CBSE Biology Past year paper Delhi (Set - 3) - 2012, Class 12 | Additional Study Material for NEET PDF Download

 Page 1


  
 
CBSE XII  |  Biology 
Board Paper 2012 – Delhi – Set 3 
 
     
CBSE 
Class XII Biology (Theory) 
Board Paper 2012 – 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 difference between the Spermiogensis and spermiation. [1] 
 
2. A garden pea plant (A) produced inflated yellow pod, and another plant (B) of the same 
species produced Constricted green pods. Identify the dominant traits. [1] 
 
3. What is an interaction called when an orchid grows on a mango plant? [1]  
 
4. Write the names of two semi-dwarf and high yielding rice varieties developed in  
India after 1966. [1] 
 
5. Write what do phytophagous insects feed on. [1]  
 
6. Mention the unique feature with respect to flowering and fruiting in bamboo species. [1] 
 
7. How does smoking tobacco in human lead to oxygen deficiency in their body? [1]  
 
8. State the significance of biochemical similarities amongst diverse organism in  
evolution. [1] 
 
 
  
Page 2


  
 
CBSE XII  |  Biology 
Board Paper 2012 – Delhi – Set 3 
 
     
CBSE 
Class XII Biology (Theory) 
Board Paper 2012 – 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 difference between the Spermiogensis and spermiation. [1] 
 
2. A garden pea plant (A) produced inflated yellow pod, and another plant (B) of the same 
species produced Constricted green pods. Identify the dominant traits. [1] 
 
3. What is an interaction called when an orchid grows on a mango plant? [1]  
 
4. Write the names of two semi-dwarf and high yielding rice varieties developed in  
India after 1966. [1] 
 
5. Write what do phytophagous insects feed on. [1]  
 
6. Mention the unique feature with respect to flowering and fruiting in bamboo species. [1] 
 
7. How does smoking tobacco in human lead to oxygen deficiency in their body? [1]  
 
8. State the significance of biochemical similarities amongst diverse organism in  
evolution. [1] 
 
 
  
  
 
CBSE XII  |  Biology 
Board Paper 2012 – Delhi – Set 3 
 
     
SECTION B 
 
9. Explain the work carried out by Cohen and Boyer that contributed immensely in 
biotechnology.  [2] 
   
10.  [2] 
(a) State the difference between meiocyte and gamete with respect to chromosome 
number. 
(b) Why is a whiptail lizard referred to as parthenogenetic?  
 
11. Draw a neat labelled sketch of a replicating fork of DNA. [2]  
 
12. Some organisms suspend their metabolic activities to survive in unfavourable 
conditions. Explain with the help of any four examples.  [2] 
   
13.  [2] 
(a) State the role of DNA ligase in biotechnology.  
(b) What happens when Meloidegyne incognitia consumes cells with RNAi gene?  
 
 
14. Where is sporopollenin present in plants? State its significance with reference to its  
chemical nature.  [2] 
 
15. Mention the importance of Lactic acid bacteria to humans other than setting milk into 
curd.  [2] 
OR 
How do methanogens help in producing biogas?  
 
16.    [2] 
(a) Name the Protozoan parasite that causes amoebic dysentery in humans. 
(b) Mention two diagnostic symptoms of the disease.  
(c) How is this disease transmitted to others? 
 
17.          [2] 
(a) Highlight the role of thymus as a lymphoid organ.  
(b) Name the cells that are released from the above mentioned gland. Mention how they 
help in immunity. 
 
18.  Why do Clown fish and sea anemone pair up? What is this relationship called? [2] 
 
 
 
 
 
 
 
  
Page 3


  
 
CBSE XII  |  Biology 
Board Paper 2012 – Delhi – Set 3 
 
     
CBSE 
Class XII Biology (Theory) 
Board Paper 2012 – 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 difference between the Spermiogensis and spermiation. [1] 
 
2. A garden pea plant (A) produced inflated yellow pod, and another plant (B) of the same 
species produced Constricted green pods. Identify the dominant traits. [1] 
 
3. What is an interaction called when an orchid grows on a mango plant? [1]  
 
4. Write the names of two semi-dwarf and high yielding rice varieties developed in  
India after 1966. [1] 
 
5. Write what do phytophagous insects feed on. [1]  
 
6. Mention the unique feature with respect to flowering and fruiting in bamboo species. [1] 
 
7. How does smoking tobacco in human lead to oxygen deficiency in their body? [1]  
 
8. State the significance of biochemical similarities amongst diverse organism in  
evolution. [1] 
 
 
  
  
 
CBSE XII  |  Biology 
Board Paper 2012 – Delhi – Set 3 
 
     
SECTION B 
 
9. Explain the work carried out by Cohen and Boyer that contributed immensely in 
biotechnology.  [2] 
   
10.  [2] 
(a) State the difference between meiocyte and gamete with respect to chromosome 
number. 
(b) Why is a whiptail lizard referred to as parthenogenetic?  
 
