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CBSE Guess > Papers > Question Papers > Class XII > 2006 > Biology > Compartment Outside Delhi Set -II

BIOLOGY— 2006 (Set II—Compartment Outside Delhi)

General instructions: See in the Set—I, Delhi Board, (Comptt.), 2006.


Q.1. What is meant by saying that the energy flow in an ecosystem is unidirectional.

Q.2. What is meant by carrying capacity of the environment (1)

Q. 3. How do red muscles differ from white muscles in regard to the number of mitochondria they contain?

Q. 4. Name the site for haematopoiesis in humans.

Q. 5. Name the types of cross pollination in silk cotton tree and Vallisneria respectively (1)


Q. 6. What is epinasty? Name the plant hormone responsible for it. (2)

Q. 7. What is primary productivity? How is it different from net primary productivity? (2)

Q. 8. List any four factors which may lead to loss of biodiversity. (2)


What is carbon dioxide fertilization effect? Describe its any one advantage to the plants.

Q. 9. What is inbreeding depression? Why do the self-pollinated crops not show the ill-effects of inbreeding depression? (2)

Q. 10. How are spontaneous mutations useful in nature? List any three types of changes in the nuclear material that lead to mutation (2)

Q. 11. What is the condition required for reverse osmosis to occur? Give one commercial use of this type of osmosis. (2)

Q. 12. Explain the role of potassium chloride and malate ions in stomata! opening (2)

Q.13. Mucus secreted by the goblet cells is of great significance in the stomach during the process of digestion. Give two reasons for this significance. (2)

Q. 14. Name the hormones stored in the posterior pituitary gland. Where are these hormones actually produced? (2)

Q. 15. Write two differences between parthenogenesis and parthenocarpy in plants. (2)


Q.16. Name the three basic types of cellular growth in the organisms Explain each of them briefly. (3)

Q. 17. Give one factor responsible for causing thermal stratification in a deep lake. Why during autumn and spring is a bloom of phytoplankton growth observed? (3)

Q. 18. Describe how the population of fish-eating birds living on the banks of a lake, where DDT is regularly sprayed to check mosquito growth for many years, would differ from that living on the banks of another lake which is free from such insecticide. Name the phenomenon involved. (3)

Q.19. Mention three features of cancer cells which distinguish them from normal cells (3)

Q. 20. Write the full name of the diagnostic technique MRI. Explain the principle on which this technique is based. (3)

Q.21. Identify two factors which make root nodules of leguminous plants a suitable site for N, fixation Mention their role in nitrogen fixation (3)

Q 22 What is Respiratoiy Quotient (RQ) what will be the RQ when carbohydrates and fats are used respectively as substrates in aerobic respiration? Give reason for the difference in the values. (3)


Why does Crassulacean Acid Metabolism pathway occur only in plants growing in dry conditions 9 Explain the steps involved in this pathway

Q. 23. Where and how does the exchange of respiratory gases take place in earthworm? Explain. (3)

Q. 24. Draw a labelled diagram of the neural chemical synapse showing the transmission of the nerve impulse across it. (3)

Q.25. Briefly describe the stages of spermatogenesis in humans. (3)


Q. 26. Give three reasons to explain why sustainable agriculture is considered to be environment-friendly. Mention briefly any two ways how biotechnology can contribute to sustainable agriculture. (5)


  1. Name the two types of lymphocytes involved in the specific immune system.
  2. Mention the two types of specific immunity they generate.
  3. Why is specific immunity considered to be unique in its function? Write any three special features of it.

Q. 27. Write any four differences between non-cyclic and cyclic photophosphorylation. Do they both occur simultaneously in the chioroplast? Explain. (5)


Explain C pathway of photosynthesis. Why is it called so?

Q. 28. What is a cardiac cycle ? Explain the pumping action of heart during a cardiac cycle. (5)


Where exactly is the cardiac impulse generated in the human heart? Give one reason for generation of the action potential in this part of the heart Explain briefly how the action potential travels to auricles and ventricles.

Biology 2006 Question Papers Class XII
Delhi Outside Delhi Compartment Delhi Compartment Outside Delhi
Indian Colleges Set I Indian Colleges Set I Indian Colleges Set I Indian Colleges Set I
Indian Colleges Set II Indian Colleges Set II Indian Colleges Set II Indian Colleges Set II
Indian Colleges Set III Indian Colleges Set III Indian Colleges Set III