CBSE Biology Past year paper Delhi (Set - 3) - 2013, Class 12 | Additional Study Material for NEET PDF Download

 Page 1


  
 
CBSE XII  |  Biology 
Board Paper 2013 – Delhi – Set 3 
 
     
CBSE 
 Class XII Biology 
Board Paper 2013 - Delhi (Set 3) 
 
Time: 3 hrs Total Marks: 70 
 
General Instruction: 
1. All questions are compulsory. 
2. This question paper consists of four Sections A, B C and D. Section A contains 8  
questions of one mark each, Section B is of 10 questions of two marks each, Section C is 
of 9 questions of three marks each, and Section D is of 3 questions of five marks each.  
3. There is no overall choice. However an internal choice has been provided in one  
question of 2 marks, one question of 3 marks and all the three questions of 5 marks 
weight age. A student has to attempt only one of the alternatives in such questions. 
4. Wherever necessary, the diagrams drawn should be neat and properly labelled. 
 
SECTION A 
 
1. Why is the enzyme cellulase needed for isolating genetic material from plant cells 
and not form the animal cells? [1] 
 
2. Write the importance of MOET.  [1] 
 
 
3. An anther with malfunctioning tapetum often fails to produce viable male 
gametophytes. Give any one reason.  [1] 
 
 
4. Why sharing of injection needles between two individuals are not recommended? [1] 
 
 
5. Name the enzyme and state its property that is responsible for continuous and 
discontinuous replication of the two strands of a DNA molecule. [1] 
 
 
6. “Sweet potato tubers and potato tubers are the result of convergent evolution.” 
Justify the statement.  [1] 
 
7. Write the equation that helps in deriving the net primary productivity of an 
ecosystem.  [1] 
 
8. Name the type biodiversity represented by the following:  [1] 
(a) 50,000 different strains of rice in India. 
(b) Estuaries and alpine meadows in India 
 
 
 
 
 
Page 2


  
 
CBSE XII  |  Biology 
Board Paper 2013 – Delhi – Set 3 
 
     
CBSE 
 Class XII Biology 
Board Paper 2013 - Delhi (Set 3) 
 
Time: 3 hrs Total Marks: 70 
 
General Instruction: 
1. All questions are compulsory. 
2. This question paper consists of four Sections A, B C and D. Section A contains 8  
questions of one mark each, Section B is of 10 questions of two marks each, Section C is 
of 9 questions of three marks each, and Section D is of 3 questions of five marks each.  
3. There is no overall choice. However an internal choice has been provided in one  
question of 2 marks, one question of 3 marks and all the three questions of 5 marks 
weight age. A student has to attempt only one of the alternatives in such questions. 
4. Wherever necessary, the diagrams drawn should be neat and properly labelled. 
 
SECTION A 
 
1. Why is the enzyme cellulase needed for isolating genetic material from plant cells 
and not form the animal cells? [1] 
 
2. Write the importance of MOET.  [1] 
 
 
3. An anther with malfunctioning tapetum often fails to produce viable male 
gametophytes. Give any one reason.  [1] 
 
 
4. Why sharing of injection needles between two individuals are not recommended? [1] 
 
 
5. Name the enzyme and state its property that is responsible for continuous and 
discontinuous replication of the two strands of a DNA molecule. [1] 
 
 
6. “Sweet potato tubers and potato tubers are the result of convergent evolution.” 
Justify the statement.  [1] 
 
7. Write the equation that helps in deriving the net primary productivity of an 
ecosystem.  [1] 
 
8. Name the type biodiversity represented by the following:  [1] 
(a) 50,000 different strains of rice in India. 
(b) Estuaries and alpine meadows in India 
 
 
 
 
 
  
 
CBSE XII  |  Biology 
Board Paper 2013 – Delhi – Set 3 
 
     
 
SECTION B 
 
9. Explain why very small animals are rarely found in polar region.  [2] 
 
10. Why the pyramid of energy is always upright? Explain.  [2] 
 
11. Expand the following and mention one application of each: 
1) PCR 
2) ELISA 
OR 
 
(a) Mention the difference in the mode of action of exonuclease and endonuclease. 
(b) How does restriction endonuclease function?  [2] 
 
