = 2 cm and SQ = 3 cm. Then the ratio of the area of ∆PQR to the area of ∆PST is ……….. .

(1) 25 : 4
(2) 25 : 7
(3) 25 :11
(4) 25 : 13
Answer:
(1) 25 : 4

Question 8.
The slope of the line joining (12, 3), (4, a) is \(\frac { 1 }{ 8 }\). The value of ‘a’ is ……….. .
(1) 1
(2) 4
(3) -5
(4) 2
Answer:
(4) 2

Question 9.
If sin θ + cos θ = a and sec θ + cosec θ = b, then the value of b (a² – 1) is equal to ……….. .
(1) 2 a
(2) 3 a
(3) 0
(4) 2 ab
Answer:
(1) 2 a

Question 10.
The curved surface area of a right circular cone of height 15 cm and base diameter 16 cm is ……….. .
(1) 60π cm²
(2) 68π cm²
(3) 120π cm²
(4) 136π cm²
Answer:
(4) 136π cm²

Question 11.
The sum of all deviations of the data from its mean is ……….. .
(1) always positive
(2) always negative
(3) zero
(4) non-zero integer
Answer:
(3) zero

Question 12.
If \(\left( \begin{matrix} x+y & x-y \\ 7 & 6 \end{matrix} \right) =\left( \begin{matrix} 10 & 2 \\ 7 & z \end{matrix} \right) \) then x, y, z are ……….. .
(1) 4, 6, 6
(2) 6, 6, 4
(3) 6, 4, 6
(4) 4, 4, 6
Answer:
(3) 6, 4, 6

Question 13.
If the n^th term of a sequence is 100n + 10 then the sequence is ……….. .
(1) an A.P.
(2) a G.P.
(3) a constant sequence
(4) neither A.P. nor G.P.
Answer:
(1) an A.P.

Question 14.
Probability of getting 3 heads or 3 tails in tossing a coin 3 times is ……….. .
(1) \(\frac { 1 }{ 8 }\)
(2) \(\frac { 1 }{ 4 }\)
(3) \(\frac { 3 }{ 8 }\)
(4) \(\frac { 1 }{ 2 }\)
Answer:
(2) \(\frac { 1 }{ 4 }\)

PART – II

II. Answer any ten questions. Question No. 28 is compulsory. [10 × 2 = 20]

Question 15.
Let A = {x ∈ W / x < 2}, B = {x ∈ N / 1 < x ≤ 4} and C = {3, 5} find the value of (A × C) ∪ (B × C)
Answer:
A × C = {0,1} × {3,5}
= {(0,3 (0,5) (1,3) (1,5)}
B × C= (2,3,4) × (3,5)
= {(2,3) (2,5) (3,3) (3,5) (4,3) (4,5)}
(A × C) ∪ (B × C) = {(0,3) (0,5) (1,3) (1,5) (2,3) (2,5) (3,3) (3,5) (4,3) (4,5)}

Question 16.
Find k if fof(k) = 5 where f(k) = 2k – 1.
Answer:
fof(k) = f(f(k)) = 2(2k – 1)-1 = 4k – 3.
Thus, fof(k) = 4k – 3
But, it is given that fof(k) = 5
∴ 4k – 3 = 5 ⇒ k = 2.

Question 17.
Find the sum of the following 6 + 13 + 20 +…. + 97
Answer:
Here a = 6, d = 13 – 6 = 7, l = 97
n = \(\frac{l-a}{d}+1\)
= \(\frac{97-6}{7}+1\) = \(\frac{91}{7}+1\) = 13 + 1 = 14
S_n = \(\frac{n}{2}\)(a + l)
S_n = \(\frac{14}{2}\)(6 + 97) = 7 × 103 = 721

Question 18.
Rekha has 15 square colour papers of sizes 10 cm, 11 cm, 12 cm, …,.24 cm. How much area can be decorated with these colour papers?
Answer:
Area of 15 square colour papers
= 10² + 11² + 12² + …. + 24²
= (1² + 2² + 3² + …. + 24²) – (1² + 2² + 9²)
= \(\frac{24 \times 25 \times 49}{6}-\frac{9 \times 10 \times 19}{6}\)
=4 × 25 × 49 – 3 × 5 × 19
= 4900 – 285
= 4615
Area can be decorated is 4615 cm²

Question 19.
Simplify \(\frac{x+2}{4 y} \div \frac{x^{2}-x-6}{12 y^{2}}\)
Answer:

x² – x – 6 = (x – 3) (x + 2)
= \(\frac{x+2}{4 y} \div \frac{x^{2}-x-6}{12 y^{2}}=\frac{x+2}{4 y}+\frac{(x-3)(x+2)}{12 y^{2}}\)
= \(\frac{(x+2)}{4 y} \times \frac{12 y^{2}}{(x-3)(x+2)}\)
= \(\frac{3 y}{x-3}\)

Question 20.
Solve \(\frac{x}{x-1}+\frac{x-1}{x}=2 \frac{1}{2}\)
Answer:
Let y = \(\frac{x}{x-1}\) then \(\frac{1}{y}=\frac{x-1}{x}\)
Therefore, \(\frac{x}{x-1}+\frac{x-1}{x}=2 \frac{1}{2}\) becomes \(y+\frac{1}{y}=\frac{5}{2}\)
2y² – 5y + 2 = 0 then, y = \(\frac{1}{2}, 2\)
\(\frac{x}{x-1}=\frac{1}{2}\) we get, 2x = x – 1 implies x = – 1
\(\frac{x}{x-1}=2\) we get, x = 2x – 2 implies x = 2
∴ The roots are x = -1, 2

Question 21.
Construct a 3 × 3 matrix whose elements are given by a_ij = |i – 2j|
Answer:
a_ij = |i – 2j|
The general 3 × 3 matrices is
A = \(\left( \begin{matrix} { a }_{ 11 } & { a }_{ 12 } & { a }_{ 13 } \\ { a }_{ 21 } & { a }_{ 22 } & { a }_{ 23 } \\ { a }_{ 31 } & { a }_{ 32 } & { a }_{ 33 } \end{matrix} \right)\)
a₁₁ = |1 – 2(1)| = |1 – 2| = |-1| = 1
a₁₂ = |1 – 2(2)| = |1 – 4| = |-3| = 3
a₁₃ = |1 – 2(3)| = |1 – 6| = |-5| = 5
a₂₁ = |2 – 2(1)| = |2 – 2| = 0
a₂₂ = |2 – 2(2)| = |2 – 4| = |-2| = 2
a₂₃ = |2 – 2(3)| = |2 – 6| = |-4| = 4
a₃₁ = |3 – 2(1)| = |3 – 2| = |1| = 1
a₃₂ = |3 – 2(2)| = |3 – 4| = |-1| = 1
a₃₃ = |3 – 2(3)| = |3 – 6| = |-3| = 3
The required matrix A = \(\left[ \begin{matrix} 1 & 3 & 5 \\ 0 & 2 & 4 \\ 1 & 1 & 3 \end{matrix} \right] \)

Question 22.
The length of the tangent to a circle from a point P, which is 25 cm away from the centre is 24 cm. What is the radius of the circle?
Answer:

Let the radius AB be r. In the right ∆ ABO,
OB² = OA² + AB²
25² = 24² + r²
25² – 24² = r²
(25 + 4) (25 – 24) = r²
r = √49 = 7
Radius of the circle = 7 cm

Question 23.
If the straight lines 12y = – (p + 3)x + 12, 12x – 7y = 16 are perpendicular then find ‘p’.
Answer:
Slope of the first line 12y = -(p + 3)x + 12
y = \(-\frac{(p+3) x}{12}+1\) (comparing with y = mx + c)
Slope of the second line (m₁) = \(\frac{-(p+3)}{12}\)
Slope of the second line 12x – 7y = 16
(m₂) = \(\frac{-a}{b}=\frac{-12}{-7}=\frac{12}{7}\)
Since the two lines are perpemdicular.
m₁ × m₂ = -1
\(\frac{-(p+3)}{12} \times \frac{12}{7}=-1 \Rightarrow \frac{-(p+3)}{7}=-1\)
-(p + 3) = -7
– p – 3 = – 7 ⇒ -p = -7 + 3
– p = -4 ⇒ p = 4
The value of p = 4

Question 24.
Prove that 1 + \(\frac{\cot ^{2} \theta}{1+\csc \theta}\) = cosec θ
Answer:

Question 25.
Find the standard deviation of first 21 natural numbers.
Answer:
Here n = 21
Standard deviation of the first ‘n’ natural numbers,
= \(\sqrt{\frac{n^{2}-1}{12}}\)
1,2,3,4, ……. , 21 = \(\sqrt{\frac{21^{2}-1}{12}}=\sqrt{\frac{441-1}{12}}=\sqrt{\frac{440}{12}}\)
= \(\sqrt{36.666}\) = \(\sqrt{36.67}\)
= 6.055 = 6.06
Standard deviation of first 21 natural numbers = 6.06

