Class 12 Biology: CBSE Sample Question Paper (2023-24) | Sample Papers for Class 12 Medical and Non-Medical PDF Download

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1 
 
Sample Question Paper 2023-24 
Class XII  
Biology (Subject Code-044) 
Maximum Marks: 70                                                                                           Time: 3 hours  
 
General Instructions: 
(i) All questions are compulsory.  
(ii) The question paper has five sections and 33 questions. All questions are compulsory. 
(iii) Section–A has 16 questions of 1 mark each; Section–B has 5 questions of 2 marks each; Section– C 
has 7 questions of 3 marks each; Section– D has 2 case-based questions of 4 marks each; and 
Section–E has 3 questions of 5 marks each. 
(iv) There is no overall choice. However, internal choices have been provided in some questions. A 
student has to attempt only one of the alternatives in such questions. 
(v) Wherever necessary, neat and properly labeled diagrams should be drawn. 
Section - A 
Q.No. Question Marks 
1 Remnants of nucellus are persistent during seed development in: 
a) pea 
b) groundnut 
c) wheat 
d) black pepper 
1 
2 The wall layer of microsporangium which nourishes the pollen grain is: 
a) epidermis 
b) endothecium 
c) middle layers 
d) tapetum 
1 
3 A short piece of DNA, having 20 base pairs, was analyzed to find the number of  
nucleotide bases in each of the polynucleotide strands. Some of the results are 
shown in the table.  
 Number of nucleotide bases 
 Adenine Cytosine Guanine Thymine 
Strand 1 4 4   
Strand 2  5   
How many nucleotides containing Adenine were present in strand 2? 
a) 2  
b) 4  
c) 5 
d) 7  
1 
Page 2


1 
 
Sample Question Paper 2023-24 
Class XII  
Biology (Subject Code-044) 
Maximum Marks: 70                                                                                           Time: 3 hours  
 
General Instructions: 
(i) All questions are compulsory.  
(ii) The question paper has five sections and 33 questions. All questions are compulsory. 
(iii) Section–A has 16 questions of 1 mark each; Section–B has 5 questions of 2 marks each; Section– C 
has 7 questions of 3 marks each; Section– D has 2 case-based questions of 4 marks each; and 
Section–E has 3 questions of 5 marks each. 
(iv) There is no overall choice. However, internal choices have been provided in some questions. A 
student has to attempt only one of the alternatives in such questions. 
(v) Wherever necessary, neat and properly labeled diagrams should be drawn. 
Section - A 
Q.No. Question Marks 
1 Remnants of nucellus are persistent during seed development in: 
a) pea 
b) groundnut 
c) wheat 
d) black pepper 
1 
2 The wall layer of microsporangium which nourishes the pollen grain is: 
a) epidermis 
b) endothecium 
c) middle layers 
d) tapetum 
1 
3 A short piece of DNA, having 20 base pairs, was analyzed to find the number of  
nucleotide bases in each of the polynucleotide strands. Some of the results are 
shown in the table.  
 Number of nucleotide bases 
 Adenine Cytosine Guanine Thymine 
Strand 1 4 4   
Strand 2  5   
How many nucleotides containing Adenine were present in strand 2? 
a) 2  
b) 4  
c) 5 
d) 7  
1 
2 
 
4 
In a certain species of insects, some have 13 chromosomes, and the others have 
14chromosomes.The 13 and 14 chromosome bearing organisms are 
a) males and females, respectively 
b) females and males, respectively 
c) all males 
d) all females 
1 
5 
At a particular locus, the frequency of allele A is 0.8 and that of allele a is 0.2. 
What would be the frequency of heterozygotes in a random mating population at 
equilibrium? 
a) 0.32 
b) 0.16 
c) 0.24 
d) 0.48 
1 
6 
Variations caused due to  mutations are 
a) random and directionless 
b) random and directional 
c) random and small 
d) random, small and directional 
1 
7 
What is the smallest part of a DNA molecule that can be changed by a point 
mutation? 
a) Oligonucleotide 
b) Codon 
c) Gene 
d) Nucleotide 
1 
8 What should be the genotype of the indicated member? 
 
a) AA 
b) Aa 
c) XY 
d) aa 
1 
Page 3


1 
 
Sample Question Paper 2023-24 
Class XII  
Biology (Subject Code-044) 
Maximum Marks: 70                                                                                           Time: 3 hours  
 