11. Draw a neat labelled sketch of a replicating fork of DNA. [2]  
 
12. Some organisms suspend their metabolic activities to survive in unfavourable 
conditions. Explain with the help of any four examples.  [2] 
   
13.  [2] 
(a) State the role of DNA ligase in biotechnology.  
(b) What happens when Meloidegyne incognitia consumes cells with RNAi gene?  
 
 
14. Where is sporopollenin present in plants? State its significance with reference to its  
chemical nature.  [2] 
 
15. Mention the importance of Lactic acid bacteria to humans other than setting milk into 
curd.  [2] 
OR 
How do methanogens help in producing biogas?  
 
16.    [2] 
(a) Name the Protozoan parasite that causes amoebic dysentery in humans. 
(b) Mention two diagnostic symptoms of the disease.  
(c) How is this disease transmitted to others? 
 
17.          [2] 
(a) Highlight the role of thymus as a lymphoid organ.  
(b) Name the cells that are released from the above mentioned gland. Mention how they 
help in immunity. 
 
18.  Why do Clown fish and sea anemone pair up? What is this relationship called? [2] 
 
 
 
 
 
 
 
  
  
 
CBSE XII  |  Biology 
Board Paper 2012 – Delhi – Set 3 
 
     
SECTION C 
 
19.           [3] 
(a) Construct a complete transcription unit with promotor and terminator on the basis 
of the hypothetical template strand given below:  
 
 
(b) Write the RNA strand transcribed from the above transcription unit along with its 
polarity.  
OR 
How are the structural genes inactivated in lac operon in E. Coli? Explain.  
 
20.  Write the function of each of the following:  [3] 
(a) Seminal vesicle 
(b) Scutellum  
(c) Acrosome of human sperm. 
 
21.  Study a part of the life cycle of malarial parasite given below. Answer the questions  
              that follows: [3] 
 
 
 
(a) Mention the roles of 'A' in the life cycle of the malarial parasite.  
(b) Name the event 'C' and the organ where this event occurs.  
(c) Identify the organ 'B' and name the cells being released from it. 
 
22. Draw a schematic sketch of pBR 322 plasmid and label the following in it: [3] 
(a) Any two restriction sites.  
(b) Ori and rop genes.  
(c) An antibiotic resistant gene. 
Page 4


  
 
CBSE XII  |  Biology 
Board Paper 2012 – Delhi – Set 3 
 
     
CBSE 
Class XII Biology (Theory) 
Board Paper 2012 – 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 difference between the Spermiogensis and spermiation. [1] 
 
2. A garden pea plant (A) produced inflated yellow pod, and another plant (B) of the same 
species produced Constricted green pods. Identify the dominant traits. [1] 
 
3. What is an interaction called when an orchid grows on a mango plant? [1]  
 
4. Write the names of two semi-dwarf and high yielding rice varieties developed in  
India after 1966. [1] 
 
5. Write what do phytophagous insects feed on. [1]  
 
6. Mention the unique feature with respect to flowering and fruiting in bamboo species. [1] 
 
7. How does smoking tobacco in human lead to oxygen deficiency in their body? [1]  
 
8. State the significance of biochemical similarities amongst diverse organism in  
evolution. [1] 
 
 
  
  
 
CBSE XII  |  Biology 
Board Paper 2012 – Delhi – Set 3 
 
     
SECTION B 
 
9. Explain the work carried out by Cohen and Boyer that contributed immensely in 
biotechnology.  [2] 
   
10.  [2] 
(a) State the difference between meiocyte and gamete with respect to chromosome 
number. 
(b) Why is a whiptail lizard referred to as parthenogenetic?  
 
11. Draw a neat labelled sketch of a replicating fork of DNA. [2]  
 
12. Some organisms suspend their metabolic activities to survive in unfavourable 
conditions. Explain with the help of any four examples.  [2] 
   
13.  [2] 
(a) State the role of DNA ligase in biotechnology.  
(b) What happens when Meloidegyne incognitia consumes cells with RNAi gene?  
 
 
14. Where is sporopollenin present in plants? State its significance with reference to its  
chemical nature.  [2] 
 
15. Mention the importance of Lactic acid bacteria to humans other than setting milk into 
curd.  [2] 
OR 
How do methanogens help in producing biogas?  
 
