CBSE Biology Past year paper Delhi (Set - 3) - 2011, Class 12 | Additional Study Material for NEET PDF Download

 Page 1


  
 
CBSE XII  |  Biology 
Board Paper 2011 – Delhi – Set 3 
 
     
CBSE  
 Class XII Biology (Theory) 
Board Paper 2011 – 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. Mention the role of the codons AUG and UGA during protein synthesis. [1] 
 
2. Normally one embryo develops in one seed but when an orange seed is squeezed many 
embryos of different shapes and sizes are seen.  Mention how it has happened. [1] 
 
3. Why green plants are not found beyond a certain depth in the ocean? [1] 
 
4. Write the scientific name of the microbe used for fermenting malted cereals and fruit 
juices. [1] 
 
5. Name the type of cell division that takes place in the zygote of an organism exhibiting 
haplontic life cycle. [1] 
 
6. How can bacterial DNA be released from the bacterial cell for biotechnology 
experiments? [1] 
 
7. Name the event during cell division cycle that results in the gain or loss of  
chromosome. [1] 
 
8. Write the importance of cryopreservation in conservation of biodiversity. [1] 
  
Page 2


  
 
CBSE XII  |  Biology 
Board Paper 2011 – Delhi – Set 3 
 
     
CBSE  
 Class XII Biology (Theory) 
Board Paper 2011 – 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. Mention the role of the codons AUG and UGA during protein synthesis. [1] 
 
2. Normally one embryo develops in one seed but when an orange seed is squeezed many 
embryos of different shapes and sizes are seen.  Mention how it has happened. [1] 
 
3. Why green plants are not found beyond a certain depth in the ocean? [1] 
 
4. Write the scientific name of the microbe used for fermenting malted cereals and fruit 
juices. [1] 
 
5. Name the type of cell division that takes place in the zygote of an organism exhibiting 
haplontic life cycle. [1] 
 
6. How can bacterial DNA be released from the bacterial cell for biotechnology 
experiments? [1] 
 
7. Name the event during cell division cycle that results in the gain or loss of  
chromosome. [1] 
 
8. Write the importance of cryopreservation in conservation of biodiversity. [1] 
  
  
 
CBSE XII  |  Biology 
Board Paper 2011 – Delhi – Set 3 
 
     
SECTION B 
9. State the dual role of deoxyribonucleoside triphosphates during DNA replication. [2] 
 
10. Differentiate between albuminous and non-albuminous seeds, giving one example of 
each. [2] 
 
11. Explain how a hereditary disease can be corrected. Give an example of first successful 
attempt made towards correction of such diseases. [2] 
 
12. Justify with the help of an example where a deliberate attempt by humans has led to the 
extinction of a particular species. [2] 
 
13. Explain the role of Ti plasmids in biotechnology. [2] 
 
14. Study the graph given below. Explain how is oxygen concentration affected in the river 
when sewage is discharged into it. [2] 
 
 
15. Name the two types of immune systems in a human body. Why are cell mediated and 
humoral immunities so called? [2] 
OR 
Write the scientific names of the causal organisms of elephantiasis and ringworm in 
humans. Mention the body parts affected by them. 
 
16.  State the functions of primary and secondary lymphoid organs in humans. [2] 
 
17. Why is CuT considered a good contraceptive device to space children? [2] 
 
18.  Explain the process of RNA interference. [2] 
  
Page 3


  
 
CBSE XII  |  Biology 
Board Paper 2011 – Delhi – Set 3 
 
     
CBSE  
 Class XII Biology (Theory) 
Board Paper 2011 – 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. Mention the role of the codons AUG and UGA during protein synthesis. [1] 
 
2. Normally one embryo develops in one seed but when an orange seed is squeezed many 
embryos of different shapes and sizes are seen.  Mention how it has happened. [1] 
 
3. Why green plants are not found beyond a certain depth in the ocean? [1] 
 
4. Write the scientific name of the microbe used for fermenting malted cereals and fruit 
juices. [1] 
 
5. Name the type of cell division that takes place in the zygote of an organism exhibiting 
haplontic life cycle. [1] 
 
6. How can bacterial DNA be released from the bacterial cell for biotechnology 
experiments? [1] 
 
7. Name the event during cell division cycle that results in the gain or loss of  
chromosome. [1] 
 
8. Write the importance of cryopreservation in conservation of biodiversity. [1] 
  
  
 
