Class 10 Science Answer Sheet for 2024 | Science Class 10 PDF Download

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SCIENCE 
CBSE Class-X (2024) 
Answers & Solutions
GENERAL INSTRUCTIONS 
Read the following instructions very carefully and strictly follow them : 
(i) This question paper comprises 39 questions. All questions are compulsory. 
(ii) The question paper is divided into FIVE sections – A, B, C, D and E.  
(iii) Section-A - Question Nos. 1 to 20 are multiple choice questions (MCQs). Each question carries 1 mark. 
(iv) Section-B - Question Nos. 21 to 26 are very short answer (VSA) type questions. Each question carries 2 marks. 
Answer to these questions should be in the range of 30 to 50 words. 
(v) Section-C - Question Nos. 27 to 33 are short answer (SA) type questions. Each question carries 3 marks. Answer to 
these questions should be in the range of 50 to 80 words. 
(vi) Section-D - Question Nos. 34 to 36 are long answer (LA) type questions. Each question carries 5 marks. Answer to 
these questions should be in the range of 80 to 120 words. 
(vii) Section-E - Question Nos. 37 to 39 are of 3 source-based/case-based units of assessment carrying 4 marks each 
with sub-parts. 
(viii) There is no overall choice. However, an internal choice has been provided in some sections. Only one of the 
alternatives has to be attempted in such questions. 
  
Date: 02/03/2024 
Time: 3 Hours Max. Marks: 80 
Question Paper Code 
31/1/3 
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- 1 - 
 
 
SCIENCE 
CBSE Class-X (2024) 
Answers & Solutions
GENERAL INSTRUCTIONS 
Read the following instructions very carefully and strictly follow them : 
(i) This question paper comprises 39 questions. All questions are compulsory. 
(ii) The question paper is divided into FIVE sections – A, B, C, D and E.  
(iii) Section-A - Question Nos. 1 to 20 are multiple choice questions (MCQs). Each question carries 1 mark. 
(iv) Section-B - Question Nos. 21 to 26 are very short answer (VSA) type questions. Each question carries 2 marks. 
Answer to these questions should be in the range of 30 to 50 words. 
(v) Section-C - Question Nos. 27 to 33 are short answer (SA) type questions. Each question carries 3 marks. Answer to 
these questions should be in the range of 50 to 80 words. 
(vi) Section-D - Question Nos. 34 to 36 are long answer (LA) type questions. Each question carries 5 marks. Answer to 
these questions should be in the range of 80 to 120 words. 
(vii) Section-E - Question Nos. 37 to 39 are of 3 source-based/case-based units of assessment carrying 4 marks each 
with sub-parts. 
(viii) There is no overall choice. However, an internal choice has been provided in some sections. Only one of the 
alternatives has to be attempted in such questions. 
  
Date: 02/03/2024 
Time: 3 Hours Max. Marks: 80 
Question Paper Code 
31/1/3 
  
SECTION-A 
Multiple Choice Type Questions : [16×1=16] 
Select and write the most appropriate option out of the four options given for each of the questions 1-20. 
There is no negative mark for the incorrect response. 
1. Select from the following a decomposition reaction in which source of energy for decomposition is light: [1] 
 (a) 2FeSO4 ? Fe2O3 + SO2 + SO3 (b) 2H2O ? 2H2 + O2 
 (c) 2AgBr ??2Ag + Br2 (d) CaCO3 ? CaO + CO2 
Answer (c)   [1] 
Sol. 
Heat
42323
2FeSO Fe O SO SO ?? ? ? ? ? 
 
Electric current
222
2H O 2H O ????? ???? 
 
Sunlight
2
2AgBr 2Ag Br ?? ? ? ??? 
 
Heat
32
CaCO CaO CO ?? ? ? ? 
2. When 2 mL of sodium hydroxide solution is added to few pieces of granulated zinc in a test tube and then 
warmed, the reaction that occurs can be written in the form of a balanced chemical equation as: [1] 
 (a) NaOH + Zn ? NaZnO2 + H2O (b) 2NaOH + Zn ? Na2ZnO2 + H2 
 (c) 2NaOH + Zn ? NaZnO2 + H2 (d) 2NaOH + Zn ? Na2ZnO2 + H2O 
Answer (b)   [1] 
Sol. When zinc reacts with sodium hydroxide solution, sodium zincate and hydrogen gas are produced. 
 
