(Paper) CBSE Class 12th Biology Exam Paper, 2003 (Delhi: Set-3)

Paper : CBSE Class 12th Biology Exam Paper, 2003 (Delhi: Set-3)

Note: Except for the following questions, all the remaining questions have been asked in Set I and Set II

SECTION - A

Q. Nos. 1-8 are of very short answer type carrying 1 mark each. Of these the first five questions are of multiple choke type which have to be answered simply as A, B,C or D The remaining questions have to be answered in approximately 1-20 words each.

Q. 3. Most digestion occurs in 1
(a) Mouth
(b) Stomach
(c) Small intestine
(d) Large intestine
Ans. (c)

 

Q. 4. White eyes in male fruit flies is determined by a 1
(a) dominant gene on X
(b) recessive gene on Y
(c) dominant gene on Y
(d) recessive gene on X

 

Q. 7. Name the infectious disease that leads to wasting of human parts. 1


SECTION - B

Q. Nos. 9-18 are of short answer type carrying 2 marks each. Answer them in approximately 20-30 words each.

Q. 10. What structure forms the ‘corpus luteum’ and at what stage? Name two hormones secreted by it. 2

 

Q. 11. Explain how an XXY individual can be born in humans. 2

 

Q. 13. How do you consider tendrils of cucumber and thorns of Bougainvillea as homologous structures? 2


SECTION - D

Q. Nos. 28-30 are long answer type carrying 5 marks each. Of these two questions Q. 29 and 30 have internal choice. Answer the questions in approximately 80-120 words each.

Q. 28. (1) What is the significance of photolysis of water in photophosphorylation? What happens to each product of this process?
(ii) How does RuBP carboxylase act both as a carboxylase and as an oxygenase? Explain. 5

 

Q. 30. What is cardiac cycle? Describe the events that occur during joint diastole an atrial systole. 5


Or
List the different groups of hormones secreted by adrenal cortex. Give specific region of secretion and one major function of each Name the disorder that may occur in a human if the adrenal cortex is destroyed.