Question 26.
How many litres of water will a hemispherical tank hold whose diameter is 4.2m?
Answer:
Radius of the tank = \(\frac{4.2}{2}\) = 2.1 m
Volume of the hemisphere = \(\frac{2}{3}\) πr³ cu. unit
= \(\frac{2}{3} \times \frac{22}{7}\) × 2.1 × 2.1 × 2.1 m³
= 19.404 m³
= 19.4o4 × 1000 litre
= 19,4o4 litres

Question 27.
A two digit number is formed with the digits 2, 5, 9 (repetition is allowed). Find the probability that the number is divisible by 2.
Answer:
Sample space (S) = {22, 25, 29, 55, 59, 52, 99, 92, 95}
n(S) = 9
Let A be the event of getting number divisible by 2
A = {22,52,92}
n(A) = 3
P(A) = \(\frac{n(\mathrm{A})}{n(\mathrm{S})}=\frac{3}{9}=\frac{1}{3}\)

Question 28.
Solve √x + 5 = 2x + 3 using formula method.
Answer:
\(\sqrt{x+5}\) = 2x + 3
\((\sqrt{x+5})^{2}\) = (2x + 3)²
x + 5 = 4x² + 9 + 12x
4x² + 11x + 4 = 0
Here a = 4, b = 11, c = 5
x = \(\frac{-b \pm \sqrt{b^{2}-4 a c}}{2 a}\)
= \(\frac{-11 \pm \sqrt{121-64}}{8}\)
= \(\frac{-11 \pm \sqrt{57}}{8}\)
∴ x = \(\frac{-11+\sqrt{57}}{8}\) ; x = \(\frac{-11-\sqrt{57}}{8}\)

PART – III

III. Answer any ten questions. Question No. 42 is compulsory. [10 × 5 = 50]

Question 29.
An open box is to be made from a square piece of material, 24 cm on a side, by cutting equal squares from the comers and turning up the sides as shown. Express the volume V of the box as a function of x.

Question 30.
Find the greatest number consisting of 6 digits which is exactly divisible by 24,15,36?

Question 31.
The present value of a machine is ₹40,000 and its value depreciates each year by 10%. Find the estimated value of the machine in the 6th year.

Question 32.
The sum of the digits of a three-digit number is 11. If the digits are reversed, the new number is 46 more than five times the old number. If the hundreds digit plus twice the tens digit is equal to the units digit, then find the original three digit number?

Question 33.
Find the square root of the expression \(\frac{4 x^{2}}{y^{2}}+\frac{20 x}{y}+13-\frac{30 y}{x}+\frac{9 y^{2}}{x^{2}}\)

Question 34.
If α, β are the roots of 7x² + ax + 2 = 0 and if β – α = \(\frac { -13 }{ 7 }\) . Find the values of a.

Question 35.
State and prove Angle Bisector Theorem.

Question 36.
A quadrilateral has vertices at A(-4, -2) , B(5, -1) , C(6, 5) and D(-7, 6). Show that the mid-points of its sides form a parallelogram.

Question 37.
Two ships are sailing in the sea on either side of the lighthouse. The angles of depression of two ships as observed from the top of the lighthouse are 60° and 45° respectively.
If the distance between the ships is 200 \(\left(\frac{\sqrt{3}+1}{\sqrt{3}}\right)\) meters, find the height of the light house.

Question 38.
A shuttle cock used for playing badminton has the shape of a frustum of a cone is mounted on a hemisphere. The diameters of the frustum are 5 cm and 2 cm. The height of the entire shuttle cock is 7 cm. Find its external surface area.

Question 39.
Two dice are rolled together. Find the probability of getting a doublet or sum of faces as 4.

Question 40.
Given f(x) = x – 2 ; g(x) = 3x + 5; h(x) = 2x – 3 verify that (goh) of = go (hof)

Question 41.
A 20 m deep well with inner diameter 7 m is dug and the earth from digging is evenly spread out to form a platform 22m by 14m. Find the height of the platform.

Question 42.
The mean and standard deviation of 20 items are found to be 10 and 2 respectively. At the time of checking it was found that an item 12 was wrongly entered as 8. Calculate the correct mean and standard deviation.

PART – IV

IV. Answer all the questions. [2 × 8 = 16]

Question 43.
(a) Construct a triangle similar to a given triangle PQR with its sides equal to \(\frac { 7 }{ 3 }\) of the corresponding sides of the triangle PQR (scale factor \(\frac { 7 }{ 3 }\)).

[OR]

(b) Draw a circle of diameter 6 cm from a point P, which is 8 cm away from its centre. Draw the two tangents PA and PB to the circle and measure their lengths.

Question 44.
(a) Draw the graph of y = x² – 5x – 6 and hence solve x² – 5x – 14 = 0.

[OR]

(b) Solve graphically 2x² + x – 6 = 0.

Students can download 10th Science Chapter 20 Breeding and Biotechnology Questions and Answers, Notes, Samacheer Kalvi 10th Science 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 10th Science Solutions Chapter 20 Breeding and Biotechnology

Samacheer Kalvi 10th Science Breeding and Biotechnology Text Book Back Questions and Answers

I. Choose the correct answer:

Question 1.
Which method of crop improvement can be practised by a farmer if he is inexperienced?
(a) clonal selection
(b) mass selection
(c) pureline selection
(d) hybridisation
Answer:
(b) mass selection

Question 2.
Pusa Komal is a disease resistant variety of ______.
(a) sugarcane
(b) rice
(c) cow pea
(d) maize.
Answer:
(c) cow pea

Question 3.
Himgiri developed by hybridisation and selection for disease resistance against rust pathogens is a variety of:
(a) chilli
(b) maize
(c) sugarcane
(d) wheat
Answer:
(d) wheat

Question 4.
The miracle rice which saved millions of lives and celebrated its 50th birthday is ______.
(a) IR – 8
(b) IR – 24
(c) Atomita – 2
(d) Ponni.
Answer:
(a) IR – 8

Question 5.
Which of the following is used to produce products useful to humans by biotechnology techniques?
(a) enzyme from organism
(b) live organism
(c) vitamins
(d) both (a) and (b)
Answer:
(a) enzyme from organism

Question 6.
We can cut the DNA with the help of ______.
(a) scissors
(b) restriction endonucleases
(c) knife
(d) RNAase.
Answer:
(b) restriction endonucleases

Question 7.
rDNA is a:
(a) vector DNA
(b) circular DNA
(c) recombinant of vector DNA and desired DNA:
(d) satellite DNA
Answer:
(c) recombinant of vector DNA and desired DNA:

Question 8.
DNA fingerprinting is based on the principle of identifying ______ sequences of DNA.
(a) single-stranded
(b) mutated
(c) polymorphic
(d) repetitive.
Answer:
(d) repetitive

Question 9.
Organisms with modified endogenous gene or a foreign gene are also known as:
(a) transgenic organsims
(b) genetically modified
(c) mutated
(d) both (a) and (b)
Answer:
(a) transgenic organsims

Question 10.
In a hexaploid wheat (2n = 6x = 42) the haploid (n) and the basic (x) number of chromosomes respectively are ______.
(a) n = 7 and x = 21
(b) n = 21 and x = 21
(c) n = 7 and x = 7
(d) n = 21 and x = 7.
Answer:
(d) n = 21 and x = 7.

II. Fill in the blanks:

1. Economically important crop plants with superior quality are raised by ………..
2. A protein rich wheat variety is ………
3. ………. is the chemical used for doubling the chromosomes.
4. The scientific process which produces crop plants enriched with desirable nutrients are called ………
5. Rice normally grows well in alluvial soil, but ………… is a rice variety produced by mutation breeding that grows well in saline soil.
6. ……….. technique made it possible to genetically engineer living organism.
7. Restriction endonucleases cut the DNA molecule at specific positions known as …………
8. Similar DNA fingerprinting is obtained for ………..
9. ………… cells are undifferentiated mass of cells.
10. In gene cloning the DNA of interest is integrated in a …………
Answer:
1. Hybridization
2. Altas 66
3. Colchicine
4. Bio fortification
5. Atomita 2 rice
6. Recombinant
7. Phosphodiester
8. Identical twins
9. stem cells
10. bacterial cell

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

1. Raphanobrassica is a tetraploid man-made genus produced by colchicine treatment.
2. The process of producing an organism with more than two sets of chromosome is called mutation.
3. A group of plants produced from a single plant through vegetative or asexual reproduction are called a pureline.
4. Iron fortified rice variety determines the protein quality of the cultivated plant.
5. Golden rice is a hybrid.
6. Bt gene from bacteria can kill insects. ,
7. In vitro fertilisation means the fertilisation done inside the body.
8. DNA fingerprinting technique was developed by Alec Jeffrey.
9. Molecular scissors refers to DNA ligases.
Answer:
1. False – Raphanobrassica is a allotetra ploid man-made genus produced by colchicine treatment.
2. False – The process of producing an organism with more than two sets of chromosome is called polyploidy.
3. True
4. False – Iron rich rice variety determines the protein quality of the cultivated plant.
5. False – Golden rice is a genetically modified plant
6. True
7. False – In vitro fertilisation means the fertilisation done outside the body.
8. True
9. False – Molecular scissors refers to Restriction enzymes

IV. Match the following:

Answer:
A. (iii)
B. (v)
C. (ii)
D. (i)
E. (iv)
F. (viii)
G. (vi)
H. (vii)

V. Understand the assertion statement, justify the reason given and choose the correct choice:

(a) Assertion is correct and reason is wrong.
(b) Reason is correct and the assertion is wrong.
(c) Both assertion and reason is correct.
(d) Both assertion and reason is wrong.
1. Assertion : Hybrid is superior than either of its parents.
Reason: Hybrid vigour is lost upon inbreeding.
Answer:
(c) Both assertion and reason is correct.