CBSE XII  |  Biology 
Board Paper 2011 – Delhi – Set 3 
 
     
SECTION B 
9. State the dual role of deoxyribonucleoside triphosphates during DNA replication. [2] 
 
10. Differentiate between albuminous and non-albuminous seeds, giving one example of 
each. [2] 
 
11. Explain how a hereditary disease can be corrected. Give an example of first successful 
attempt made towards correction of such diseases. [2] 
 
12. Justify with the help of an example where a deliberate attempt by humans has led to the 
extinction of a particular species. [2] 
 
13. Explain the role of Ti plasmids in biotechnology. [2] 
 
14. Study the graph given below. Explain how is oxygen concentration affected in the river 
when sewage is discharged into it. [2] 
 
 
15. Name the two types of immune systems in a human body. Why are cell mediated and 
humoral immunities so called? [2] 
OR 
Write the scientific names of the causal organisms of elephantiasis and ringworm in 
humans. Mention the body parts affected by them. 
 
16.  State the functions of primary and secondary lymphoid organs in humans. [2] 
 
17. Why is CuT considered a good contraceptive device to space children? [2] 
 
18.  Explain the process of RNA interference. [2] 
  
  
 
CBSE XII  |  Biology 
Board Paper 2011 – Delhi – Set 3 
 
     
SECTION C 
19.  
(a) Identify (A) and (B) illustrations in the following: [3] 
 
 
(b) Write the term given to (A) and (C) and why? 
(c) Expand PCR. Mention its importance in biotechnology. 
 
20. Name the type of interaction seen in each of the following examples: [3] 
(i) Ascaris worms living in the intestine of human 
(ii) Wasp pollinating fig inflorescence 
(iii) Clown fish living among the tentacles of sea-anemone 
(iv) Mycorrhizae living on the roots of higher plants 
(v) Orchid growing on a branch of a mango tree 
(vi) Disappearance of smaller barnacles when Balanus dominated in the Coast of 
Scotland 
 
21.    [3] 
 
Why do you see two different types of replicating strands in the given DNA replication 
form? Explain. Name these strands. 
 
Page 4


  
 
CBSE XII  |  Biology 
Board Paper 2011 – Delhi – Set 3 
 
     
CBSE  
 Class XII Biology (Theory) 
Board Paper 2011 – 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. Mention the role of the codons AUG and UGA during protein synthesis. [1] 
 
2. Normally one embryo develops in one seed but when an orange seed is squeezed many 
embryos of different shapes and sizes are seen.  Mention how it has happened. [1] 
 
3. Why green plants are not found beyond a certain depth in the ocean? [1] 
 
4. Write the scientific name of the microbe used for fermenting malted cereals and fruit 
juices. [1] 
 
5. Name the type of cell division that takes place in the zygote of an organism exhibiting 
haplontic life cycle. [1] 
 
6. How can bacterial DNA be released from the bacterial cell for biotechnology 
experiments? [1] 
 
7. Name the event during cell division cycle that results in the gain or loss of  
chromosome. [1] 
 
8. Write the importance of cryopreservation in conservation of biodiversity. [1] 
  
  
 
CBSE XII  |  Biology 
Board Paper 2011 – Delhi – Set 3 
 
     
SECTION B 
9. State the dual role of deoxyribonucleoside triphosphates during DNA replication. [2] 
 
10. Differentiate between albuminous and non-albuminous seeds, giving one example of 
each. [2] 
 
11. Explain how a hereditary disease can be corrected. Give an example of first successful 
attempt made towards correction of such diseases. [2] 
 
12. Justify with the help of an example where a deliberate attempt by humans has led to the 
extinction of a particular species. [2] 
 
13. Explain the role of Ti plasmids in biotechnology. [2] 
 
14. Study the graph given below. Explain how is oxygen concentration affected in the river 
when sewage is discharged into it. [2] 
 
 
15. Name the two types of immune systems in a human body. Why are cell mediated and 
humoral immunities so called? [2] 
OR 
Write the scientific names of the causal organisms of elephantiasis and ringworm in 
humans. Mention the body parts affected by them. 
 