22 2
2NaOH Zn Na ZnO H ????? 
3. MnO2 + 4HCl ? MnCl2 + 2H2O + Cl2 [1] 
 The reaction given above is a redox reaction because in this case : 
 (a) MnO2 is oxidised and HCl is reduced (b) HCl is oxidised 
 (c) MnO2 is reduced (d) MnO2 is reduced and HCI is oxidised 
Answer (d)   [1] 
Sol.  
4. Consider the following compounds : 
 FeSO4; CuSO4; CaSO4; Na2CO3 
 The compound having maximum number of water of crystallisation in its crystalline form in one molecule is : [1] 
 (a) FeSO4 (b) CuSO4 
 (c) CaSO4 (d) Na2CO3 
Answer (d)   [1] 
Page 3


- 1 - 
 
 
SCIENCE 
CBSE Class-X (2024) 
Answers & Solutions
GENERAL INSTRUCTIONS 
Read the following instructions very carefully and strictly follow them : 
(i) This question paper comprises 39 questions. All questions are compulsory. 
(ii) The question paper is divided into FIVE sections – A, B, C, D and E.  
(iii) Section-A - Question Nos. 1 to 20 are multiple choice questions (MCQs). Each question carries 1 mark. 
(iv) Section-B - Question Nos. 21 to 26 are very short answer (VSA) type questions. Each question carries 2 marks. 
Answer to these questions should be in the range of 30 to 50 words. 
(v) Section-C - Question Nos. 27 to 33 are short answer (SA) type questions. Each question carries 3 marks. Answer to 
these questions should be in the range of 50 to 80 words. 
(vi) Section-D - Question Nos. 34 to 36 are long answer (LA) type questions. Each question carries 5 marks. Answer to 
these questions should be in the range of 80 to 120 words. 
(vii) Section-E - Question Nos. 37 to 39 are of 3 source-based/case-based units of assessment carrying 4 marks each 
with sub-parts. 
(viii) There is no overall choice. However, an internal choice has been provided in some sections. Only one of the 
alternatives has to be attempted in such questions. 
  
Date: 02/03/2024 
Time: 3 Hours Max. Marks: 80 
Question Paper Code 
31/1/3 
  
SECTION-A 
Multiple Choice Type Questions : [16×1=16] 
Select and write the most appropriate option out of the four options given for each of the questions 1-20. 
There is no negative mark for the incorrect response. 
1. Select from the following a decomposition reaction in which source of energy for decomposition is light: [1] 
 (a) 2FeSO4 ? Fe2O3 + SO2 + SO3 (b) 2H2O ? 2H2 + O2 
 (c) 2AgBr ??2Ag + Br2 (d) CaCO3 ? CaO + CO2 
Answer (c)   [1] 
Sol. 
Heat
42323
2FeSO Fe O SO SO ?? ? ? ? ? 
 
Electric current
222
2H O 2H O ????? ???? 
 
Sunlight
2
2AgBr 2Ag Br ?? ? ? ??? 
 
Heat
32
CaCO CaO CO ?? ? ? ? 
2. When 2 mL of sodium hydroxide solution is added to few pieces of granulated zinc in a test tube and then 
warmed, the reaction that occurs can be written in the form of a balanced chemical equation as: [1] 
 (a) NaOH + Zn ? NaZnO2 + H2O (b) 2NaOH + Zn ? Na2ZnO2 + H2 
 (c) 2NaOH + Zn ? NaZnO2 + H2 (d) 2NaOH + Zn ? Na2ZnO2 + H2O 
Answer (b)   [1] 
Sol. When zinc reacts with sodium hydroxide solution, sodium zincate and hydrogen gas are produced. 
 