2. Assertion: Colchicine reduces the chromosome number.
Reason: It promotes the movement of sister chromatids to the opposite poles.
Answer:
(d) Both assertion and reason is wrong.

3. Assertion: rDNA is superior over hybridisation techniques.
Reason: Desired genes are inserted without introducing the undesirable genes in target organisms.
Answer:
(a) Assertion is correct and reason is wrong.

VI. Answer in a sentence:

Question 1.
Give the name of the wheat variety having higher dietary fibre and protein.
Answer:
Triticale a hybrid of wheat having dietary fibre and protein.

Question 2.
Semi-dwarf varieties were introduced in rice. This was made possible by the presence of the dwarfing gene in rice. Name this dwarfing gene.
Answer:
The dwarfing gene is Sd.I.

Question 3.
Define genetic engineering.
Answer:
Genetic engineering is the manipulation and transfer of genes from one, organism to another organism to create a new DNA called as recombinant DNA(rDNA).

Question 4.
Name the types of stem cells?
Answer:
Embryonic stem cell and Adult stem cell or somatic stem cell, are the two types of stem cells.

Question 5.
What are transgenic organisms?
Answer:
Plants or animals expressing a modified endogenous gene or a foreign gene is known as transgenic organism.

Question 6.
State the importance of bio-fertiliser.
Answer:
Increasing the harvest yields, improving soil structure, better water relation, economical, eco – friendly and more efficient farms are due importance of biofertilizer.

VII. Short Answers Questions:

Question 1.
Discuss the method of breeding for disease resistance.
Answer:

Question 2.
Name three improved characteristics of wheat that helped India to achieve high productivity.
Answer:

1. High yielding
2. Semi – dwarf
3. Fertilizer responsive.

These are the three improved characteristics of wheat that helped India to achieve high productivity. Sonalika and Kalyan Sona are the high yielding varieties of wheat.

Question 3.
Name two maize hybrids rich in amino acid lysine.
Answer:
Protina, shakthi are the maize hybrids rich in amino acid lysin.

Question 4.
Distinguish between
(a) somatic gene therapy and germ line gene therapy.
Answer:
Somatic gene therapy :
It is the replacement of defective gene in somatic cells.

Germ line gene therapy :
It is replacement of defective gene in germ cell (egg and sperm).

(b) undifferentiated cells and differentiated cells.
Answer:
Undifferentiated cells :
The cells which have not become specialized are called undifferentiated cells.
Eg: Cells in early embryos

Differentiated cells :
The cells which have become specialized for doing certain job.
Eg: Muscle cell, nerve cell.

Question 5.
State the applications of DNA fingerprinting technique.
Answer:
DNA fingerprinting technique is widely used in forensic applications such as identifying the – culprit. It is also used for paternity testing in case of disputes. It also helps in the study of genetic diversity of population, evolution and speciation.

Question 6.
How are stem cells useful in regenerative process?
Answer:
If cells, tissues and organs in the body get permanently damaged or lost due to genetic condition or disease or injury, it can be cured by regeneration process of stem cell. In stem cell therapy, stem cells are used to replace the damage of lost cells.

Question 7.
Differentiate between outbreeding and inbreeding.
Answer:
Outbreeding Inbreeding

VIII. Long Answers Questions:

Question 1.
What are the effects of hybrid vigour in animals?
Answer:
The superiority of the hybrid, obtained by cross-breeding is called heterosis or hybrid vigour.
Effects of hybrid vigour in animal breeding:

• Increased production of milk by cattle.
• Increased production of an egg by poultry.
• High quality of meat is produced.
• The increased growth rate in domesticated animals.

Question 2.
Describe mutation breeding with an example.
Answer:
Mutation is defined as the sudden heritable change in the nucleotide sequence of DNA in an organism. It is a process by which genetic variations are created which in turn brings about changes in the organism. The organism which undergoes mutation is called a mutant.

The factors which induce mutations are known as mutagens or mutagenic agents. Mutagens are of two types namely physical mutagens and chemical mutagens.
(i) Physical mutagens : Radiations like X-rays, a, (3 and y-rays, UV rays, temperature etc. which induce mutations are called physical mutagens
(ii) Chemical mutagens : Chemical substances that induce mutations are called chemical mutagens. Eg: Mustard gas and nitrous acid. The utilisation of induced mutation in crop improvement is called mutation breeding.

Achievements of mutation breeding: Some achievements of mutation breeding are-
(a) Sharbati Sonora wheat produced from Sonora-64 by using gamma rays.
(b) Atomita 2 rice with saline tolerance and pest resistance
(c) Groundnuts with thick shells

Question 3.
Biofortification may help in removing hidden hunger. How?
Answer:
Biofortification is the scientific process of helping crop plants, enriched with high levels of desirable nutrients like vitamins, proteins and minerals. Micronutrient malnutrition is called hidden hunger, the lack of micronutrients such as vitamin A, zinc and iron in the diet.

Biofortification is effective in removing hidden hunger and improving the nutritional value of food. Scientists breed crops whose edible parts (seed, tuber and roots) have improved nutritional value. Biofortified foods can contribute to body stores of micronutrients throughout the life cycle.
Some example of crop varieties developed as a result of biofortification are:

• Protina, Shakti and Rathna are lysine-rich maize hybrids.
• Atlas 66, a protein-rich wheat variety.
• Iron-rich fortified rice variety.
• Vitamin A enriched carrots, pumpkin and spinach.

Question 4.
With a neat labelled diagram explain the techniques involved in gene cloning.
Answer:

In gene cloning, a gene or a piece of DNA fragment is inserted into a bacterial cell where DNA will be multiplied (copied) as the cell divides. A brief outline of the basic steps involved in gene cloning are:

1. Isolation of desired DNA fragment by using restriction enzymes.
2. Insertion of the DNA fragment into a suitable vector (Plasmid) to make rDNA.
3. Transfer of rDNA into bacterial host cell (Transformation)
4. Selection and multiplication of recombinant host cell to get a clone.
5. Expression of cloned gene in host cell.
   Using this strategy several enzymes, hormones and vaccines can be produced.

Question 5.
Discuss the importance of biotechnology in the field of medicine.
Answer:
Using genetic engineering techniques, medicinally important valuable proteins or polypeptides, which form the potential pharmaceutical products for the treatment of various diseases have been developed on a commercial scale.
Pharmaceutical products developed by rDNA technique:

• Insulin used in the treatment of diabetes.
• Human growth hormone used for treating children with growth deficiencies.
• Blood clotting factors are developed to treat haemophilia.
• Tissue plasminogen activator is used to dissolve blood clots and to prevent heart attack.
• Development of vaccines against various diseases like hepatitis B and rabies.

IX. Higher Order Thinking Skills: (HOTS)

Question 1.
A breeder wishes to incorporate desirable characters into the crop plants. Prepare a list of characters he will incorporate.
Answer:
Tallness and profuse branching are desirable characters for fodder crop.

Question 2.
Organic farming is better than Green Revolution. Give reasons.
Answer:
Green revolution is the process of increasing food production through high yielding crop varieties and modem agricultural techniques. Organic farming is a method of crop production in an ecofriendly and pollution free environment to release nutrients to crop. As organic farming is an ecofriendly and pollution free, it is better than green revolution.

Question 3.
Polyploids are characterised by gigantism. Justify your answer.
Answer:
An organism having more than 2 sets of chromosomes is called polyploid. It can be induced by physical events such as heat or cold treatment, X – rays and chemical agents like colchicine. Polyploid cell or organism has three or more times the haploid chromosomal number.

Polyploid has a major role in the evolution of both wild and cultivated plants. Polyploid has a key role in plant breeding. There are increase and increased woodiness which has been observed in some insular plants. So polyploids are characterized by gigantism.

