Biology Question Paper2007

Sample Paper – 2007
Class – XII
Science (CBSE) Biology

Instructions
All questions are compulsory.
Section A has five questions of 1 mark each. Word limit is 10 words.
Section B has ten questions of 2 marks each. Word limit is 30 words.
Section C has ten questions of 3 marks each. Word limit is 50 words.
Section D has ten questions of 5 marks each. Word limit is 70 words.

SECTION A

1. What is sporopollenin?

2. Define ecotone.

3. What is threshold stimulus?

4. Which bacterium produces crystal protein?

5. What is corpus luteum?


SECTION B

OR

What is meant by long day plants? Give example.

11. What are hallucinogens? Give any one example.

12. What is CT scan used for? Who developed it?

13. Discuss apomixis and morphollaxis.

14. a.)Write names of all layers of atmosphere.
b.) Where is ozone layer?

15. Describe BOD and COD. Which one, BOD or COD is more?


SECTION C


16. Explain the process of formation of root nodules in legumes.

17. How is osmoregulation carried out in marine and fresh water fishes?

18. Describe anatomy of human gut?

19. Draw a well labeled diagram of retina and label any six parts.

OR

Draw a well labeled diagram of human ear and label any four parts.

20. Differentiate between mimicry and camouflage.

21. With the help of diagram describe the types of synapses.

22. Describe the process of spermatogenesis.

23. a.) Describe the transport of carbon dioxide in the blood.
b.) What is chloride shift?

24. Name any three plant hormones and their functions.

25. Explain the phenomenon of biological magnification.


SECTION D


26. Explain Calvin cycle.
OR
Where does E.T.S. take place? Explain the system and highlight the role of oxygen.

27. Briefly explain sliding filament theory of muscle contraction.
OR
Describe the hormonal control of reproductive system in human male
.
28. Explain the two routes of regenerating plantlets from callus culture.
OR
Describe adaptive immunity. Write any three disorders of immune system with symptoms.


6. Differentiate between apoplastic and symplastic pathway.

7. Explain the meaning of haemocoel.

8. Write short note on hypertension.

9. Explain any one sedimentary cycle.

10. Explain entomophilly and ornithophily with example.