16.    [2] 
(a) Name the Protozoan parasite that causes amoebic dysentery in humans. 
(b) Mention two diagnostic symptoms of the disease.  
(c) How is this disease transmitted to others? 
 
17.          [2] 
(a) Highlight the role of thymus as a lymphoid organ.  
(b) Name the cells that are released from the above mentioned gland. Mention how they 
help in immunity. 
 
18.  Why do Clown fish and sea anemone pair up? What is this relationship called? [2] 
 
 
 
 
 
 
 
  
  
 
CBSE XII  |  Biology 
Board Paper 2012 – Delhi – Set 3 
 
     
SECTION C 
 
19.           [3] 
(a) Construct a complete transcription unit with promotor and terminator on the basis 
of the hypothetical template strand given below:  
 
 
(b) Write the RNA strand transcribed from the above transcription unit along with its 
polarity.  
OR 
How are the structural genes inactivated in lac operon in E. Coli? Explain.  
 
20.  Write the function of each of the following:  [3] 
(a) Seminal vesicle 
(b) Scutellum  
(c) Acrosome of human sperm. 
 
21.  Study a part of the life cycle of malarial parasite given below. Answer the questions  
              that follows: [3] 
 
 
 
(a) Mention the roles of 'A' in the life cycle of the malarial parasite.  
(b) Name the event 'C' and the organ where this event occurs.  
(c) Identify the organ 'B' and name the cells being released from it. 
 
22. Draw a schematic sketch of pBR 322 plasmid and label the following in it: [3] 
(a) Any two restriction sites.  
(b) Ori and rop genes.  
(c) An antibiotic resistant gene. 
  
 
CBSE XII  |  Biology 
Board Paper 2012 – Delhi – Set 3 
 
     
23. State the theory of Biogenesis. How does Miller's experiment support this theory?  [3]  
 
24. Given below is the representation of amino acid composition of the relevant translated 
portion of ß-chain of haemoglobin, related to the shape of human red blood cells.  [3] 
 
 
 
(a) Is this representation indicating a normal human or a sufferer from certain related 
genetic disease? Give reason in support of your answer.  
 
(b) What difference would be noticed in the phenotype of the normal and the sufferer 
related to this gene?  
 
(c) Who are likely to suffer more from the defect related to the gene represented - the 
males, the females or both males and females equally? And why? 
 
25.      [3] 
(a) Why are the colourful polysterene and plastic packagings used for protecting the 
food, considered an environmental menace?  
 
(b) Write about the remedy found for the efficient use of plastic waste by Ahmed Khan 
of Bangalore.  
 
26.  Name of the genes responsible for the making Bt cotton plants resistant to bollworm 
attack. How do such plants attain resistance against bollworm attacks? Explain. [3] 
 
27. Name of the two different categories of microbes naturally occurring in sewage water. 
Explain their role in cleaning sewage water into usable water. [3] 
 
  
Page 5


  
 
CBSE XII  |  Biology 
Board Paper 2012 – Delhi – Set 3 
 
     
CBSE 
Class XII Biology (Theory) 
Board Paper 2012 – 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 difference between the Spermiogensis and spermiation. [1] 
 
2. A garden pea plant (A) produced inflated yellow pod, and another plant (B) of the same 
species produced Constricted green pods. Identify the dominant traits. [1] 
 
3. What is an interaction called when an orchid grows on a mango plant? [1]  
 
4. Write the names of two semi-dwarf and high yielding rice varieties developed in  
India after 1966. [1] 
 
5. Write what do phytophagous insects feed on. [1]  
 
6. Mention the unique feature with respect to flowering and fruiting in bamboo species. [1] 
 
7. How does smoking tobacco in human lead to oxygen deficiency in their body? [1]  
 
8. State the significance of biochemical similarities amongst diverse organism in  
evolution. [1] 
 
 
  
  
 
CBSE XII  |  Biology 
Board Paper 2012 – Delhi – Set 3 
 
     
SECTION B 
 
9. Explain the work carried out by Cohen and Boyer that contributed immensely in 
biotechnology.  [2] 
   
10.  [2] 
(a) State the difference between meiocyte and gamete with respect to chromosome 
number. 
(b) Why is a whiptail lizard referred to as parthenogenetic?  
 
11. Draw a neat labelled sketch of a replicating fork of DNA. [2]  
 
12. Some organisms suspend their metabolic activities to survive in unfavourable 
conditions. Explain with the help of any four examples.  [2] 
   
13.  [2] 
(a) State the role of DNA ligase in biotechnology.  
(b) What happens when Meloidegyne incognitia consumes cells with RNAi gene?  
 