22 2
2NaOH Zn Na ZnO H ????? 
3. MnO2 + 4HCl ? MnCl2 + 2H2O + Cl2 [1] 
 The reaction given above is a redox reaction because in this case : 
 (a) MnO2 is oxidised and HCl is reduced (b) HCl is oxidised 
 (c) MnO2 is reduced (d) MnO2 is reduced and HCI is oxidised 
Answer (d)   [1] 
Sol.  
4. Consider the following compounds : 
 FeSO4; CuSO4; CaSO4; Na2CO3 
 The compound having maximum number of water of crystallisation in its crystalline form in one molecule is : [1] 
 (a) FeSO4 (b) CuSO4 
 (c) CaSO4 (d) Na2CO3 
Answer (d)   [1] 
Sol. 
442
(Green vitriol)
442
(Blue vitriol)
442
(Gypsum)
23 23 2
(Washing soda)
FeSO FeSO 7H O
CuSO CuSO 5H O
CaSO CaSO 2H O
Na CO Na CO 10H O
?
?
?
?
Compound Crystalline form 
5. In a nerve cell, the site where the electrical impulse is converted into a chemical signal is known as: [1] 
 (a) Axon (b) Dendrites 
 (c) Neuromuscular junction (d) Cell body 
Answer (c)   [1] 
Sol. Neuromuscular junction is the site where the electrical impulse is converted into a chemical signal for onward 
transmission. 
6. A metal and a non-metal that exists in liquid state at the room temperature are respectively: [1] 
 (a) Bromine and Mercury (b) Mercury and Iodine 
 (c) Mercury and Bromine (d) Iodine and Mercury 
Answer (c)   [1] 
Sol. Mercury is a metal which exists in liquid state at the room temperature whereas bromine is a non-metal which 
exists in liquid state at the room temperature. 
7. At what distance from a convex lens should an object be placed to get an image of the same size as that of the 
object on a screen? [1] 
 (a) Beyond twice the focal length of the lens 
 (b) At the principal focus of the lens 
 (c) At twice the focal length of the lens 
 (d) Between the optical centre of the lens and its principal focus 
Answer (c)    [1] 
Sol. When object is placed at twice the focal length of a convex lens, an image of the same size as that of the 
object is formed. 
8. Carbon compounds : [1] 
 (i) are good conductors of electricity. 
 (ii) are bad conductors of electricity. 
 (iii) have strong forces of attraction between their molecules. 
 (iv) have weak forces of attraction between their molecules. 
 The correct statements are: 
 (a) (i) and (ii) (b) (ii) and (iii) 
 (c) (ii) and (iv) (d) (i) and (iii) 
Answer (c)   [1] 
Sol. Carbon compounds are bad conductors of electricity as they contain covalent bonds. Force of attraction 
between their molecules are not very strong. 
Page 4


- 1 - 
 
 
SCIENCE 
CBSE Class-X (2024) 
Answers & Solutions
GENERAL INSTRUCTIONS 
Read the following instructions very carefully and strictly follow them : 
(i) This question paper comprises 39 questions. All questions are compulsory. 
(ii) The question paper is divided into FIVE sections – A, B, C, D and E.  
(iii) Section-A - Question Nos. 1 to 20 are multiple choice questions (MCQs). Each question carries 1 mark. 
(iv) Section-B - Question Nos. 21 to 26 are very short answer (VSA) type questions. Each question carries 2 marks. 
Answer to these questions should be in the range of 30 to 50 words. 
(v) Section-C - Question Nos. 27 to 33 are short answer (SA) type questions. Each question carries 3 marks. Answer to 
these questions should be in the range of 50 to 80 words. 
(vi) Section-D - Question Nos. 34 to 36 are long answer (LA) type questions. Each question carries 5 marks. Answer to 
these questions should be in the range of 80 to 120 words. 
(vii) Section-E - Question Nos. 37 to 39 are of 3 source-based/case-based units of assessment carrying 4 marks each 
with sub-parts. 
(viii) There is no overall choice. However, an internal choice has been provided in some sections. Only one of the 
alternatives has to be attempted in such questions. 
  