Question 4.
‘P’ is a gene required for the synthesis of vitamin A. It is integrated with genome of ‘Q’ to produce genetically modified plant ‘R’
(i) What is P, Q and R?
(ii) State the importance of ‘R’ in India.
Answer:
(i) P is Beta carotene gene
Q Bio fortification
R Golden rice

(ii) Golden rice is genetically modified rice can produce beta carotene,that prevent vitamin A deficiency.

Samacheer Kalvi 10th Science Breeding and Biotechnology Additional Important Questions and Answers

I. Choose the correct answer:

Question 1.
Modem biotechnology consist:
(a) Genetic engineering
(b) Tissue culture
(c) Gene cloning
(d) All of the above
Answer:
(d) All of the above

Question 2.
The disease-resistant cauliflower variety is ______.
(a) Himgiri
(b) Pusa Shubhra
(c) Pusa Komal
(d) IR – 8.
Answer:
(b) Pusa Shubhra

Question 3.
Transgenic animals has:
(a) Foreign DNA in all its cell
(b) Foreign RNA in all its cells
(c) Foreign DNA in some of the cells
(d) Both (b) and (c)
Answer:
(a) Foreign DNA in all its cell

Question 4.
The gamete cells, which have only one set of chromosomes is called ______.
(a) diploid
(b) polyploid
(c) triploid
(d) haploid.
Answer:
(d) haploid.

Question 5.
A kind of Biotechnology involving manipulation of DNA is:
(a) DNA replication
(b) Denaturation
(c) Genetic Engineering
(d) Renaturation
Answer:
(c) Genetic Engineering

Question 6.
A foreign DNA and plasmid cut by the same restriction endonuclease can be joined to form a recombinant plasmid using:
(a) ECORI
(b) Taq polymerase
(c) Polymerase III
(d) Ligase
Answer:
(d) Ligase

Question 7.
Consumption of which one of the following foods can prevent the kind of blindness associated with Vitamin ‘A’ deficiency?
(a) Golden Rice
(b) Bt-Brinjal
(c) Flaver savr tomato
(d) Canolla
Answer:
(a) Golden Rice

Question 8.
Restriction endonucleses are enzymes which:
(a) Remove nucleotides from the ends of the DNA molecule.
(b) Make cuts at specific positions within the DNA molecule.
(c) Recognise a specific nucleotide sequence for binding of DNA ligase.
(d) Restrict the action of the enzyme DNA polymerase.
Answer:
(b) Make cuts at specific positions within the DNA molecule.

Question 9.
……….. is the Father of Indian Green Revolution.
(a) Nammalvar
(b) Dr Borloug
(c) Dr M.S.Swaminathan
(d) Dr Sultan Ismail
Answer:
(c) Dr M.S.Swaminathan

Question 10.
New lined of sheep developed in Punjab is:
(a) Sahiwal
(b) Hisardale
(c) Triticale
(d) Sharbati sonara
Answer:
(b) Hisardale

II. Fill in the blanks:

1. ………. is a cross between Male Donkey and Female Horse.
2. ……….. is a DNA molecule found in the cytoplasm of bacterial cell.
3. ………. was the first cloned female sheep.
4. Human insulin can be synthesized by using ……….
5. In genetic engineering, a DNA segment is transfered to the host cell through ………..
6. Genetically identical individuals are ………..
7. Ligase is used for joining two ………..
8. Enzyme that cleaves nucleic acids within the polynucleotide chain is known as …………
9. The bacterium used as biopesticide is …………
10. A strain of golden rice contains high content of …………..
Answer:
1. Mule
2. Plasmid
3. Dolly
4. rDNA technology
5. Vector
6. Clones
7. DNA fragments
8. Endonuclease
9. Bacillus thuringiensis.
10. Vitamin A

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

1. The structure used to transfer the piece of DNA attached to it into a host ceil is vector.
2. Restriction endonucleases are used to join the DNA fragments having sticky ends.
3. The progeny of a single individual obtained by self breeding is clonal selection.
4. The aim of crop improvement is to develop improved crop varieties.
5. International Rice Research institute (IRRI) is in Indonesia.

Answer:

1. True
2. False – Restriction endonucleases are used to join the DNA fragments having ligase ends.
3. False – The progeny of a single individual obtained by self breeding is pureline selection.
4. True
5. False – International Rice Research institute (IRRI) is in Philippines.

IV. M.atch the following:

Answer:
A. (v)
B. (i)
C. (ii)
D. (iii)
E. (iv)

V. Understand the assertion statement, justify the reason given and choose the correct choice:

(a) Assertion is correct and reason is wrong
(b) Reason is correct and the assertion is wrong
(c) Both assertion and reason is correct
(d) Both assertion and reason is wrong
1. Assertion: Bacillus thuringiensis is toxic to many insects.
Reason: It inhibits ion transport in the mid gut.
Answer:
(a) Assertion is correct and reason is wrong

2. Assertion.: Recombinant DNA technology has become successful due to restriction endonucleases present in Eukaryotic cells.
Reason: Restriction endonucleases cut the DNA molecule to form blunt ends.
Answer:
(d) Both assertion and reason is wrong

VI. Answer in a word or sentence:

Question 1.
Name two neurodegenerative disorders.
Answer:
Parkinson’s disease and Alzheimer disease.

Question 2.
Name two chemical mutagens.
Answer:
Mustard gas and nitrous acid.

Question 3.
What is plant breeding?
Answer:
Plant breeding is the art of developing economically important plants with superior quality.

Question 4.
What is the aim of Animal husbandry?
Answer:
The aim of Animal husbandry is to improve the genotypes of animals to make them more useful to the welfare of mankind.

Question 5.
What are exotic species?
Answer:
The process of introducing high yield varieties of plants from one place to another are called as exotic species.

Question 6.
List the two main aspects of hybridization.
Answer:
Combining the characters of two plants in one plant and to utilize hybrid vigour are the two main aspects of hybridization.

Question 7.
What is heterosis?
Answer:
The superiority of the hybrid obtained by cross breeding is called heterosis.

Question 8.
What are plasmids?
Answer:
Circular, self-replicating, extra chromosomal DNA in bacteria.

Question 9.
What is transgene?
Answer:
A gene which is transferred from one organism into another organism by genetic engineering.

Question 10.
Name the Research institute found by Nammalvar.
Answer:
Nammalvar ecological foundation for farm research and global food security trust.

VII. Short Answers Questions:

Question 1.
List out the pest-resistant crop varieties.
Answer:

Question 2.
What does the nutritional quality of crop depend on?
Answer:
The nutritional quality of crops depends on the quality and quantity of nutrients.
The nutritional quality may be improved with respect to its:

• Protein content and quality of proteins.
• Oil content.
• Mineral content.

Question 3.
Write a note on Gamma Garden.
Answer:
Gamma garden or Atomic garden is a concept popularised after World War -II for the peaceful use of atomic energy for crop improvement. This is a type of induced mutation breeding where radioactive sources particularly gamma rays from Cobalt-60 or Caesium-137 are used to induce desirable mutations in crop plants.

Question 4.
An organism having more than two sets of chromosomes is called polyploid. It can be induced by physical agents such as heat or cold treatment, X-rays and chemical agents like colchicine.
Answer:
Achievements of polyploidy breeding:

• Seedless watermelons (3n) and bananas (3n).
• TV – 29 (triploid variety of tea) with larger shoots and drought tolerance.
• Triticale (6n) is a hybrid of wheat and rye: It has higher dietary fibre and protein.
• Rapuano brassica is an allotetraploid by colchicine treatment.

Question 5.
Mention the two important properties of stem cells.
Answer:

1. Its ability to divide and give rise to more stem cells by self-renewal.
2. Its ability to give rise to specialised cells with specific functions by the process of differentiation.

Question 6.
Illustrate hybridization with example.
Answer:
Triticale is the first man made cereal hybrid. It is obtained by crossing wheat Triticum durum (2n = 28) and rye (secale cereal, 2n = 14)
Parent Tritium durum × Secale cereal

VIII. Long Answer Questions:

Question 1.
Explain the following methods of plant breeding for crop improvement.
Answer:
(a) Introduction of new varieties in plants:
The process of introducing high yielding varieties of plants from one place to another is called exotic species. These imported plants may carry pathogens and pests. It should be thoroughly checked before introducing to the fields, eg. Phaseolus mungo was introduced from China.

(b) Selection:
Selection is a type of plant breeding, in which individual plants or group of plants are sorted out from a mixed population based on the morphological characters.

Methods of selection:
(i) Mass selection:
Seeds of plants with desired characters are collected from a mixed population. The collected seeds are allowed to raise the second generation. This process is carried out for seven or eight generations. In the end, they are distributed to the farmers for cultivation, eg. TMV – 2 and AK – 10 (groundnut varieties).