 
14. Where is sporopollenin present in plants? State its significance with reference to its  
chemical nature.  [2] 
 
15. Mention the importance of Lactic acid bacteria to humans other than setting milk into 
curd.  [2] 
OR 
How do methanogens help in producing biogas?  
 
16.    [2] 
(a) Name the Protozoan parasite that causes amoebic dysentery in humans. 
(b) Mention two diagnostic symptoms of the disease.  
(c) How is this disease transmitted to others? 
 
17.          [2] 
(a) Highlight the role of thymus as a lymphoid organ.  
(b) Name the cells that are released from the above mentioned gland. Mention how they 
help in immunity. 
 
18.  Why do Clown fish and sea anemone pair up? What is this relationship called? [2] 
 
 
 
 
 
 
 
  
  
 
CBSE XII  |  Biology 
Board Paper 2012 – Delhi – Set 3 
 
     
SECTION C 
 
19.           [3] 
(a) Construct a complete transcription unit with promotor and terminator on the basis 
of the hypothetical template strand given below:  
 
 
(b) Write the RNA strand transcribed from the above transcription unit along with its 
polarity.  
OR 
How are the structural genes inactivated in lac operon in E. Coli? Explain.  
 
20.  Write the function of each of the following:  [3] 
(a) Seminal vesicle 
(b) Scutellum  
(c) Acrosome of human sperm. 
 
21.  Study a part of the life cycle of malarial parasite given below. Answer the questions  
              that follows: [3] 
 
 
 
(a) Mention the roles of 'A' in the life cycle of the malarial parasite.  
(b) Name the event 'C' and the organ where this event occurs.  
(c) Identify the organ 'B' and name the cells being released from it. 
 
22. Draw a schematic sketch of pBR 322 plasmid and label the following in it: [3] 
(a) Any two restriction sites.  
(b) Ori and rop genes.  
(c) An antibiotic resistant gene. 
  
 
CBSE XII  |  Biology 
Board Paper 2012 – Delhi – Set 3 
 
     
23. State the theory of Biogenesis. How does Miller's experiment support this theory?  [3]  
 
24. Given below is the representation of amino acid composition of the relevant translated 
portion of ß-chain of haemoglobin, related to the shape of human red blood cells.  [3] 
 
 
 
(a) Is this representation indicating a normal human or a sufferer from certain related 
genetic disease? Give reason in support of your answer.  
 
(b) What difference would be noticed in the phenotype of the normal and the sufferer 
related to this gene?  
 
(c) Who are likely to suffer more from the defect related to the gene represented - the 
males, the females or both males and females equally? And why? 
 
25.      [3] 
(a) Why are the colourful polysterene and plastic packagings used for protecting the 
food, considered an environmental menace?  
 
(b) Write about the remedy found for the efficient use of plastic waste by Ahmed Khan 
of Bangalore.  
 
26.  Name of the genes responsible for the making Bt cotton plants resistant to bollworm 
attack. How do such plants attain resistance against bollworm attacks? Explain. [3] 
 
27. Name of the two different categories of microbes naturally occurring in sewage water. 
Explain their role in cleaning sewage water into usable water. [3] 
 
  
  
 
CBSE XII  |  Biology 
Board Paper 2012 – Delhi – Set 3 
 
     
SECTION D 
 
28.  Explain the carbon cycle with the help of a simplified model. [5] 
OR 
Explain how does: 
(a) A primary succession starts on a bare rock and reach a climax community? 
(b) The algal bloom eventually choke the water body in an industrial area? 
 
29. The following is the illustration of the sequence of ovarian events (a-i) in a human 
female. [5] 
 
(i) Identify the figure that illustrates ovulation and mention the stage of oogenesis it 
represents. 
(ii) Name of the ovarian hormone and the pituitary hormone that have caused the 
above mentioned event. 
(iii) Explain the changes that occur in the uterus simultaneously in anticipation. 
(iv) Write the difference between the ‘c’ and ‘h’. 
(v) Draw a labeled sketch of the structure of a human ovum prior to fertilization. 
 
OR 
 
How does the megaspore mother cell develop into 7-celled, 8 nucleate embryo sac in 
an angiosperm? Draw a labeled diagram of a mature embryo sac. 
  
 
30. Name the scientists who proved experimentally that DNA is the genetic material.  
Describe their experiment.  [5] 
OR 
 
(a) List the three different allelic forms of gene 'I' in humans. Explain the different  
phenotypic expressions, controlled by these three forms.  
 
(b) A woman with blood group 'A' marries a man with blood group 'O'. Discuss  
the possibilities of the inheritance of the blood groups in the following starting  
with "yes" or "no" for each:  
(i) They produce children with blood group "A" only.  
(ii) They produce children some with "O" blood group and some with "A'  
blood group.