Date: 02/03/2024 
Time: 3 Hours Max. Marks: 80 
Question Paper Code 
31/1/3 
  
SECTION-A 
Multiple Choice Type Questions : [16×1=16] 
Select and write the most appropriate option out of the four options given for each of the questions 1-20. 
There is no negative mark for the incorrect response. 
1. Select from the following a decomposition reaction in which source of energy for decomposition is light: [1] 
 (a) 2FeSO4 ? Fe2O3 + SO2 + SO3 (b) 2H2O ? 2H2 + O2 
 (c) 2AgBr ??2Ag + Br2 (d) CaCO3 ? CaO + CO2 
Answer (c)   [1] 
Sol. 
Heat
42323
2FeSO Fe O SO SO ?? ? ? ? ? 
 
Electric current
222
2H O 2H O ????? ???? 
 
Sunlight
2
2AgBr 2Ag Br ?? ? ? ??? 
 
Heat
32
CaCO CaO CO ?? ? ? ? 
2. When 2 mL of sodium hydroxide solution is added to few pieces of granulated zinc in a test tube and then 
warmed, the reaction that occurs can be written in the form of a balanced chemical equation as: [1] 
 (a) NaOH + Zn ? NaZnO2 + H2O (b) 2NaOH + Zn ? Na2ZnO2 + H2 
 (c) 2NaOH + Zn ? NaZnO2 + H2 (d) 2NaOH + Zn ? Na2ZnO2 + H2O 
Answer (b)   [1] 
Sol. When zinc reacts with sodium hydroxide solution, sodium zincate and hydrogen gas are produced. 
 
22 2
2NaOH Zn Na ZnO H ????? 
3. MnO2 + 4HCl ? MnCl2 + 2H2O + Cl2 [1] 
 The reaction given above is a redox reaction because in this case : 
 (a) MnO2 is oxidised and HCl is reduced (b) HCl is oxidised 
 (c) MnO2 is reduced (d) MnO2 is reduced and HCI is oxidised 
Answer (d)   [1] 
Sol.  
4. Consider the following compounds : 
 FeSO4; CuSO4; CaSO4; Na2CO3 
 The compound having maximum number of water of crystallisation in its crystalline form in one molecule is : [1] 
 (a) FeSO4 (b) CuSO4 
 (c) CaSO4 (d) Na2CO3 
Answer (d)   [1] 
Sol. 
442
(Green vitriol)
442
(Blue vitriol)
442
(Gypsum)
23 23 2
(Washing soda)
FeSO FeSO 7H O
CuSO CuSO 5H O
CaSO CaSO 2H O
Na CO Na CO 10H O
?
?
?
?
Compound Crystalline form 
5. In a nerve cell, the site where the electrical impulse is converted into a chemical signal is known as: [1] 
 (a) Axon (b) Dendrites 
 (c) Neuromuscular junction (d) Cell body 
Answer (c)   [1] 
Sol. Neuromuscular junction is the site where the electrical impulse is converted into a chemical signal for onward 
transmission. 
6. A metal and a non-metal that exists in liquid state at the room temperature are respectively: [1] 
 (a) Bromine and Mercury (b) Mercury and Iodine 
 (c) Mercury and Bromine (d) Iodine and Mercury 
Answer (c)   [1] 
Sol. Mercury is a metal which exists in liquid state at the room temperature whereas bromine is a non-metal which 
exists in liquid state at the room temperature. 
7. At what distance from a convex lens should an object be placed to get an image of the same size as that of the 
object on a screen? [1] 
 (a) Beyond twice the focal length of the lens 
 (b) At the principal focus of the lens 
 (c) At twice the focal length of the lens 
 (d) Between the optical centre of the lens and its principal focus 
Answer (c)    [1] 
Sol. When object is placed at twice the focal length of a convex lens, an image of the same size as that of the 
object is formed. 
8. Carbon compounds : [1] 
 (i) are good conductors of electricity. 
 (ii) are bad conductors of electricity. 
 (iii) have strong forces of attraction between their molecules. 
 (iv) have weak forces of attraction between their molecules. 
 The correct statements are: 
 (a) (i) and (ii) (b) (ii) and (iii) 
 (c) (ii) and (iv) (d) (i) and (iii) 
Answer (c)   [1] 
Sol. Carbon compounds are bad conductors of electricity as they contain covalent bonds. Force of attraction 
between their molecules are not very strong. 
  