General Instructions: 
(i) All questions are compulsory.  
(ii) The question paper has five sections and 33 questions. All questions are compulsory. 
(iii) Section–A has 16 questions of 1 mark each; Section–B has 5 questions of 2 marks each; Section– C 
has 7 questions of 3 marks each; Section– D has 2 case-based questions of 4 marks each; and 
Section–E has 3 questions of 5 marks each. 
(iv) There is no overall choice. However, internal choices have been provided in some questions. A 
student has to attempt only one of the alternatives in such questions. 
(v) Wherever necessary, neat and properly labeled diagrams should be drawn. 
Section - A 
Q.No. Question Marks 
1 Remnants of nucellus are persistent during seed development in: 
a) pea 
b) groundnut 
c) wheat 
d) black pepper 
1 
2 The wall layer of microsporangium which nourishes the pollen grain is: 
a) epidermis 
b) endothecium 
c) middle layers 
d) tapetum 
1 
3 A short piece of DNA, having 20 base pairs, was analyzed to find the number of  
nucleotide bases in each of the polynucleotide strands. Some of the results are 
shown in the table.  
 Number of nucleotide bases 
 Adenine Cytosine Guanine Thymine 
Strand 1 4 4   
Strand 2  5   
How many nucleotides containing Adenine were present in strand 2? 
a) 2  
b) 4  
c) 5 
d) 7  
1 
2 
 
4 
In a certain species of insects, some have 13 chromosomes, and the others have 
14chromosomes.The 13 and 14 chromosome bearing organisms are 
a) males and females, respectively 
b) females and males, respectively 
c) all males 
d) all females 
1 
5 
At a particular locus, the frequency of allele A is 0.8 and that of allele a is 0.2. 
What would be the frequency of heterozygotes in a random mating population at 
equilibrium? 
a) 0.32 
b) 0.16 
c) 0.24 
d) 0.48 
1 
6 
Variations caused due to  mutations are 
a) random and directionless 
b) random and directional 
c) random and small 
d) random, small and directional 
1 
7 
What is the smallest part of a DNA molecule that can be changed by a point 
mutation? 
a) Oligonucleotide 
b) Codon 
c) Gene 
d) Nucleotide 
1 
8 What should be the genotype of the indicated member? 
 
a) AA 
b) Aa 
c) XY 
d) aa 
1 
3 
 
9 
A patient was advised to have a kidney transplant. To suppress the immune 
reaction, the doctor would administer him: 
a) statins produced from Monascus purpureus 
b) statins produced from Streptococcus thermophilus 
c) cyclosporin A produced from Trichoderma polysporum 
d) cyclosporin A produced from Clostridium butylicum 
1 
10 Identify the activity of endonuclease and exonuclease in the given image. 
 
1 
11 
The main objective of production of pest resistant GM crops is to 
a) encourage eco-friendly pesticides 
b) reduce pesticide accumulation in food chain 
c) eliminate pests from the field without the use of manual labour 
d) retain maximum nutritional content in the crop that would be otherwise 
consumed by pest 
1 
12 Observe the contents 1,2,3 and 4 of soil samples A,B and C shown in the graph. If 
the temperature and soil moisture of all soil samples are identical, which soil 
sample (s) will show faster decomposition? 
 
1 
Page 4


1 
 
Sample Question Paper 2023-24 
Class XII  
Biology (Subject Code-044) 
Maximum Marks: 70                                                                                           Time: 3 hours  
 
General Instructions: 
(i) All questions are compulsory.  
(ii) The question paper has five sections and 33 questions. All questions are compulsory. 
(iii) Section–A has 16 questions of 1 mark each; Section–B has 5 questions of 2 marks each; Section– C 
has 7 questions of 3 marks each; Section– D has 2 case-based questions of 4 marks each; and 
Section–E has 3 questions of 5 marks each. 
(iv) There is no overall choice. However, internal choices have been provided in some questions. A 
student has to attempt only one of the alternatives in such questions. 
(v) Wherever necessary, neat and properly labeled diagrams should be drawn. 
Section - A 
Q.No. Question Marks 
1 Remnants of nucellus are persistent during seed development in: 
a) pea 
b) groundnut 
c) wheat 
d) black pepper 
1 
2 The wall layer of microsporangium which nourishes the pollen grain is: 
a) epidermis 
b) endothecium 
c) middle layers 
d) tapetum 
1 
3 A short piece of DNA, having 20 base pairs, was analyzed to find the number of  
nucleotide bases in each of the polynucleotide strands. Some of the results are 
shown in the table.  
 Number of nucleotide bases 
 Adenine Cytosine Guanine Thymine 
Strand 1 4 4   
Strand 2  5   
How many nucleotides containing Adenine were present in strand 2? 
a) 2  
b) 4  
c) 5 
d) 7  
1 
2 
 