(ii) Pure line selection:
Pureline is the “progeny of a single individual obtained by self breeding”. This is also called as individual plant selection. In pure line selection, large numbers of plants are selected from a self – pollinated crop and harvested individually. Progeny is similar, both genotypically and phenotypically.

(iii) Clonal selection:
A group of plants produced from a single plant through vegetative or asexual reproduction are called clones. All the plants of a clone are similar both in genotype and phenotype. Selection of desirable clones from the mixed population of the vegetatively propagated crop is called clonal selection.

Question 2.
In what way trans organism are better?
Answer:
Plants or animals expressing a modified endogenous gene or a foreign gene are also known as transgenic organisms.

The transgenic plants are much stable, with improved nutritional quality, resistant to diseases and tolerant to various environment conditions. Similarly transgenic animals are used to produce proteins of medicinal importance at low cost and improve livestock quality.

Question 3.
Describe the tools of recombinant DNA technology.
Answer:
Techniques of Genetic Engineering – Basic Requirements:
Important discoveries that led to the stepping stone of rDNA technology were

1. Presence ofplasmid in bacteria that can undergo replication independently along with chromosomal DNA.
2. Restriction enzymes cuts or break DNA at specific sites and are also called as molecular scissors.
3. DNA ligases are the enzymes which help in ligating (joining) the broken DNA fragments.

Question 4.
Give the Schematic representation of Mass selection.
Answer:

Mass selection : Seeds of best plants showing desired characters are collected from a mixed population. The collected seeds are allowed to raise the second generation. This process is carried out for seven or eight generations. At the end, they will be multiplied and distributed to the farmers for cultivation. Some common examples for mass selection are groundnut varieties like TMV-2 and AK-10. Its schematic representation is given below.

IX. Higher Order Thinking Skills: (HOTS)

Question 1.
Although ‘green revolution’ increases the food production, it is not enough to feed growing population. This probelm is overcomed by ‘X’ crops.
(a) What is ‘X’?
(b) Explain it with examples.
Answer:
(a) ‘X’ is Genetically modified crops.
(b) Genetic modification refers to the manipulation of genes in the organism using rDNA techniques to produce desired character.

Question 2.
What is Gamma garden?
Answer:
In gamma garden or atomic garden, a type of induced mutation breeding, where radioactive sources, particularly gamma rays from Cobalt – 60 or Caesium – 137 are used to induce desirable mutations in crop plants.

Students can Download Samacheer Kalvi 10th Maths Model Question Paper 4 English Medium Pdf, Samacheer Kalvi 10th Maths Model Question Papers helps you to revise the complete Tamilnadu State Board New Syllabus, helps students complete homework assignments and to score high marks in board exams.

Tamil Nadu Samacheer Kalvi 10th Maths Model Question Paper 4 English Medium

Instructions

• The question paper comprises of four parts.
• You are to attempt all the parts. An internal choice of questions is provided wherever applicable.
• All questions of Part I, II, III and IV are to be attempted separately.
• Question numbers 1 to 14 in Part I are Multiple Choice Quèstions of one-mark each. These are to be answered by choosing the most suitable answer from the given four alternatives and.writing the option code and the corresponding answer.
• Question numbers 15 to 28 in Part II àre two-marks questions. These are to be answered in about one or two sentences.
• Question numbers 29 to 42 in Part III are five-marks questions. These are to be answered in about three to five short sentences.
• Question numbers 43 to 44 in Part IV are eight-marks questions. These are to be answered in detail. Draw diagrams wherever necessary.

Time: 3 Hours
Maximum Marks: 100

PART – I

I. Choose the correct answer. Answer all the questions. [14 × 1 = 14]

Question 1.
If A = {1,2}, B = {1, 2, 3, 4}, C = {5,6} and D = {5, 6, 7, 8} then state which of the following statement is true ………….. .
(1) (A × C) ⊂ (B × D)
(2) (B × D) ⊂ (A × C)
(3) (A × B) ⊂ (A × D)
(4) (D × A) ⊂ (B × A)
Answer:
(1) (A × C) ⊂ (B × D)

Question 2.
If f(x) = 2x² and g(x) = \(\frac { 1 }{ 3x }\), then jog is ………….. .
(1) \(\frac{3}{2 x^{2}}\)
(2) \(\frac{2}{3 x^{2}}\)
(3) \(\frac{2}{9 x^{2}}\)
(4) \(\frac{1}{6 x^{2}}\)
Answer:
(3) \(\frac{2}{9 x^{2}}\)

Question 3.
Given F₁ = 1,F₂ = 3 and F_n = F_n-1 + F_n-2  then F₅ is ………….. .
(1) 3
(2) 5
(3) 8
(4) 11
Answer:
(4) 11

Question 4.
The value of (1³ + 2³ + 3³ +. . . .+ 15³) – (1 + 2 + 3 +….+ 15) is ………….. .
(1) 14400
(2) 14200
(3) 14280
(4) 14520
Answer:
(3) 14280

Question 5.
The solution of the system x + y – 3z = -6 , – 7y + 7z = 7, 3z = 9 is ………….. .
(1) x = 1, y = 2, z = 3
(2) x = -1, y = 2, z = 3
(3) x = -1, y = -2, z = 3
(4) x = 1, y = 2, z = 3
Answer:
(1) x = 1, y = 2, z = 3

Question 6.
If number of columns and rows are not equal in a matrix then it is said to be a ………….. .
(1) diagonal matrix
(2) rectangular matrix
(3) square matrix
(4) identity matrix
Answer:
(2) rectangular matrix

Question 7.
The slope of the line which is perpendicular to a line joining the points (0, 0) and (-8, 8) is ………….. .
(1) -1
(2) 1
(3) \(\frac { 1 }{ 3 }\)
(4) -8
Answer:
(2) 1

Question 8.
If sin θ + cos θ = a and sec θ + cosec θ = 6, then the value of b (a² – 1} is equal to ………….. .
(1) 2 a
(2) 3 a
(3) 0
(4) 2 ab
Answer:
(1) 2 a

Question 9.
If two solid hemispheres of same base radius r units are joined together along their bases, then curved surface area of this new solid is ………….. .
(1) 4π r² sq. units
(2) 6π r² sq. units
(3) 3π r² sq. units
(4) 8π r² sq. units
Answer:
(1) 4π r² sq. units

Question 10.
The standard deviation of a data is 3. If each value is multiplied by 5 then the new variance is ………….. .
(1) 3
(2) 15
(3) 5
(4) 225
Answer:
(4) 225

Question 11.
Kamalam went to play a lucky draw contest. 135 tickets of the lucky draw were sold. If the probability of Kamalam winning is \(\frac { 1 }{ 9 }\), then the number of tickets bought by Kamalam is ………….. .
(1) 5
(2) 10
(3) 15
(4) 20
Answer:
(3) 15

Question 12.
If α and β are the zeros of the polynomial p(x) = 4x² + 3x + 7 then \(\frac{1}{\alpha}+\frac{1}{\beta}\) is equal to …… .
(1) \(\frac{7}{3}\)
(2) \(-\frac{7}{3}\)
(3) \(\frac{3}{7}\)
(4) \(-\frac{3}{7}\)
Answer:
(4) \(-\frac{3}{7}\)

Question 13.
The common ratio of the G.P. a^m-n, a^m, a^{m + n} is ………….. .
(1) a^m
(2) a^-m
(3) aⁿ
(4) aⁿ
Answer:
(3) aⁿ

Question 14.
If the circumference at the base of a right circular cone and the slant height are 120π cm and 10 cm respectively, then the curved surface area of the cone is equal to ………….. .
(1) 1200 π cm²
(2) 600 π cm²
(3) 300 π cm²
(4) 600 π m²
Answer:
(2) 600 π cm²

PART – II

II. Answer any ten questions. Question No. 28 is compulsory. [10 × 2 = 20]

Question 15.
Let A = {1,2, 3, 4} and B = N . Let f: A → B be defined by f(x) = x³ then,
(i) find the range of f
(ii) identify the type of function
Answer:
A = {1,2,3,4}
B = (1,2,3,4,5, ………}
f(x) = x³
f(1) = 1³ = 1
f(2) = 2³ = 8
f(3) = 3³ = 27
f(4) = 4³ = 64
(i) Range = {1, 8,27, 64)
(ii) one -one and into function.

Question 16.
If f(x) = 2x -1, g (x) = \(\frac{x+1}{2}\), show that fog = gof = x
Answer:
f(x) = 2x – 1 : g(x) = \(\frac{x+1}{2}\)
fog = f[g(x)]
= \(f\left[\frac{x+1}{2}\right]\)
= \(2\left(\frac{x+1}{2}\right)-1\)
= x + 1 – 1
= x

gof = g[f(x)]
= g (2x – 1)
= \(\frac{2 x-1+1}{2}\)
= \(\frac{2 x}{2}\)
= x
∴ fog = gof = x
Hence it is proved.