9. Oxides of aluminium and zinc are: [1] 
 (a) acidic (b) basic 
 (c) amphoteric (d) neutral 
Answer (c)   [1] 
Sol. Al
2
O
3
 and ZnO are amphoteric in nature because they react with both acids and bases. 
10. Chromosomes : [1] 
 (i) carry hereditary information from parents to the next generation. 
 (ii) are thread like structures located inside the nucleus of an animal cell. 
 (iii) always exist in pairs in human reproductive cells. 
 (iv) are involved in the process of cell division. 
 The correct statements are : 
 (a) (i) and (ii) (b) (iii) and (iv) 
 (c) (i), (ii) and (iv) (d) (i) and (iv) 
Answer (c)   [1] 
Sol. Chromosomes are thread-like structures which carry hereditary information  and are involved in the process 
of cell division. 
11. Consider the following statements : [1] 
 (i) The sex of a child is determined by what it inherits from the mother. 
 (ii) The sex of a child is determined by what it inherits from the father. 
 (iii) The probability of having a male child is more than that of a female child. 
 (iv) The sex of a child is determined at the time of fertilisation when male and female gametes fuse to form a 
zygote. 
 The correct statements are : 
 (a) (i) and (iii) (b) (ii) and (iv) 
 (c) (iii) and (iv) (d) (i), (iii) and (iv) 
Answer (b)   [1] 
Sol. A child who inherits an X chromosome from her father will be a girl and one who inherits a Y chromosome 
from him will be a boy. 
12. Which one of the following organ is NOT a part of human female reproductive system? [1] 
 (a) Ovary (b) Uterus 
 (c) Vas deferens (d) Fallopian tube 
Answer (c)   [1] 
Sol. Vas deferens is a part of the male reproductive system. 
13. In which of the following organisms, multiple fission is a means of asexual reproduction? [1] 
 (a) Yeast (b) Leishmania 
 (c) Paramoecium (d) Plasmodium 
Answer (d)   [1] 
Sol. Plasmodium, divides into many daughter cells simultaneously by multiple fission. 
Page 5


- 1 - 
 
 
SCIENCE 
CBSE Class-X (2024) 
Answers & Solutions
GENERAL INSTRUCTIONS 
Read the following instructions very carefully and strictly follow them : 
(i) This question paper comprises 39 questions. All questions are compulsory. 
(ii) The question paper is divided into FIVE sections – A, B, C, D and E.  
(iii) Section-A - Question Nos. 1 to 20 are multiple choice questions (MCQs). Each question carries 1 mark. 
(iv) Section-B - Question Nos. 21 to 26 are very short answer (VSA) type questions. Each question carries 2 marks. 
Answer to these questions should be in the range of 30 to 50 words. 
(v) Section-C - Question Nos. 27 to 33 are short answer (SA) type questions. Each question carries 3 marks. Answer to 
these questions should be in the range of 50 to 80 words. 
(vi) Section-D - Question Nos. 34 to 36 are long answer (LA) type questions. Each question carries 5 marks. Answer to 
these questions should be in the range of 80 to 120 words. 
(vii) Section-E - Question Nos. 37 to 39 are of 3 source-based/case-based units of assessment carrying 4 marks each 
with sub-parts. 
(viii) There is no overall choice. However, an internal choice has been provided in some sections. Only one of the 
alternatives has to be attempted in such questions. 
  
Date: 02/03/2024 
Time: 3 Hours Max. Marks: 80 
Question Paper Code 
31/1/3 
  
SECTION-A 
Multiple Choice Type Questions : [16×1=16] 
Select and write the most appropriate option out of the four options given for each of the questions 1-20. 
There is no negative mark for the incorrect response. 
1. Select from the following a decomposition reaction in which source of energy for decomposition is light: [1] 
 (a) 2FeSO4 ? Fe2O3 + SO2 + SO3 (b) 2H2O ? 2H2 + O2 
 (c) 2AgBr ??2Ag + Br2 (d) CaCO3 ? CaO + CO2 
Answer (c)   [1] 
Sol. 
Heat
42323
2FeSO Fe O SO SO ?? ? ? ? ? 
 
