CBSE Biology All India Past year paper (Set - 3) - 2015, Class 12 | Additional Study Material for NEET PDF Download

 Page 1


  
 
CBSE XII  |  Biology 
Board Paper – 2015 – All India – Set 3 
 
     
 
CBSE 
Class XII Biology 
Board Paper 2015 – All India (Set 3) 
Time: 3 hrs Total Marks: 70 
 
General Instructions: 
1. There are total 26 questions and five sections in the question paper. All questions are 
compulsory. 
2. Section A contains questions number 1 to 5; very short answer type questions of 1 mark 
each. 
3. Section B contains questions number 6 to 10, short-answer type I questions of 2 marks 
each. 
4. Section C contains questions number 11 to 22, short answer type II questions of 3 marks 
each. 
5. Section D contains question number 23, value based question of 4 marks. 
6. Section E contains questions number 24 to 26, long-answer type questions of 5 marks 
each. 
7. There is no overall choice in the question paper; however, an internal choice is provided 
in one question of 2 marks, one question of 3 marks and all the three questions of 5 
marks. In these questions, an examinee is to attempt any of the two given alternatives. 
 
 
SECTION A 
 
1. What is a cistron? [1] 
 
2. How many chromosomes do drones of honeybee possess? Name the type of cell division 
involved in the production of sperms by them.  [1] 
 
3. List two advantages of the use of unleaded petrol in automobiles as fuel. [1] 
 
4. Retroviruses have no DNA. However, the DNA of the infected host cell does posses viral 
DNA. How is it possible? [1] 
 
5. Suggest any two possible treatments that can be given to a patient exhibiting adenosine 
deaminase deficiency. [1] 
 
 
 
 
 
 
Page 2


  
 
CBSE XII  |  Biology 
Board Paper – 2015 – All India – Set 3 
 
     
 
CBSE 
Class XII Biology 
Board Paper 2015 – All India (Set 3) 
Time: 3 hrs Total Marks: 70 
 
General Instructions: 
1. There are total 26 questions and five sections in the question paper. All questions are 
compulsory. 
2. Section A contains questions number 1 to 5; very short answer type questions of 1 mark 
each. 
3. Section B contains questions number 6 to 10, short-answer type I questions of 2 marks 
each. 
4. Section C contains questions number 11 to 22, short answer type II questions of 3 marks 
each. 
5. Section D contains question number 23, value based question of 4 marks. 
6. Section E contains questions number 24 to 26, long-answer type questions of 5 marks 
each. 
7. There is no overall choice in the question paper; however, an internal choice is provided 
in one question of 2 marks, one question of 3 marks and all the three questions of 5 
marks. In these questions, an examinee is to attempt any of the two given alternatives. 
 
 
SECTION A 
 
1. What is a cistron? [1] 
 
2. How many chromosomes do drones of honeybee possess? Name the type of cell division 
involved in the production of sperms by them.  [1] 
 
3. List two advantages of the use of unleaded petrol in automobiles as fuel. [1] 
 
4. Retroviruses have no DNA. However, the DNA of the infected host cell does posses viral 
DNA. How is it possible? [1] 
 
5. Suggest any two possible treatments that can be given to a patient exhibiting adenosine 
deaminase deficiency. [1] 
 
 
 
 
 
 
  
 
CBSE XII  |  Biology 
Board Paper – 2015 – All India – Set 3 
 
     
 
SECTION B 
 
6. Select two pairs from the following which exhibit divergent evolution. Give reasons for 
your answer. [2] 
(i) Forelimbs of cheetah and mammals 
(ii) Flippers of dolphins and penguins 
(iii) Wings of butterflies and birds 
(iv) Forelimbs of whales and mammals 
 
7. A liverwort plant is unable to complete its life cycle in a dry environment. State two 
reasons. [2] 
 
8. What is mutualism? Mention any two examples where the organisms involved are 
commercially exploited in agriculture. 
OR 
List any four techniques where the principle of ex-situ conservation of biodiversity has 
been employed. [2] 
 
9.   [2] 
(a) Why are the plants raised through micropropagation termed as somaclones? 
(b) Mention two advantages of this technique. 
 
