CBSE Exam Results 2013

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CBSE Question Paper 2009 for Class 12 - Biology

by saumil shrivastava

General Instruction for CBSE Question Paper :

(i) All the question are compulsory.

(ii) This question paper consists of four sections A, B, C and D. Section A contains 8 question of one marks each, Section B is of 10 questions of two marks each. Section C is of 9 question of three marks each and section D is of three question of five marks each.

(iii) There is no overall choice. However, an internal chouice has been provided in one question of 2 marks, one question of 3 marks and all the three question of 5 marks weightage. A student has to attempt only one of the alternatives in such questions.

(iv) Wherever necessary, the diagrams drawn should be neat and properly labelled.

Section A

1. Why hnRNA is required to undergo splicing?

2. The microscope pollen grain of the past are obtained as fossils. Mention the characteristics of the pollen grains that makes it happen.

3. How does colostrum provide initial protection against diseases to new born infants? Give one reason.


Name the unlabelled areas 'a' and 'b' of the pie chart (Give above) representing the global biodiversity of invertebrates showing their proportionate number of species of major taxa.

5. Mention the type of evolution that has brought the similarity as seen in potato under and sweet potato.

6. Name the group of organisms and the substrate they act on to produce bio gas.

7. Mention the pollinating agent of an inflorescence of small dull coloured flowers with well exposed stamens and large feathery stigma. Give any one characteristics of pollen grains produced by such flowers.

8. Name the organism Commercially used for the production of single cell protein.

Section - B

9. Explain the contributed of Thermus aquaticus in the amplification of gene of interest.


(i) What does the above diagram illustrate
(ii) Name the parts labelled 'a' and 'b'
(iii) Name the type of cells that produce this module.

11. Banana is a parthenocarpic fruits whereas Oranges show ployembryony. How are they different from each other with respect to seeds


Where are fimbriae present in a human female reproductive system? Give their function.

12. How is the translation of mRNA terminated? Explain.

13. Explain accelerated eutrophication. Mention any two consequences of this phenomenon.

14. List the specific symptoms of amoebiasis. Name the causative organism.

15. A crane had DDT level as 5 ppm in its body. what would happen to the population of such birds? Explain giving reasons.

16. Describe the responsibility of GEAC, set up by the Indian Government.

17. During the secondary treatment of the primary effluent how does the significant decrease in BOD occur?

18. Study the figure given below and answer the questions:

(i) How does the repressor molecule get inactivated?
(ii) When does the transcription of lac mRNA stop?
(iii) Name the enzyme transcribed by the gene 'Z'

Section C

19. Name the pioneer species on a bare rock. How do they help in establishing the next type of vegetation? Mention the type of climax community that will ultimately get established.

20. Study the figures given below and answer the question that follow:

A. Name the stages of human embryo the figure represents.
B. Identify 'a' in the figures and mention its function.
C. Mention the fate of the inner cell mass after implantation in the uterus.
D. Where are the stem cells located in this embroy?

21. Give the Scientific name of the parasite that cause malignant malaria in humans. At what stages does this parasite enter the human body? Trace its life cycle in human body.

22. Draw a labelled schematic sketch of replication fork of DNA. Explain the role of the enzymes involved in DNA replication.

23. Explain the causes of global warming. Why is it a warning to mankind?

24. Haemophilia is a sex linked recessive disorder of humans. The pedigree chart given below shows the inheritance of haemophilia in one family. study the pattern of inheritance and answer the question given.

A. Give all the possible genotypes of the member 4, 5 and 6 in the pedigree chart.

B. A blood test shows that the individual 14 is carrier of haemophilia. The member numbered 15 has recently married the member numbered 14. What is the probability that their first child will be a haemophilic male?


Inheritance pattern of ABO blood groups in humans shows dominance, codominance and multiple allelism. Explain each concept with the help pf blood group genotype


A. Mention the specific geographical region where these organism are found.
B. Name and explain the phenomenon that has resulted in the evolution of such diverse species in the region.
C. Explain giving reasons the existence of placement Wolf and Tasmanian Wolf Sharing the same habitat.


A. Identify the selectable markers in the diagram of E.coli vector shown above.
B. How is the coding of  \alpha - galactosidase considered a better marker than the ones identification by you in the diagram? Explain.

27. Construct an ideal pyramid of energy when 1,000,000 joules of Sunlight is available. Label all its trophic levels.

28. Explain with the help of a diagram the development of a mature embryo sac from a megaspore mother cell in angiosperm.


Study the following flow chart. Name the hormones involved at each stages. Explain their functions.

29. A. Explain the experiment performed by Griffith on Streptococcus pneumoniae. What did he conclude from this experiment?

B. Name the three scientific who followed up Griffith's experiments.
C. What did they conclude and how?


Two blood samples A and B picked up from the crime scene were handed over to the forensic department for genetic fingerprinting. Describe how the technique of genetic fingerprinting is carried out. How will be confirmed whether the sample belonged to the same individuals or two different individuals?

30. One of the main objectives of biotechnology is to minimize the use of insecticide on the cultivation crops. Explain with the help of a suitable example how insect resistant crops have been developed using techniques of biotechnology.


A. How is mature insulin different from proinsulin secreted by pancreas in human?
B. Explain how was human functional insulin produced using rDNA technology.
C. Why id the functional insulin thus produced considered better than one used earlier by diabetic patients?

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    sakshichaudharyWed, 11 Sep 2013 10:23:50 -0000

    Thanks for providing the giving sample papers. They helped me to prepare in a better way. If you are willing to get CBSE Sample papers than Visit Solved CBSE Sample Papers for Class 12 Biology

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    h blue
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    h blueFri, 22 Jun 2012 03:21:59 -0000

    a perfect bio sample paper…..evry one mst read read it……questions r awesome…n… top levelevd,,,,,

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    raja babu
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    raja babuSun, 13 Mar 2011 16:02:17 -0000

    cbse should make easy paper of all subject and check paper with loose marking

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