12. Name any two sources of e-Wastes and write two difference ways of their disposal. [2] 
 
13.  Explain the steps that ensure cross pollination in an autogamous flower.  [2] 
 
14.  When and where do chorionic villi appear in humans? State their function.  [2] 
 
15.  In a cross between two tall pea plants some of the offsprings produced were dwarf. 
Show with the help of Punett square how this is possible.  [2] 
16.  A student on a school picnic to park on a windy day started sneezing and having 
difficulty in breathing in reaching the park. The teacher enquired whether the 
student was allergic to something. 
(a) What is an allergy? 
(b) Write the two unique characteristics of the system involved in the response 
observed in the student.  [2] 
 
17.  Why and how bacteria can be made ‘competent’?  [2] 
 
18.  
(a) Name the deficiency for which first clinical gene therapy was given. 
(b) Mention the cause of and one cure for this deficiency.  [2] 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Page 3


  
 
CBSE XII  |  Biology 
Board Paper 2013 – Delhi – Set 3 
 
     
CBSE 
 Class XII Biology 
Board Paper 2013 - Delhi (Set 3) 
 
Time: 3 hrs Total Marks: 70 
 
General Instruction: 
1. All questions are compulsory. 
2. This question paper consists of four Sections A, B C and D. Section A contains 8  
questions of one mark each, Section B is of 10 questions of two marks each, Section C is 
of 9 questions of three marks each, and Section D is of 3 questions of five marks each.  
3. There is no overall choice. However an internal choice has been provided in one  
question of 2 marks, one question of 3 marks and all the three questions of 5 marks 
weight age. A student has to attempt only one of the alternatives in such questions. 
4. Wherever necessary, the diagrams drawn should be neat and properly labelled. 
 
SECTION A 
 
1. Why is the enzyme cellulase needed for isolating genetic material from plant cells 
and not form the animal cells? [1] 
 
2. Write the importance of MOET.  [1] 
 
 
3. An anther with malfunctioning tapetum often fails to produce viable male 
gametophytes. Give any one reason.  [1] 
 
 
4. Why sharing of injection needles between two individuals are not recommended? [1] 
 
 
5. Name the enzyme and state its property that is responsible for continuous and 
discontinuous replication of the two strands of a DNA molecule. [1] 
 
 
6. “Sweet potato tubers and potato tubers are the result of convergent evolution.” 
Justify the statement.  [1] 
 
7. Write the equation that helps in deriving the net primary productivity of an 
ecosystem.  [1] 
 
8. Name the type biodiversity represented by the following:  [1] 
(a) 50,000 different strains of rice in India. 
(b) Estuaries and alpine meadows in India 
 
 
 
 
 
  
 
CBSE XII  |  Biology 
Board Paper 2013 – Delhi – Set 3 
 
     
 
SECTION B 
 
9. Explain why very small animals are rarely found in polar region.  [2] 
 
10. Why the pyramid of energy is always upright? Explain.  [2] 
 
11. Expand the following and mention one application of each: 
1) PCR 
2) ELISA 
OR 
 
(a) Mention the difference in the mode of action of exonuclease and endonuclease. 
(b) How does restriction endonuclease function?  [2] 
 
12. Name any two sources of e-Wastes and write two difference ways of their disposal. [2] 
 
13.  Explain the steps that ensure cross pollination in an autogamous flower.  [2] 
 
14.  When and where do chorionic villi appear in humans? State their function.  [2] 
 
15.  In a cross between two tall pea plants some of the offsprings produced were dwarf. 
Show with the help of Punett square how this is possible.  [2] 
16.  A student on a school picnic to park on a windy day started sneezing and having 
difficulty in breathing in reaching the park. The teacher enquired whether the 
student was allergic to something. 
(a) What is an allergy? 
(b) Write the two unique characteristics of the system involved in the response 
observed in the student.  [2] 
 