10. Explain the function of “anaerobic sludge digester” in a sewage treatment plant. [2] 
 
SECTION C 
 
11. The F 2 progeny of a monohybrid cross showed phenotypic and genotypic ratio as 1:2:1 
unlike that the Mendel’s monohybrid F 2 ratio. With the help of a suitable example, work out 
a cross and explain how it is possible. [3] 
 
12. Why are some seeds referred to as apomictic seeds? Mention one advantage and one 
disadvantage to a farmer who uses them. [3] 
 
13. A heavily bleeding and bruised road accident victim was brought to a nursing home. The 
doctor immediately gave him an injection to protect him against a deadly disease. 
(a) Write what did the doctor inject into the patient’s body 
(b) How do you think this injection would protect the patient against the disease? 
(c) Name the disease against which the injection was given and the kind of immunity it 
provides. [3] 
 
14. “A very small sample of tissue or even a drop of blood can help determine paternity”. 
Provide a scientific explanation to substantiate the statement. [3] 
Page 3


  
 
CBSE XII  |  Biology 
Board Paper – 2015 – All India – Set 3 
 
     
 
CBSE 
Class XII Biology 
Board Paper 2015 – All India (Set 3) 
Time: 3 hrs Total Marks: 70 
 
General Instructions: 
1. There are total 26 questions and five sections in the question paper. All questions are 
compulsory. 
2. Section A contains questions number 1 to 5; very short answer type questions of 1 mark 
each. 
3. Section B contains questions number 6 to 10, short-answer type I questions of 2 marks 
each. 
4. Section C contains questions number 11 to 22, short answer type II questions of 3 marks 
each. 
5. Section D contains question number 23, value based question of 4 marks. 
6. Section E contains questions number 24 to 26, long-answer type questions of 5 marks 
each. 
7. There is no overall choice in the question paper; however, an internal choice is provided 
in one question of 2 marks, one question of 3 marks and all the three questions of 5 
marks. In these questions, an examinee is to attempt any of the two given alternatives. 
 
 
SECTION A 
 
1. What is a cistron? [1] 
 
2. How many chromosomes do drones of honeybee possess? Name the type of cell division 
involved in the production of sperms by them.  [1] 
 
3. List two advantages of the use of unleaded petrol in automobiles as fuel. [1] 
 
4. Retroviruses have no DNA. However, the DNA of the infected host cell does posses viral 
DNA. How is it possible? [1] 
 
5. Suggest any two possible treatments that can be given to a patient exhibiting adenosine 
deaminase deficiency. [1] 
 
 
 
 
 
 
  
 
CBSE XII  |  Biology 
Board Paper – 2015 – All India – Set 3 
 
     
 
SECTION B 
 
6. Select two pairs from the following which exhibit divergent evolution. Give reasons for 
your answer. [2] 
(i) Forelimbs of cheetah and mammals 
(ii) Flippers of dolphins and penguins 
(iii) Wings of butterflies and birds 
(iv) Forelimbs of whales and mammals 
 
7. A liverwort plant is unable to complete its life cycle in a dry environment. State two 
reasons. [2] 
 
8. What is mutualism? Mention any two examples where the organisms involved are 
commercially exploited in agriculture. 
OR 
List any four techniques where the principle of ex-situ conservation of biodiversity has 
been employed. [2] 
 
9.   [2] 
(a) Why are the plants raised through micropropagation termed as somaclones? 
(b) Mention two advantages of this technique. 
 
10. Explain the function of “anaerobic sludge digester” in a sewage treatment plant. [2] 
 
SECTION C 
 
11. The F 2 progeny of a monohybrid cross showed phenotypic and genotypic ratio as 1:2:1 
unlike that the Mendel’s monohybrid F 2 ratio. With the help of a suitable example, work out 
a cross and explain how it is possible. [3] 
 
12. Why are some seeds referred to as apomictic seeds? Mention one advantage and one 
disadvantage to a farmer who uses them. [3] 
 
13. A heavily bleeding and bruised road accident victim was brought to a nursing home. The 
doctor immediately gave him an injection to protect him against a deadly disease. 
(a) Write what did the doctor inject into the patient’s body 
(b) How do you think this injection would protect the patient against the disease? 
(c) Name the disease against which the injection was given and the kind of immunity it 
provides. [3] 
 