Question 17.
Determine the general term of an A.P. whose 7^th term is -1 and 16^th term is 17.
Answer:
Let the AP. be t₁, t₂, t₃, t₄, ………
It is given that t₇ = -1 and t₁₆ = 17
a + (7 – 1)d = -1 and a + (16 – 1) d = 17
a + 6d = – 1 ……. (1)
a + 15d = 17 ……… (2)
Subtracting equation (1) from equation (2), we get 9d = 18 ⇒ d = 2
Putting d = 2 in equation (1), we get a + 12 = -1 So, a = -13
Hence, general term t_n = a + (n – 1) d = -13 + (n – 1) × 2 = 2n – 15

Question 18.
Find x so that x + 6, x + 12 and x + 15 are consecutive terms of a Geometric Progression.
Answer:
\(\frac{t_{2}}{t_{1}}=\frac{x+12}{x+6}\), \(\frac{t_{3}}{t_{2}}=\frac{x+15}{x+12}\)
Since it is a G.P.
\(\frac{x+12}{x+6}=\frac{x+15}{x+12}\)
(x + 12)² = (x + 6) (x + 15)
x² + 24x + 144 = x² + 21x + 90
3x = -54 ⇒ x = \(\frac{-54}{3}\) = – 18

Question 19.
Find the excluded values of the expression \(\frac{x^{2}+6 x+8}{x^{2}+x-2}\)
Answer:
x² + 6x + 8 = (x + 4)(x + 2)
x² + x – 2 = (x + 2)(x – 1)


The expression \(\frac{x+4}{x-1}\) is undefined
when x – 1 = 0 ⇒ x = 1
The excluded value is 1

Question 20.
Solve 3p² + 2√5p – 5 = 0 by formula method.
Answer:
Compute 3p² + 2√5p – 5 = 0 with the standard form ax² + bx + c = O
a = 3, b = 2√5, c = -5
p = \(\frac{-b \pm \sqrt{b^{2}-4 a c}}{2 a}\)
Substituting the values of a, b and e in the formula we get,

Therefore, x = \(\frac{\sqrt{5}}{3},-\sqrt{5}\)

Question 21.
Write the expression \(\frac{\alpha+3}{\beta}+\frac{\beta+3}{\alpha}\) in terms of α + β and αβ.
Answer:

Question 22.
Rhombus PQRB is inscribed in ∆ABC such that ∠B is one of its angle. P, Q and R lie on AB, AC and BC respectively. If AB = 12 cm and BC = 6 cm, find the sides PQ, RB of the rhombus.
Answer:
Let the side of the rhombus be “x”. Since PQRB is a Rhombus PQ || BC
By basic proportionality theorem
\(\frac{A P}{A B}=\frac{P Q}{B C} \Rightarrow \frac{12-x}{12}=\frac{x}{6}\)
12x = 6(12 – x)
12x = 72 – 6x
12x + 6x = 72
18x = 72 ⇒ x = \(\frac { 72 }{ 18 }\) = 4
Side of a rhombus = 4cm
PQ = RB = 4cm

Question 23.
Find the equation of a straight line which is parallel to the line 3x – 7y = 12 and passing through the point (6,4)
Answer:
Equation of the straight line, parallel to 3x – 7y – 12 = 0 is 3x – 7y + k= O
Since it passes through the point (6,4)
3(6) – 7(4) + k = 0
k = 28 – 18= 10
Therefore, equation of the required straight line is 3x – 7y + 10 = 0.

Question 24.
Prove that \(\frac{\tan ^{2} \theta-1}{\tan ^{2} \theta+1}\) = 1 – 2 cos² θ
Answer:

= sin² θ – cos² θ = 1 – cos² θ – cos² θ
= 1 – 2 cos²θ
L.H.S = R.H.S
Hence it is proved.

Question 25.
The standard deviation and coefficient of variation of a data are 1.2 and 25.6 respectively. Find the value of mean.
Answer:
Standard deviation (σ) = 1.2
Coefficient of variation = 25.6
\(\frac{\sigma}{x} \times 100\) = 25.6
\(\frac{1.2}{\bar{x}} \times 100\) = 25.6 ⇒ 25.6 × x̄ = 1.2 × 100
x̄ = \(\frac{120}{25.6}=\frac{120 \times 10}{256}\) = 4.687 = 4.69
Value of mean = 4.69

Question 26.
Three dice are thrown simultaneously. Find the probability of getting the same number.
Answer:
Sample space = {(1, 1, 1) (1, 1,2) (1, 1,3). .. . (6,6, 6)}
n(S) = 216
Let A be the event of getting the same number on all the three dice
A = {(1,1,1),(2,2,2),(3,3,3),(4,4,4)(5,5,5)(6,6,6fl
n(A) = 6
P(A) = \(\frac{n(\mathrm{A})}{n(\mathrm{S})}=\frac{6}{216}=\frac{1}{36}\)

Question 27.
If the curved surface area of a solid hemisphere is 2772 sq. cm, then find its total surface area.
Answer:
Curved surface area ofa hemisphere = 2772 sq.cm
2πr² = 2772
πr² = \(\frac{2772}{2}\) = 1386
T.S.A of the hemisphere = 3πr² sq. units
= 3 × 1386 cm²
= 4158 cm²

Question 28.
Which term of the geometric sequence 5,2, \(\frac{4}{5}, \frac{8}{25} \cdots \text { is } \frac{128}{15625}\) ?
Answer:
The given G.P is 5,2, \(\frac{4}{5}, \frac{8}{25} \cdots \text { is } \frac{128}{15625}\)
Here a = 5, r = \(\frac { 2 }{ 5 }\)
t_n = \(\frac{128}{15625}\)
a.r_n-a = \(\frac{128}{15625}\)

PART – III

III. Answer any ten questions. Question No. 42 is compulsory. [10 × 5 = 50]

Question 29.
Let f: A → B be a function defined by f(x) = \(\frac { x }{ 2 }\) – 1, where A = {2,4,6,10,12}, B = {0,1,2,4,5,9} . Represent f by
(i) set of ordered pairs
(ii) a table
(iii) an arrow diagram
(iv) a graph
Answer:
(i) f = {(2,0)(4, 1)(6,2)(10,4)(12,5)

(ii)

(iii)

(iv)

Question 30.
Given f(x) = x – 1, g(x) = 3x + 1 and h(x) = x² show that (fog)oh = fo(goh)

Question 31.
The product of three consecutive terms of a Geometric Progression is 343 and their sum is \(\frac{91}{3}\) Find the three terms.

Question 32.
Find the sum of all natural numbers between 602 and 902 which are not divisible by 4?

Question 33.
There are 12 pieces of five, ten and twenty rupee currencies whose total value is ₹105. But when first 2 sorts are interchanged in their numbers its value will be increased by ₹20. Find the number of currencies in each sort.

Question 34.
A passenger train takes 1 hr more than an express train to travel a distance of 240 km from Chennai to Virudhachalam. The speed of passenger train is less than that of an express train by 20 km per hour. Find the average speed of both the trains.

Question 35.
ABCD is a trapezium in which AB || DC and P,Q are points on AD and BC respectively, such that PQ || DC if PD = 18 cm, BQ = 35 cm and QC = 15 cm, find AD.

Question 36.
Find the equation of the perpendicular bisector of the line joining the points A(-4,2) and B(6, -4).

Question 37.
From the top of a tower 50 m high, the angles of depression of the top and bottom of a tree and observed to be 30° and 45° respectively. Find the height of the tree. ( √3 = 1.732)

Question 38.
A hemispherical bowl is filled to the brim with juice. The juice is poured into a cylindrical vessel whose radius is 50% more than its height. If the diameter is same for both the bowl and the cylinder then find the percentage of juice that can be transferred from the bowl into the cylindrical 1 vessel.

Question 39.
A box contains cards numbered 3, 5, 7,9,… 35,37. A card is drawn at random from the box. Find the probability that the drawn card have either multiples of 7 or a prime number.

Question 40.
The function f: [-7, 6] → R is defined as follows.

Question 41.
The denominator of a fraction is 4 more than twice the numerator. When both the numerator and denominator are decreased by 6, then the denominator becomes 12 times the numerator determine the fraction.

Question 42.
If for distribution Σx – 7 = 3 ; (Σx – 7)² = 57 and total number of the item is 20; find the mean and standard deviation.

PART – IV

IV. Answer all the questions. [2 × 8 = 16]

Question 43.
(a) Draw a circle of diameter 6 cm from a point P, which is 8 cm away from its centre. Draw the two tangents PA and PB to the circle and measure their lengths.

[OR]

(b) Construct a triangle ∆PQR such that QR = 5 cm, ∠P = 30° and the altitude from P to QR is of length 4.2 cm.