17.  Why and how bacteria can be made ‘competent’?  [2] 
 
18.  
(a) Name the deficiency for which first clinical gene therapy was given. 
(b) Mention the cause of and one cure for this deficiency.  [2] 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
 
CBSE XII  |  Biology 
Board Paper 2013 – Delhi – Set 3 
 
     
 
SECTION C 
19.  
(a) Why is human ABO blood group gene considered a good example of multiple 
alleles? 
(b) Work out a cross up to F 1 generation only, between a mother with blood group A 
(Homozygous) and the father with blood group B (Homozygous). Explain the 
pattern of inheritance exhibited.  [3] 
 
20.  Describe the structure of RNA polynucleotide chain having four different types of 
nucleotides.  [3] 
 
21.  
(a) Differentiate between inbreeding and outbreeding. 
(b) Explain inbreeding depression and how it can be overcome. 
(c) Mention two advantages of inbreeding programme in cattle.  [3] 
 
22.  
(a) Why are the fruit juices bought from market clearer as compared to those made 
at home? 
(b) Name the bioactive molecules produced by Trichoderma polysporum and 
Monascus purpureus.  [3] 
 
23. Draw the following diagrams related to human reproduction and label them. 
(a) The zygote after the first cleavage division 
(b) Morula stage 
(c) Blastocyst stage (sectional view)  [3] 
 
24.  With the help of any two suitable examples explain the effect of anthropogenic 
actions on organic evolution.  [3] 
 
25.  How have human activities caused desertification? Explain. 
OR 
              How does algal bloom destroy the quality of a fresh water body? Explain.  [3] 
 
26.  Explain mutualism with the help of any two examples. How is it different from 
commensalism?  [3] 
 
27.  
(a) Why a transgenic animals so called? 
(b) Explain the role of transgenic animals in (i) Vaccine safety and (ii) Biological 
products with the help of an example each.  [3] 
 
 
 
Page 4


  
 
CBSE XII  |  Biology 
Board Paper 2013 – Delhi – Set 3 
 
     
CBSE 
 Class XII Biology 
Board Paper 2013 - Delhi (Set 3) 
 
Time: 3 hrs Total Marks: 70 
 
General Instruction: 
1. All questions are compulsory. 
2. This question paper consists of four Sections A, B C and D. Section A contains 8  
questions of one mark each, Section B is of 10 questions of two marks each, Section C is 
of 9 questions of three marks each, and Section D is of 3 questions of five marks each.  
3. There is no overall choice. However an internal choice has been provided in one  
question of 2 marks, one question of 3 marks and all the three questions of 5 marks 
weight age. A student has to attempt only one of the alternatives in such questions. 
4. Wherever necessary, the diagrams drawn should be neat and properly labelled. 
 
SECTION A 
 
1. Why is the enzyme cellulase needed for isolating genetic material from plant cells 
and not form the animal cells? [1] 
 
2. Write the importance of MOET.  [1] 
 
 
3. An anther with malfunctioning tapetum often fails to produce viable male 
gametophytes. Give any one reason.  [1] 
 
 
4. Why sharing of injection needles between two individuals are not recommended? [1] 
 
 
5. Name the enzyme and state its property that is responsible for continuous and 
discontinuous replication of the two strands of a DNA molecule. [1] 
 
 
6. “Sweet potato tubers and potato tubers are the result of convergent evolution.” 
Justify the statement.  [1] 
 
7. Write the equation that helps in deriving the net primary productivity of an 
ecosystem.  [1] 
 
8. Name the type biodiversity represented by the following:  [1] 
(a) 50,000 different strains of rice in India. 
(b) Estuaries and alpine meadows in India 
 
 
 
 
 
  
 
CBSE XII  |  Biology 
Board Paper 2013 – Delhi – Set 3 
 
     
 
SECTION B 
 
9. Explain why very small animals are rarely found in polar region.  [2] 
 
10. Why the pyramid of energy is always upright? Explain.  [2] 
 
11. Expand the following and mention one application of each: 
1) PCR 
2) ELISA 
OR 
 
(a) Mention the difference in the mode of action of exonuclease and endonuclease. 
(b) How does restriction endonuclease function?  [2] 
 