14. “A very small sample of tissue or even a drop of blood can help determine paternity”. 
Provide a scientific explanation to substantiate the statement. [3] 
  
 
CBSE XII  |  Biology 
Board Paper – 2015 – All India – Set 3 
 
     
 
 
15. What does the following equation represent? Explain. [3] 
p
2
 + 2pq + q
2
 = 1 
 
16. Describe any three potential applications of genetically modified plants. [3] 
 
17. How did an American company, Eli Lilly use the knowledge of r-DNA technology to produce 
human insulin? [3] 
 
18. How do snails, seeds, bears, zooplanktons, fungi and bacteria adapt to conditions 
unfavourable for their survival? [3] 
 
19. Enumerate any six essentials of good, effective dairy farm management practices. [3] 
 
20. With the help of flow chart, show the phenomenon of biomagnification of DDT in an aquatic 
food chain. [3] 
 
21. State the medicinal value and the bioactive molecules produced by Streptococcus, Monascus 
and Trichoderma.  [3] 
OR 
What are methanogens? How do they help to generate biogas? 
 
22. Rearrange the following in the correct sequence to accomplish an important 
biotechnological reaction:  [3] 
(a) In vitro synthesis of copies of DNA of interest 
(b) Chemically synthesized oligonucleotides 
(c) Enzyme DNA – polymerase 
(d) Complementary region of DNA 
(e) Genomic DNA template 
(f) Nucleotides provided 
(g) Primers 
(h) Thermostable DNA-polymerase (From Thermus aquaticus) 
(i) Denaturation of ds-DNA 
 
SECTION D 
 
23. Your school has been selected by the Department of Education to organize and host and 
interschool seminar on “Reproductive health – problems and practices”. However, many 
parents are reluctant to permit their wards to attend it. Their argument is that the topic is 
“too embarrassing”. 
Put fourth four arguments with appropriate reasons and explanation to justify the topic to 
be very essential and timely. [4] 
Page 4


  
 
CBSE XII  |  Biology 
Board Paper – 2015 – All India – Set 3 
 
     
 
CBSE 
Class XII Biology 
Board Paper 2015 – All India (Set 3) 
Time: 3 hrs Total Marks: 70 
 
General Instructions: 
1. There are total 26 questions and five sections in the question paper. All questions are 
compulsory. 
2. Section A contains questions number 1 to 5; very short answer type questions of 1 mark 
each. 
3. Section B contains questions number 6 to 10, short-answer type I questions of 2 marks 
each. 
4. Section C contains questions number 11 to 22, short answer type II questions of 3 marks 
each. 
5. Section D contains question number 23, value based question of 4 marks. 
6. Section E contains questions number 24 to 26, long-answer type questions of 5 marks 
each. 
7. There is no overall choice in the question paper; however, an internal choice is provided 
in one question of 2 marks, one question of 3 marks and all the three questions of 5 
marks. In these questions, an examinee is to attempt any of the two given alternatives. 
 
 
SECTION A 
 
1. What is a cistron? [1] 
 
2. How many chromosomes do drones of honeybee possess? Name the type of cell division 
involved in the production of sperms by them.  [1] 
 
3. List two advantages of the use of unleaded petrol in automobiles as fuel. [1] 
 
4. Retroviruses have no DNA. However, the DNA of the infected host cell does posses viral 
DNA. How is it possible? [1] 
 
5. Suggest any two possible treatments that can be given to a patient exhibiting adenosine 
deaminase deficiency. [1] 
 
 
 
 
 
 
  
 
CBSE XII  |  Biology 
Board Paper – 2015 – All India – Set 3 
 
     
 
SECTION B 
 
6. Select two pairs from the following which exhibit divergent evolution. Give reasons for 
your answer. [2] 
(i) Forelimbs of cheetah and mammals 
(ii) Flippers of dolphins and penguins 
(iii) Wings of butterflies and birds 
(iv) Forelimbs of whales and mammals 
 
7. A liverwort plant is unable to complete its life cycle in a dry environment. State two 
reasons. [2] 
 
8. What is mutualism? Mention any two examples where the organisms involved are 
commercially exploited in agriculture. 
OR 
List any four techniques where the principle of ex-situ conservation of biodiversity has 
been employed. [2] 
 
9.   [2] 
(a) Why are the plants raised through micropropagation termed as somaclones? 
(b) Mention two advantages of this technique. 
 