16.  State the functions of primary and secondary lymphoid organs in humans. [2] 
 
17. Why is CuT considered a good contraceptive device to space children? [2] 
 
18.  Explain the process of RNA interference. [2] 
  
  
 
CBSE XII  |  Biology 
Board Paper 2011 – Delhi – Set 3 
 
     
SECTION C 
19.  
(a) Identify (A) and (B) illustrations in the following: [3] 
 
 
(b) Write the term given to (A) and (C) and why? 
(c) Expand PCR. Mention its importance in biotechnology. 
 
20. Name the type of interaction seen in each of the following examples: [3] 
(i) Ascaris worms living in the intestine of human 
(ii) Wasp pollinating fig inflorescence 
(iii) Clown fish living among the tentacles of sea-anemone 
(iv) Mycorrhizae living on the roots of higher plants 
(v) Orchid growing on a branch of a mango tree 
(vi) Disappearance of smaller barnacles when Balanus dominated in the Coast of 
Scotland 
 
21.    [3] 
 
Why do you see two different types of replicating strands in the given DNA replication 
form? Explain. Name these strands. 
 
  
 
CBSE XII  |  Biology 
Board Paper 2011 – Delhi – Set 3 
 
     
22. Draw a diagram of a male gametophyte of an angiosperm. Label any four parts. Why is 
sporopollenin considered the most resistant organic material? [3] 
 
23.  How are dominance, co-dominance and incomplete dominance patterns of inheritance 
different from each other? [3] 
 
24.    [3] 
(a) Sickle celled anaemia in humans is a result of point mutation. Explain. 
(b) Write the genotypes of both the parents who have produced a sickle celled anaemic 
offspring. 
 
25.     [3] 
(a) Why do farmers prefer biofertilisers to chemical fertilizers these days? Explain. 
(b) How do Anabaena and Mycorrhiza act as biofertilisers? 
 
26.    [3] 
(a) Name the stage of Plasmodium that gains entry into the human body. 
(b) Trace the stages of Plasmodium in the body of female Anopheles after its entry. 
(c) Explain the cause of periodic recurrence of chill and high fever during malarial 
attack in humans. 
OR 
Trace the events that occur in human body to cause immunodeficiency when HIV gains 
entry into the body. 
 
27.  What is inbreeding depression and how is it caused in organisms? Write any two 
advantages of inbreeding.   [3] 
 
 
 
  
Page 5


  
 
CBSE XII  |  Biology 
Board Paper 2011 – Delhi – Set 3 
 
     
CBSE  
 Class XII Biology (Theory) 
Board Paper 2011 – 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. Mention the role of the codons AUG and UGA during protein synthesis. [1] 
 
2. Normally one embryo develops in one seed but when an orange seed is squeezed many 
embryos of different shapes and sizes are seen.  Mention how it has happened. [1] 
 
3. Why green plants are not found beyond a certain depth in the ocean? [1] 
 
4. Write the scientific name of the microbe used for fermenting malted cereals and fruit 
juices. [1] 
 
5. Name the type of cell division that takes place in the zygote of an organism exhibiting 
haplontic life cycle. [1] 
 
6. How can bacterial DNA be released from the bacterial cell for biotechnology 
experiments? [1] 
 
7. Name the event during cell division cycle that results in the gain or loss of  
chromosome. [1] 
 
8. Write the importance of cryopreservation in conservation of biodiversity. [1] 
  
  
 
CBSE XII  |  Biology 
Board Paper 2011 – Delhi – Set 3 
 
     
SECTION B 
9. State the dual role of deoxyribonucleoside triphosphates during DNA replication. [2] 
 
10. Differentiate between albuminous and non-albuminous seeds, giving one example of 
each. [2] 
 
11. Explain how a hereditary disease can be corrected. Give an example of first successful 
attempt made towards correction of such diseases. [2] 
 
12. Justify with the help of an example where a deliberate attempt by humans has led to the 
extinction of a particular species. [2] 
 
13. Explain the role of Ti plasmids in biotechnology. [2] 
 
14. Study the graph given below. Explain how is oxygen concentration affected in the river 
when sewage is discharged into it. [2] 
 
 
15. Name the two types of immune systems in a human body. Why are cell mediated and 
humoral immunities so called? [2] 
OR 
Write the scientific names of the causal organisms of elephantiasis and ringworm in 
humans. Mention the body parts affected by them. 
 