Question 44.
(a) Draw the graph of y = x² and hence solve x² – 4x – 5 = 0.

[OR]

(b) Draw the graph of y = x² + 3x + 2 and use it to solve the equation x² + 2x + 4 = 0.

Students can download 10th Science Chapter 19 Origin and Evolution of Life Questions and Answers, Notes, Samacheer Kalvi 10th Science 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 10th Science Solutions Chapter 19 Origin and Evolution of Life

Samacheer Kalvi 10th Science Origin and Evolution of Life Text Book Back Questions and Answers

I. Choose the correct answer.

Question 1.
Biogenetic law states that:
(a) Ontogeny and phylogeny go together
(b) Ontogeny recapitulates phylogeny
(c) Phylogeny recapitulates ontogeny
(d) There is no relationship between phylogeny and ontogeny
Answer:
(b) Ontogeny recapitulates phylogeny

Question 2.
The ‘use and disuse theory’ was proposed by:
(a) Charles Darwin
(b) Ernst Haeckel
(c) Jean Baptiste Lamarck
(d) Gregor Mendel
Answer:
(c) Jean Baptiste Lamarck

Question 3.
Paleontologists deal with:
(a) Embryological evidences
(b) Fossil evidences
(c) Vestigial organ evidences
(d) All the above
Answer:
(a) Embryological evidences

Question 4.
The best way of direct dating fossils of recent origin is by:
(a) Radio-carbon method
(b) Uranium lead method
(c) Potassium-argon method
(d) Both (a) and (c)
Answer:
(a) Radio-carbon method

Question 5.
The term Ethnobotany was coined by:
(a) Khorana
(b) J.W. Harshberger
(c) Ronald Ross
(d) Hugo de Vries
Answer:
(b) J.W. Harshberger

II. Fill in the blanks.

1. The characters developed by the animals during their life time, in response to the environmental changes are called ………..
2. The degenerated and non-functional organs found in an organism are called ……….
3. The forelimb of bat and human are examples of ………. organs.
4. The theory of natural selection for evolution was proposed by ………..

Answer:

1. acquired characters
2. vestigial organs
3. homologous
4. Charles Darwin

III. State true or false. Correct the false statements.

1. The use and disuse theory of organs’ was postulated by Charles Darwin.
2. The homologous organs look similar and perform similar functions but they have different origin and developmental pattern.
3. Birds have evolved from reptiles.

Answer:

1. False – The use and disuse theory of organs’ was postulated by Jean Baptiste Lamarck.
2. False – The analogous organs look similar and perform similar functions but they have different origin and developmental pattern.
3. True

IV. Match the following.

Answer:
A. (iii)
B. (i)
C. (iv)
D. (ii)
E. (vi)
F. (v)

V. Answer in a word or sentence.

Question 1.
A human hand, a front leg of a cat, a front flipper of a whale and a bat’s wing look dissimilar and adapted for different functions. What is the name given to these organs?
Answer:
Homologous organ – as they have inherited from common ancestors with similar developmental pattern in embryos.

Question 2.
Which organism is considered to be the fossil bird?
Answer:
Archaeopteryx is the fossil bird, found in the Jurassic period.

Question 3.
Why is Archaeopteryx considered to be a connecting link?
Answer:
Archaeopteryx is considered to be a connecting link between reptiles and birds as it had wings with feathers like a bird and had a long tail, clawed digits and conical teeth like a reptile.

VI. Short Answers Questions

Question 1.
The degenerated wing of a kiwi is an acquired character. Why is it an acquired character?
Answer:
The characters developed by the animals during their life time in response to the environmental changes are called acquired character. The acquired characters are transmitted to the offspring by the process of inheritance.

Question 2.
Why is Archaeopteryx considered to be a connecting link?
Answer:
Archaeopteryx is the oldest known fossil bird. It is considered to be a connecting link between reptiles and birds. It had wings with feathers, like a bird. It had a long tail, clawed digits and conical teeth, like a reptile.

Question 3.
Define Ethnobotany and write its importance.
Answer:
Ethnobotany is the study of a region’s plants and their practical uses through the traditional knowledge of the local culture of people.

Question 4.
How can you determine the age of the fossils?
Answer:
The age of fossils is determined by radioactive elements present in it. The elements may be carbon, uranium, lead or potassium. Carbon consumption of animals and plants stops after death, and the decaying process of C14 occurs continuously. The time passed since the death of a plant or animal can be calculated by measuring the amount of C14 present in their body.

VII. Long Answer Questions

Question 1.
Natural selection is a driving force for evolution-How?
Answer:
Survival of the fittest or Natural selection : During the struggle for existence, the organisms which can overcome the challenging situation, survive and adapt to the surrounding environment. Organisms which are unable to face the challenges, are unfit to survive and disappear. The process of selection of organisms with favourable variation is called as natural selection.

Question 2.
How do you differentiate homologous organs from analogous organs?
Answer:

Question 3.
How does fossilization occur in plants?
Answer:
The process of formation of fossil in the rocks is called Fossilization. The common methods of fossilization include:
1. Petrifaction: Minerals like silica slowly penetrate in and replace the original organic tissue and forms a rock-like fossil. This method of fossilization can preserve hard and soft parts mostly bones and wood fossils are petrified.

2. Mould and cast: A replica of a plant or animal is preserved in sedimentary rocks. When the organism gets buried in sediment it is dissolved by underground water leaving a hollow depression called a mould. It shows the original shape but does not reveal the internal structure. Minerals or sediment fill the hollow depression and form a cast.

3. Preservation: Original remains can be preserved in ice or amber (tree sap). They protect the organisms from decay. The entire plant or animal is preserved.

4. Compression: When an organism dies, the hard parts of their bodies settle at the bottom of the sea bed and are covered by sediment. The process of sedimentation goes on continuously and fossils are formed.

5. Infiltration or Replacement: The precipitation of minerals takes place which later on infiltrates the cell wall. The process is brought about by several mineral elements such as silica, calcium carbonate and magnesium carbonate. Hard parts are dissolved and replaced by these minerals.

VIII. Higher Order Thinking Skills (HOTS).

Question 1.
Arun was playing in the garden. Suddenly he saw a dragon fly sitting on a plant. He observed the wings of it. He thought it looked similar to a wing of a crow. Is he correct? Give reason for your answer.
Answer:
No. Arun is not correct. It is called as Analogous organ. They look similar and perform similar functions, but they have different origin and developmental pattern.

Question 2.
Imprints of fossils tell us about evolution-How?
Answer:
Fossils provide solid evidence that organisms from the past are not the same as those found today. Fossils show a progression of evolution by comparing the anatomical record of fossils with modem and extinct species. Palaeontologist can infer the linkages of their species. For this the body parts such as shell bones or teeth are used. The resulting fossil record tells the story of the part and show the evolution of form over millions of years.

Question 3.
Octopus, cockroach and frog all have eyes. Can we group these animals together to establish a common evolutionary origin. Justify your answer.
Answer:
No, we cannot group these animals together because development of eye is not a point utilised in classification as well as in evolution.

Samacheer Kalvi 10th Science Origin and Evolution of Life Additional Important Questions and Answers

I. Choose the correct answer.

Question 1.
Life originated in:
(a) Air
(b) Earth
(c) Water
(d) Nitrogen
Answer:
(c) Water

Question 2.
Believers of spontaneous generation theory believed that:
(a) Life originated from a similar organism
(b) Life originated from the air
(c) Life originated only spontaneously
(d) Life originated from pre-existing life
Answer:
(c) Life originated only spontaneously

Question 3.
Which of the following organ in man is not vestigial?
(a) Vermiform appendix
(b) Nictitating membrane
(c) Ear muscles
(d) Epiglottis
Answer:
(a) Vermiform appendix

Question 4.
Analogous organs are:
(a) similar in origin
(b) similar in structure
(c) non-functional
(d) similar in function
Answer:
(b) similar in structure

Question 5.
Wings of locust, pigeon and bat are example of:
(a) Vestigial organs
(b) Analogous organs
(c) Homologous organs
(d) Evolution
Answer:
(a) Vestigial organs

Question 6.
The distance needs to be neither too hot nor too cold is called ______.
(a) habitable zone
(b) Goldilock zone
(c) Aquatic zone
(d) Terrestrial zone.
Answer:
(c) Aquatic zone

Question 7.
Fossils are dated by:
(a) Amount of calcium residue
(b) Amount of radio active carbon compound
(c) Association with other mammals
(d) Structure of bones
Answer:
(b) Amount of radio active carbon compound

Question 8.
A basket of vegetables contains carrot, potato and tomato. Which of them represent the correct homologous structures?
(a) Carrot and potato
(b) Carrot and tomato
(c) Radish and carrot
(d) Radish and potato
Answer:
(c) Radish and carrot