10. Explain the function of “anaerobic sludge digester” in a sewage treatment plant. [2] 
 
SECTION C 
 
11. The F 2 progeny of a monohybrid cross showed phenotypic and genotypic ratio as 1:2:1 
unlike that the Mendel’s monohybrid F 2 ratio. With the help of a suitable example, work out 
a cross and explain how it is possible. [3] 
 
12. Why are some seeds referred to as apomictic seeds? Mention one advantage and one 
disadvantage to a farmer who uses them. [3] 
 
13. A heavily bleeding and bruised road accident victim was brought to a nursing home. The 
doctor immediately gave him an injection to protect him against a deadly disease. 
(a) Write what did the doctor inject into the patient’s body 
(b) How do you think this injection would protect the patient against the disease? 
(c) Name the disease against which the injection was given and the kind of immunity it 
provides. [3] 
 
14. “A very small sample of tissue or even a drop of blood can help determine paternity”. 
Provide a scientific explanation to substantiate the statement. [3] 
  
 
CBSE XII  |  Biology 
Board Paper – 2015 – All India – Set 3 
 
     
 
 
15. What does the following equation represent? Explain. [3] 
p
2
 + 2pq + q
2
 = 1 
 
16. Describe any three potential applications of genetically modified plants. [3] 
 
17. How did an American company, Eli Lilly use the knowledge of r-DNA technology to produce 
human insulin? [3] 
 
18. How do snails, seeds, bears, zooplanktons, fungi and bacteria adapt to conditions 
unfavourable for their survival? [3] 
 
19. Enumerate any six essentials of good, effective dairy farm management practices. [3] 
 
20. With the help of flow chart, show the phenomenon of biomagnification of DDT in an aquatic 
food chain. [3] 
 
21. State the medicinal value and the bioactive molecules produced by Streptococcus, Monascus 
and Trichoderma.  [3] 
OR 
What are methanogens? How do they help to generate biogas? 
 
22. Rearrange the following in the correct sequence to accomplish an important 
biotechnological reaction:  [3] 
(a) In vitro synthesis of copies of DNA of interest 
(b) Chemically synthesized oligonucleotides 
(c) Enzyme DNA – polymerase 
(d) Complementary region of DNA 
(e) Genomic DNA template 
(f) Nucleotides provided 
(g) Primers 
(h) Thermostable DNA-polymerase (From Thermus aquaticus) 
(i) Denaturation of ds-DNA 
 
SECTION D 
 
23. Your school has been selected by the Department of Education to organize and host and 
interschool seminar on “Reproductive health – problems and practices”. However, many 
parents are reluctant to permit their wards to attend it. Their argument is that the topic is 
“too embarrassing”. 
Put fourth four arguments with appropriate reasons and explanation to justify the topic to 
be very essential and timely. [4] 
  
 
CBSE XII  |  Biology 
Board Paper – 2015 – All India – Set 3 
 
     
 
SECTION E 
24.   [5] 
(a) How are Mendelian inheritance, polygenic inheritance and pleiotropy different from 
each other? 
(b) Explain polygenic inheritance pattern with the help of a suitable example. 
OR 
(a) Draw a labelled diagram of a “replicating fork” showing the polarity. Why does DNA 
replication occur within such “forks”? 
(b) Name two enzymes involved in the process of DNA replication along with their 
properties. 
 
25.    [5] 
(a) List the different attributes that a population has and not an individual organism. 
(b) What is population density? Explain any three different ways the population density 
can be measured, with the help of an example each 
OR 
“It is often said that the pyramid of energy is always upright. On the other hand, the 
pyramid of biomass can be both upright and inverted”. Explain with the help of examples 
and sketches. 
 
26.    [5] 
(a) Plan an experiment and prepare a flow chart of the steps that you would follow to 
ensure that the seeds are formed only from the desired sets of pollen grains. Name the 
type of experiment that you carried out. 
(b) Write the importance of such experiments. 
OR 
Describe the roles of pituitary and ovarian hormones during the menstrual cycle in a 
human female.