16.  State the functions of primary and secondary lymphoid organs in humans. [2] 
 
17. Why is CuT considered a good contraceptive device to space children? [2] 
 
18.  Explain the process of RNA interference. [2] 
  
  
 
CBSE XII  |  Biology 
Board Paper 2011 – Delhi – Set 3 
 
     
SECTION C 
19.  
(a) Identify (A) and (B) illustrations in the following: [3] 
 
 
(b) Write the term given to (A) and (C) and why? 
(c) Expand PCR. Mention its importance in biotechnology. 
 
20. Name the type of interaction seen in each of the following examples: [3] 
(i) Ascaris worms living in the intestine of human 
(ii) Wasp pollinating fig inflorescence 
(iii) Clown fish living among the tentacles of sea-anemone 
(iv) Mycorrhizae living on the roots of higher plants 
(v) Orchid growing on a branch of a mango tree 
(vi) Disappearance of smaller barnacles when Balanus dominated in the Coast of 
Scotland 
 
21.    [3] 
 
Why do you see two different types of replicating strands in the given DNA replication 
form? Explain. Name these strands. 
 
  
 
CBSE XII  |  Biology 
Board Paper 2011 – Delhi – Set 3 
 
     
22. Draw a diagram of a male gametophyte of an angiosperm. Label any four parts. Why is 
sporopollenin considered the most resistant organic material? [3] 
 
23.  How are dominance, co-dominance and incomplete dominance patterns of inheritance 
different from each other? [3] 
 
24.    [3] 
(a) Sickle celled anaemia in humans is a result of point mutation. Explain. 
(b) Write the genotypes of both the parents who have produced a sickle celled anaemic 
offspring. 
 
25.     [3] 
(a) Why do farmers prefer biofertilisers to chemical fertilizers these days? Explain. 
(b) How do Anabaena and Mycorrhiza act as biofertilisers? 
 
26.    [3] 
(a) Name the stage of Plasmodium that gains entry into the human body. 
(b) Trace the stages of Plasmodium in the body of female Anopheles after its entry. 
(c) Explain the cause of periodic recurrence of chill and high fever during malarial 
attack in humans. 
OR 
Trace the events that occur in human body to cause immunodeficiency when HIV gains 
entry into the body. 
 
27.  What is inbreeding depression and how is it caused in organisms? Write any two 
advantages of inbreeding.   [3] 
 
 
 
  
  
 
CBSE XII  |  Biology 
Board Paper 2011 – Delhi – Set 3 
 
     
SECTION D 
28.    [5] 
(a) Describe the stages of oogenesis in human females. 
(b) Draw a labelled diagram of human ovum released after ovulation. 
OR 
(a) When and where does spermatogenesis occur in a human male? 
(b) Draw a diagram of a mature human male gamete. Label the following parts: 
acrosome, nucleus, middle piece and tail. 
(c) Mention the functions of acrosome and middle piece. 
 
29.    [5] 
(a) Explain primary productivity and the factors that influence it. 
(b) Describe how do oxygen and chemical composition of detritus control 
decomposition? 
OR 
(a) What is El Nino effect? Explain how it accounts for biodiversity loss. 
(b) Explain any three measures that you as an individual would take, to reduce 
environmental pollution. 
 
30. Explain the salient features of Hugo de Vries theory of mutation. How is Darwin’s 
theory of natural selection different from it? Explain. [5] 
OR 
(a) Name the primates that lived about 15 million years ago. List their characteristic 
features. 
(b)  
(i) Where was the first man-like animal found? 
(ii) Write the order in which Neanderthals, Homo habilis and Homo 
erectus appeared on earth. State the brain capacity of each one of them. 
(iii) When did modern Homo sapiens appear on this planet?