4 
In a certain species of insects, some have 13 chromosomes, and the others have 
14chromosomes.The 13 and 14 chromosome bearing organisms are 
a) males and females, respectively 
b) females and males, respectively 
c) all males 
d) all females 
1 
5 
At a particular locus, the frequency of allele A is 0.8 and that of allele a is 0.2. 
What would be the frequency of heterozygotes in a random mating population at 
equilibrium? 
a) 0.32 
b) 0.16 
c) 0.24 
d) 0.48 
1 
6 
Variations caused due to  mutations are 
a) random and directionless 
b) random and directional 
c) random and small 
d) random, small and directional 
1 
7 
What is the smallest part of a DNA molecule that can be changed by a point 
mutation? 
a) Oligonucleotide 
b) Codon 
c) Gene 
d) Nucleotide 
1 
8 What should be the genotype of the indicated member? 
 
a) AA 
b) Aa 
c) XY 
d) aa 
1 
3 
 
9 
A patient was advised to have a kidney transplant. To suppress the immune 
reaction, the doctor would administer him: 
a) statins produced from Monascus purpureus 
b) statins produced from Streptococcus thermophilus 
c) cyclosporin A produced from Trichoderma polysporum 
d) cyclosporin A produced from Clostridium butylicum 
1 
10 Identify the activity of endonuclease and exonuclease in the given image. 
 
1 
11 
The main objective of production of pest resistant GM crops is to 
a) encourage eco-friendly pesticides 
b) reduce pesticide accumulation in food chain 
c) eliminate pests from the field without the use of manual labour 
d) retain maximum nutritional content in the crop that would be otherwise 
consumed by pest 
1 
12 Observe the contents 1,2,3 and 4 of soil samples A,B and C shown in the graph. If 
the temperature and soil moisture of all soil samples are identical, which soil 
sample (s) will show faster decomposition? 
 
1 
4 
 
a) Soil Sample A 
b) Soil Sample B 
c) Soil Samples A and B both 
d) Soil Sample C 
Question No. 13 to 16 consist of two statements – Assertion (A) and Reason (R). Answer these 
questions selecting the appropriate option given below:  
a) Both A and R are true and R is the correct explanation of A.  
b) Both A and R are true and R is not the correct explanation of A.  
c) A is true but R is false.  
d) A is false but R is true. 
13 
Assertion: Primary endosperm nucleus is diploid. 
Reason: It is the product of double fertilisation. 
1 
14 
Assertion:Ribosomal RNA is synthesized in the nucleus of the cell. 
Reason: It is translated with the enzyme RNA polymerase III. 
1 
15 
Assertion: Smoking can raise blood pressure and increase heart rate. 
Reason: Nicotine stimulates adrenal glands to release adrenaline and nor-
adrenaline into the blood circulation, both of which raise blood pressure and 
increase heart rate.         
1 
16 
Assertion: PCR is a powerful technique to identify genetic disorders. 
Reason: PCR can detect mutations in low amounts of DNA.  
1 
Section - B 
17 Explain the process of hormonal regulation of spermatogenesis. 2 
18 
The diagram below shows the sequence of amino acids in part of a haemoglobin 
molecule.  
 
2 
Page 5


1 
 
Sample Question Paper 2023-24 
Class XII  
Biology (Subject Code-044) 
Maximum Marks: 70                                                                                           Time: 3 hours  
 
General Instructions: 
(i) All questions are compulsory.  
(ii) The question paper has five sections and 33 questions. All questions are compulsory. 
(iii) Section–A has 16 questions of 1 mark each; Section–B has 5 questions of 2 marks each; Section– C 
has 7 questions of 3 marks each; Section– D has 2 case-based questions of 4 marks each; and 
Section–E has 3 questions of 5 marks each. 
(iv) There is no overall choice. However, internal choices have been provided in some questions. A 
student has to attempt only one of the alternatives in such questions. 
(v) Wherever necessary, neat and properly labeled diagrams should be drawn. 
Section - A 
Q.No. Question Marks 
1 Remnants of nucellus are persistent during seed development in: 
a) pea 
b) groundnut 
c) wheat 
d) black pepper 
1 
2 The wall layer of microsporangium which nourishes the pollen grain is: 
a) epidermis 
b) endothecium 
c) middle layers 
d) tapetum 
1 
3 A short piece of DNA, having 20 base pairs, was analyzed to find the number of  
nucleotide bases in each of the polynucleotide strands. Some of the results are 
shown in the table.  
 Number of nucleotide bases 
 Adenine Cytosine Guanine Thymine 
Strand 1 4 4   
Strand 2  5   
How many nucleotides containing Adenine were present in strand 2? 
a) 2  
b) 4  
c) 5 
d) 7  
1 
2 
 