12. Name any two sources of e-Wastes and write two difference ways of their disposal. [2] 
 
13.  Explain the steps that ensure cross pollination in an autogamous flower.  [2] 
 
14.  When and where do chorionic villi appear in humans? State their function.  [2] 
 
15.  In a cross between two tall pea plants some of the offsprings produced were dwarf. 
Show with the help of Punett square how this is possible.  [2] 
16.  A student on a school picnic to park on a windy day started sneezing and having 
difficulty in breathing in reaching the park. The teacher enquired whether the 
student was allergic to something. 
(a) What is an allergy? 
(b) Write the two unique characteristics of the system involved in the response 
observed in the student.  [2] 
 
17.  Why and how bacteria can be made ‘competent’?  [2] 
 
18.  
(a) Name the deficiency for which first clinical gene therapy was given. 
(b) Mention the cause of and one cure for this deficiency.  [2] 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
 
CBSE XII  |  Biology 
Board Paper 2013 – Delhi – Set 3 
 
     
 
SECTION C 
19.  
(a) Why is human ABO blood group gene considered a good example of multiple 
alleles? 
(b) Work out a cross up to F 1 generation only, between a mother with blood group A 
(Homozygous) and the father with blood group B (Homozygous). Explain the 
pattern of inheritance exhibited.  [3] 
 
20.  Describe the structure of RNA polynucleotide chain having four different types of 
nucleotides.  [3] 
 
21.  
(a) Differentiate between inbreeding and outbreeding. 
(b) Explain inbreeding depression and how it can be overcome. 
(c) Mention two advantages of inbreeding programme in cattle.  [3] 
 
22.  
(a) Why are the fruit juices bought from market clearer as compared to those made 
at home? 
(b) Name the bioactive molecules produced by Trichoderma polysporum and 
Monascus purpureus.  [3] 
 
23. Draw the following diagrams related to human reproduction and label them. 
(a) The zygote after the first cleavage division 
(b) Morula stage 
(c) Blastocyst stage (sectional view)  [3] 
 
24.  With the help of any two suitable examples explain the effect of anthropogenic 
actions on organic evolution.  [3] 
 
25.  How have human activities caused desertification? Explain. 
OR 
              How does algal bloom destroy the quality of a fresh water body? Explain.  [3] 
 
26.  Explain mutualism with the help of any two examples. How is it different from 
commensalism?  [3] 
 
27.  
(a) Why a transgenic animals so called? 
(b) Explain the role of transgenic animals in (i) Vaccine safety and (ii) Biological 
products with the help of an example each.  [3] 
 
 
 
  
 
CBSE XII  |  Biology 
Board Paper 2013 – Delhi – Set 3 
 
     
 
SECTION D 
 
28.  A child suffering from Thalassemia is born to a normal couple. But the mother is 
being blamed by the family for delivering a sick baby. [5] 
(a) What is Thalassemia? 
(b) How would you counsel the family not to blame the mother for delivering a child 
suffering from this disease? Explain. 
(c) List the values your counselling can propagate in the families. 
 
29.  
(a) Draw a diagram of a mature embryo sac of an angiosperm and label the 
following parts in it. [5] 
(i) Filiform apparatus 
(ii) Synergids 
(iii) Central cell 
(iv) Egg cell 
(v) Polar nuclei 
(vi) Antipodals 
 
(b) Write the fate of egg cell and polar nuclei after fertilization. 
OR 
(a) Describe the events of Oogenesis with the help of schematic representation. 
(b) Write two differences between Oogensis and spermatogenesis. 
 
 
30.  Describe the asexual and sexual phases of life cycle of Plasmodium that causes 
malaria in humans.  [5] 
OR 
(a) What is plant breeding? List the two steps the classical plant breeding involves. 
(b) How has the mutation breeding helped in improving crop varieties? Give one 
example where this technique has helped. 
(c) How has the breeding programme helped in improving the public nutritional 
health? State two examples in support of your answer.