Electric current
222
2H O 2H O ????? ???? 
 
Sunlight
2
2AgBr 2Ag Br ?? ? ? ??? 
 
Heat
32
CaCO CaO CO ?? ? ? ? 
2. When 2 mL of sodium hydroxide solution is added to few pieces of granulated zinc in a test tube and then 
warmed, the reaction that occurs can be written in the form of a balanced chemical equation as: [1] 
 (a) NaOH + Zn ? NaZnO2 + H2O (b) 2NaOH + Zn ? Na2ZnO2 + H2 
 (c) 2NaOH + Zn ? NaZnO2 + H2 (d) 2NaOH + Zn ? Na2ZnO2 + H2O 
Answer (b)   [1] 
Sol. When zinc reacts with sodium hydroxide solution, sodium zincate and hydrogen gas are produced. 
 
22 2
2NaOH Zn Na ZnO H ????? 
3. MnO2 + 4HCl ? MnCl2 + 2H2O + Cl2 [1] 
 The reaction given above is a redox reaction because in this case : 
 (a) MnO2 is oxidised and HCl is reduced (b) HCl is oxidised 
 (c) MnO2 is reduced (d) MnO2 is reduced and HCI is oxidised 
Answer (d)   [1] 
Sol.  
4. Consider the following compounds : 
 FeSO4; CuSO4; CaSO4; Na2CO3 
 The compound having maximum number of water of crystallisation in its crystalline form in one molecule is : [1] 
 (a) FeSO4 (b) CuSO4 
 (c) CaSO4 (d) Na2CO3 
Answer (d)   [1] 
Sol. 
442
(Green vitriol)
442
(Blue vitriol)
442
(Gypsum)
23 23 2
(Washing soda)
FeSO FeSO 7H O
CuSO CuSO 5H O
CaSO CaSO 2H O
Na CO Na CO 10H O
?
?
?
?
Compound Crystalline form 
5. In a nerve cell, the site where the electrical impulse is converted into a chemical signal is known as: [1] 
 (a) Axon (b) Dendrites 
 (c) Neuromuscular junction (d) Cell body 
Answer (c)   [1] 
Sol. Neuromuscular junction is the site where the electrical impulse is converted into a chemical signal for onward 
transmission. 
6. A metal and a non-metal that exists in liquid state at the room temperature are respectively: [1] 
 (a) Bromine and Mercury (b) Mercury and Iodine 
 (c) Mercury and Bromine (d) Iodine and Mercury 
Answer (c)   [1] 
Sol. Mercury is a metal which exists in liquid state at the room temperature whereas bromine is a non-metal which 
exists in liquid state at the room temperature. 
7. At what distance from a convex lens should an object be placed to get an image of the same size as that of the 
object on a screen? [1] 
 (a) Beyond twice the focal length of the lens 
 (b) At the principal focus of the lens 
 (c) At twice the focal length of the lens 
 (d) Between the optical centre of the lens and its principal focus 
Answer (c)    [1] 
Sol. When object is placed at twice the focal length of a convex lens, an image of the same size as that of the 
object is formed. 
8. Carbon compounds : [1] 
 (i) are good conductors of electricity. 
 (ii) are bad conductors of electricity. 
 (iii) have strong forces of attraction between their molecules. 
 (iv) have weak forces of attraction between their molecules. 
 The correct statements are: 
 (a) (i) and (ii) (b) (ii) and (iii) 
 (c) (ii) and (iv) (d) (i) and (iii) 
Answer (c)   [1] 
Sol. Carbon compounds are bad conductors of electricity as they contain covalent bonds. Force of attraction 
between their molecules are not very strong. 
  
