CBSE Guess > Papers > Question Papers > Class XII > 2005 > Biology > Outside Delhi Set-III

BIOLOGY 2005 (Set III—Outside Delhi)

Except for the following questions all the remaining questions have been asked in Set I & Set II.

SECI1ON - A

Q. 1. Why does thinning of bones usually start occurring in human females at about 50 years of age? 1

Q. 2. Drosera carries out photosynthesis and still traps insects. Why? 1

Q. 3. What causes Gouty Arthritis in humans? 1

Q. 4. List two factors that determine the vegetation and soil type of an ecosystem. 1

Q. 5. Why is gene encoding for “Cry” protein inserted into a crop plant? 1
SECTION - B

Q. 6. What is multiplicative growth? How is it different from auxetic growth? 2

Q. 7. What is the source of explants in a meristem culture? Mention one function of cytokinins used in the meristem culture medium. 2

Q. 9. What is biogas ‘Give its composition. Why is biogas preferred to other conventional energy fuels? 2

Q. 10. An Rh-negative mother has safely delivered her first Rh-positive child. Discuss the problems that can arise as a result of it and can affect a subsequent pregnancy. 2

Q. 12. What is oxidative decarboxylation? What happens to pyruvate immediately after this reaction? Name the enzyme involved in this reaction. 2

Q. 13. What is the end product of glycolysis in aerobes, and where does this process occur? List the conditions under which fermentation occurs in plant cells. 2
Or
Where exactly does electron transport system operate in Mitochondria? What is the role of oxygen and F0 — F1 in this pathway? How may molecules of ATP are produced when one molecule of NADH goes through this path?

Q. 14. Name the causal organism of tick fever in animals. Give two symptoms of the disease in acute form. Name the body cells the pathogen attacks. 2

Q. 15. List any two functions of thyroid gland in humans. Name the condition caused due to Hyperthyroidism and give its one symptom. 2

Q. 17. In what form in Magnesium absorbed by plants from the soil ? Give two functions of Magnesium in plants and its two deficiency symptoms. 3

Q. 24. What is the ecological succession of bare rock technically called? Name the first and the last-but-one succession stages in it. Explain how the climax community gets established in this succession. 3
SECTION - D

Q. 27. What is cardiac cycle? Explain the different steps involved in the pumping action of the heart during a single cardiac cycle. 5
Or
a) What is residual volume? How much is it in a normal human adult?
b) Explain the role of diaphragm and ribcage in Inspiration and expiration in humans.