Question 9.
Most fossil have been found in:
(a) Black soil
(b) Lava flows
(c) Granite
(d) Sedimentary rocks
Answer:
(d) Sedimentary rocks

Question 10.
Birbal sahni was a:
(a) Zoologist
(b) Lounder of Central Drug Research Institute
(c) Ornithologist
(d) Palaeobotanist
Answer:
(d) Palaeobotanist

Question 11.
Darwin in his ‘Natural Selection Theory’ did not believe in any role of which one of the following in organic evolution.
(a) Parasites and Predators as natural enemies
(b) Survival of the fittest
(c) Struggle for existence
(d) Discontinuous Variation
Answer:
(d) Discontinuous Variation

Question 12.
Fossilizaticn can occur in:
(a) Animals are burned and preserved by natural process
(b) Animals are destroyed by scavangers
(c) Animals are eaten by predators
(d) Animals are destroyed by environmental conditions
Answer:
(a) Animals are burned and preserved by natural process

II. Fill in the blanks.

1. Branch of biology which deals with fossils is …………
2. Archaeopteryx is connecting link between reptiles and ………..
3. Darwin explained origin of species through …………
4. The ship on which Darwin worked as naturalist was …………
5. The book Origin of Species was published in the year …………
6. Mutation can be artificially induced by ………..
7. Extraterrestrial states that units of life called ………..
8. The idea of chemical evolution of life was developed by …………..
9. Living being able to reproduce more individuals and form the own progeny is called …………..
10. ……….. is the raw material which plays an important role in evolution.
Answer:
1. Palaeontology
2. Birds
3. Natural selection
4. H.M.S. Beagle
5.1859
6. Radiation
7. Panspermia (spores)
8. Oparin and Haldane
9. Over production
10. Variation

III. Match the following.

Answer:
A. (ii)
B. (iv)
C. (i)
D. (v)
E. (iii)

IV. State whether True or false. If false write the correct statement.

1. De Vries is called as the Father of Palaeontology.
2. NASA is developing the Mars 2020 astrobiology to investigate an astrobiologically details of Mars.
3. Competition among the individual of same species is Interspecific struggle.
4. Abiogenesis states that life originates from pre existing life.
5. The Big Bang theory explains the origin of Universe.

Answer:

1. False – Leonardo da vinci is called as the Father of Palaeontology.
2. True
3. False – Competition among the individual of same species is Intraspecific struggle.
4. False – Biogenesis states that life originates from pre existing life.
5. True

V. Answer in a word or sentence.

Question 1.
Who proposed the theory of Natural selection?
Answer:
Charles Darwin

Question 2.
What do you understand by evolution?
Answer:
Formation of new species due to changes in specific characters over several generations as response to natural selection is called evolution.

Question 3.
How do embryological studies provide evidences for evolution?
Answer:
The embryos from fish to mammals are similar in their early stages of development. The differentiation of their special characters appear in the later stages of development.

Question 4.
Mention three important features of fossils.
Answer:

1. Fossils are useful in classification of organisms.
2. Fossils are used in the field of descriptive and comparative analoms.
3. Fossils throw light on phylogeny and evolution of organisms.

Question 5.
Who is the Father of Indian Paleobotany? What is his contribution in this field.
Answer:
Birbal Sahani is the Father of Indian Paleobotany. He presented his research on two different areas of Paleobotany.

1. The anatomy and morphology of paleozoic ferns.
2. The fossil plants of the Indian Gondwana formation.

Question 6.
List out the methods of Fossilization.
Answer:
Common methods of fossilization includes petrifaction molds and cast, carbonization preservation, compression and infiltration.

Question 7.
What are extremophiles?
Answer:
The organisms which live in extreme environmental conditions on earth are called extremophiles.

Question 8.
What is Goldilock zone for life. Name the planet in the Goldilock zone.
Answer:
The Goldilock zone for life is the zone having a right mass to retain an atmosphere and have an orbit at the right distance from its star that allows liquid water to exist and the distance need to be neither too hot or cold. In our solar system – Earth is the only planet in the Goldilock zone.

Question 9.
What are the three types of struggle for existence?
Answer:

1. Intra specific struggle
2. Inter specific struggle
3. Environmental struggle

Question 10.
What is Atavism?
Answer:
The appearance of the ancestral character in some individuals is called Atavism. Eg: Presence of rudimentary tail in newborn babies.

VI. Short Answer Questions.

Question 1.
Distinguish between acquired and inherited trait with example.
Answer:

Question 2.
What are the aspects of ethnobotany?
Answer:
Ethnobotany has relevance with problems of nutrition, health care and life support system, faith in plants, cottage industries, economic upliftment, conservation of biodiversity and sustainable use of plant resources.

Question 3.
What is the Geological Time Scale?
Answer:
The geological time scale is a system of chronological dating that relates geological rock strata to time and is used by geologists, palaeontologists and other Earth scientists to describe the timing and relationships of events that have occurred during Earth’s history.

Question 4.
Write a note on types of Germinal Variation.
Answer:
Germinal variation are classified into two types:

1. Continuous variation,
2. Discontinuous variation

1. Continuous variation : These are small variations which occur among individuals of a population. They are also called as fluctuating variations. They occur by gradual accumulation in a population, e.g. skin colour, height and weight of an individual, colour of eye, etc.

2. Discontinuous variation : These are sudden changes which occur in an organism due to mutations. They do not have any intermediate forms. These large variations are not useful for evolution, e.g. short legged Ancon sheep, six or more digits (fingers) in human, etc.

Question 5.
Explain the existence for astro biology.
Answer:
The theory explains that any planets can support the existence of life, if it fulfills two important criteria.

1. It must have a right mass to retain an atmosphere.
2. It must have an orbit at just the right distance from its star (Sun) that it allows liquid water to exist. Thus, the distance need to be neither too hot or not too cold and is often referred as Goldilock Zone for life.

VII. Long Answer Questions.

Question 1.
Explain the various methods of Fossilization.
Answer:
Common methods of fossilization includes petrifaction, molds and cast, carbonization, preservation, compression and infiltration.
Petrifaction : Minerals like silica slowly penetrate in and replace the original organic tissue and forms a rock like fossil. This method of fossilization can preserve hard and soft parts. Most bones and wood fossils are petrified.

Mold and Cast : A replica of a plant or animal is preserved in sedimentary rocks. When the organism gets buried in sediment it is dissolved by underground water leaving a hollow depression called a mold. It shows the original shape but does not reveal the internal structure. Minerals or sediment fill the hollow depression and forms a cast.

Preservation : Original remains can be preserved in ice or amber (tree sap). They protect the organisms from decay. The entire plant or animal is preserved.

Compression : When an organism dies, the hard parts of their bodies settle at the bottom of the sea bed and are covered by sediment. The process of sedimentation goes on continuously and fossils are formed.

Infiltration or Replacement : The precipitation of minerals takes place which later on infiltrate the cell wall. The process is brought about by several mineral elements such as silica, calcium carbonate and magnesium carbonate. Hard parts are dissolved and replaced by these minerals.

Question 2.
Explain the principles of Lamarckism.
Answer:
Principles of Lamarckism:
(i) Internal vital force : Living organisms or their component parts tend to increase in size continuously. This increase in size is due to the inherent ability of the organisms.

(ii) Environment and new needs : A change in the environment brings about changes in the need of the organisms. In response to the changing environment, the organisms develop certain adaptive characters. The adaptations of the organisms may be in the form of development of new parts of the body.

(iii) Use and disuse theory : Lamarck’s use and disuse theory states that if an organ is used constantly, the organ develops well and gets strengthened. When an organ is not used for a long time, it gradually degenerates.

The ancestors of giraffe were provided with short neck and short – forelimbs. Due to shortage of grass, they were forced to feed on leaves from trees. The continuous stretching of their neck and forelimbs resulted in the development of long neck and long forelimbs which is an example for constant use of an organ. The degenerated wing of Kiwi is an example for organ of disuse.

(iv) Theory of Inheritance of acquired characters : When there is a change in the environment, the animals respond to the change. They develop adaptive structures. The characters developed by the animals during their life time, in response to the environmental changes are called acquired characters. According to Lamarck, the acquired characters are transmitted to the offspring by the process of inheritance.

VIII. Higher Order Thinking Skills (HOTS).

Question 1.
What is the relationship between mutation and variation?
Answer:
Mutation and variation are the two events involved in the process of evolution. Mutation arises due to errors occurring in DNA during replication or exposure to ultraviolet rays or chemicals. The mutation leads to variation. It brings about changes in a single individual.

Question 2.
Picture of the newborn baby to be given.

(i) Name the phenomenon responsible for the structure marked (a) in the Figure.
Answer:
Atavism

(ii) Give the definition of the phenomenon responsible for the development for the structure marked.
Answer:
The reappearance, ancestral character in some individuals.