9. Oxides of aluminium and zinc are: [1] 
 (a) acidic (b) basic 
 (c) amphoteric (d) neutral 
Answer (c)   [1] 
Sol. Al
2
O
3
 and ZnO are amphoteric in nature because they react with both acids and bases. 
10. Chromosomes : [1] 
 (i) carry hereditary information from parents to the next generation. 
 (ii) are thread like structures located inside the nucleus of an animal cell. 
 (iii) always exist in pairs in human reproductive cells. 
 (iv) are involved in the process of cell division. 
 The correct statements are : 
 (a) (i) and (ii) (b) (iii) and (iv) 
 (c) (i), (ii) and (iv) (d) (i) and (iv) 
Answer (c)   [1] 
Sol. Chromosomes are thread-like structures which carry hereditary information  and are involved in the process 
of cell division. 
11. Consider the following statements : [1] 
 (i) The sex of a child is determined by what it inherits from the mother. 
 (ii) The sex of a child is determined by what it inherits from the father. 
 (iii) The probability of having a male child is more than that of a female child. 
 (iv) The sex of a child is determined at the time of fertilisation when male and female gametes fuse to form a 
zygote. 
 The correct statements are : 
 (a) (i) and (iii) (b) (ii) and (iv) 
 (c) (iii) and (iv) (d) (i), (iii) and (iv) 
Answer (b)   [1] 
Sol. A child who inherits an X chromosome from her father will be a girl and one who inherits a Y chromosome 
from him will be a boy. 
12. Which one of the following organ is NOT a part of human female reproductive system? [1] 
 (a) Ovary (b) Uterus 
 (c) Vas deferens (d) Fallopian tube 
Answer (c)   [1] 
Sol. Vas deferens is a part of the male reproductive system. 
13. In which of the following organisms, multiple fission is a means of asexual reproduction? [1] 
 (a) Yeast (b) Leishmania 
 (c) Paramoecium (d) Plasmodium 
Answer (d)   [1] 
Sol. Plasmodium, divides into many daughter cells simultaneously by multiple fission. 
14. In bifocal lenses used for the correction of presbyopia: [1] 
 (a) the upper portion is of convex lens for the near vision and lower part is of concave lens for the distant 
vision. 
 (b) the upper portion is of convex lens for the distant vision and lower part is of concave lens for the near 
vision. 
 (c) the upper portion is of concave lens is for the near vision and lower part is of convex lens for the distant 
vision. 
 (d) the upper portion is of concave lens for the distant vision and lower part is of convex lens for the near 
vision. 
Answer (d)   [1] 
Sol. The upper portion of the bifocal lens is a concave lens so as to focus the distant objects and the lower portion 
of the bifocal lens is a convex lens so as to focus the nearby objects 
15. The pattern of the magnetic field produced inside a current carrying solenoid is : [1] 
 (a)  (b)  
 (c)  (d)  
Answer (a)   [1] 
Sol. The magnetic field is nearly uniform inside the solenoid hence, the field lines are parallel straight lines inside 
the solenoid. 
16. Identify the food chain in which the organisms of the second trophic level are missing:  [1] 
 (a) Grass, goat, lion (b) Zooplankton, Phytoplankton, small fish, large fish 
 (c) Tiger, grass, snake, frog (d) Grasshopper, grass, snake, frog, eagle 
Answer (c)    [1] 
Sol. The herbivores or the primary consumers occupy the second trophic level which is missing in the food chain 
i.e., tiger, grass, snake, frog. 
Assertion & Reason Type Questions : [4×1=4] 
For Q. Nos. 17 to 20, two statements are given – One labelled as Assertion (A) and the other labelled as 
Reason (R). Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below : 
 (a) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A). 
 (b) Both Assertion (A) and Reason (R) are true but Reason (R) is not the correct explanation of Assertion (A). 
 (c) Assertion (A) is true, but Reason (R) is false. 
 (d) Assertion (A) is false, but Reason (R) is true. 
17. Assertion (A) : The rainbow is a natural spectrum of sunlight in the sky. [1] 
 Reason (R) : Rainbow is formed in the sky when the sun is overhead and water droplets are also present in 
air. 
Answer (c)    [1] 
Sol. A rainbow is always formed in a direction opposite to that of the sun.