4 
In a certain species of insects, some have 13 chromosomes, and the others have 
14chromosomes.The 13 and 14 chromosome bearing organisms are 
a) males and females, respectively 
b) females and males, respectively 
c) all males 
d) all females 
1 
5 
At a particular locus, the frequency of allele A is 0.8 and that of allele a is 0.2. 
What would be the frequency of heterozygotes in a random mating population at 
equilibrium? 
a) 0.32 
b) 0.16 
c) 0.24 
d) 0.48 
1 
6 
Variations caused due to  mutations are 
a) random and directionless 
b) random and directional 
c) random and small 
d) random, small and directional 
1 
7 
What is the smallest part of a DNA molecule that can be changed by a point 
mutation? 
a) Oligonucleotide 
b) Codon 
c) Gene 
d) Nucleotide 
1 
8 What should be the genotype of the indicated member? 
 
a) AA 
b) Aa 
c) XY 
d) aa 
1 
3 
 
9 
A patient was advised to have a kidney transplant. To suppress the immune 
reaction, the doctor would administer him: 
a) statins produced from Monascus purpureus 
b) statins produced from Streptococcus thermophilus 
c) cyclosporin A produced from Trichoderma polysporum 
d) cyclosporin A produced from Clostridium butylicum 
1 
10 Identify the activity of endonuclease and exonuclease in the given image. 
 
1 
11 
The main objective of production of pest resistant GM crops is to 
a) encourage eco-friendly pesticides 
b) reduce pesticide accumulation in food chain 
c) eliminate pests from the field without the use of manual labour 
d) retain maximum nutritional content in the crop that would be otherwise 
consumed by pest 
1 
12 Observe the contents 1,2,3 and 4 of soil samples A,B and C shown in the graph. If 
the temperature and soil moisture of all soil samples are identical, which soil 
sample (s) will show faster decomposition? 
 
1 
4 
 
a) Soil Sample A 
b) Soil Sample B 
c) Soil Samples A and B both 
d) Soil Sample C 
Question No. 13 to 16 consist of two statements – Assertion (A) and Reason (R). Answer these 
questions selecting the appropriate option given below:  
a) Both A and R are true and R is the correct explanation of A.  
b) Both A and R are true and R is not the correct explanation of A.  
c) A is true but R is false.  
d) A is false but R is true. 
13 
Assertion: Primary endosperm nucleus is diploid. 
Reason: It is the product of double fertilisation. 
1 
14 
Assertion:Ribosomal RNA is synthesized in the nucleus of the cell. 
Reason: It is translated with the enzyme RNA polymerase III. 
1 
15 
Assertion: Smoking can raise blood pressure and increase heart rate. 
Reason: Nicotine stimulates adrenal glands to release adrenaline and nor-
adrenaline into the blood circulation, both of which raise blood pressure and 
increase heart rate.         
1 
16 
Assertion: PCR is a powerful technique to identify genetic disorders. 
Reason: PCR can detect mutations in low amounts of DNA.  
1 
Section - B 
17 Explain the process of hormonal regulation of spermatogenesis. 2 
18 
The diagram below shows the sequence of amino acids in part of a haemoglobin 
molecule.  
 
2 
5 
 
a) If the base T* was substituted with A, how would it affect the haemoglobin 
chain?   
b) Name the condition and the effects associated with the above substitution. 
19 The graph given below indicates the administration of the first (L) and second dose 
(M) of a vaccine. The corresponding response of the body is indicated by X and Y. 
Interpret the graph and explain the reason for such a response shown by the 
body. 
 
2 
20 The image below shows the result of plating bacteria in chromogenic medium after 
incorporating the gene of interest in plasmid. Some plates had blue colonies; some 
plates had white colonies. A single bacterium extracted from Plate I,II,III is shown 
below: 
 
On the basis of your observations  
a)    Identify the plate(s) which is/are white. Give a reason. 
b)    Identify the plate(s) which is/are blue. Give a reason. 
2