Paper : CBSE Class 12th Biology Exam Paper, 2003 (Outside Delhi: Set-2)

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

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 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. 1. Which one of the following is homologous to the wing of a bat? 1
(a) Tail of a kangaroo
(b) Wing of a butterfly
(c) Tail fin of a fish
(d) Arm of a human
Ans. (d)

 

Q. 3. Which of the following is an example of codominance? 1
(a) Pink flowers of snapdragon
(b) The ABO blood groups in humans
(c) Sex-linkage in humans
(d) Skin pigmentation in humans
Ans. (a)

 

Q. 4. What is the substrate of salivary amylase? 1
(a) Protein
(b) Starch
(c) Glucose
(d) Maltose
Ans. (b)

SECTION - B

Q. Nos. 9-18 are of short answer type carrying 2 marks each. Answer them in 29-30 words each.

Q. 9. What category of pathogens causes poliomyelitis? Mention the specific site of damage in the body, caused by this pathogen. How can this disease be prevented? 2

 

Q. 10. What happens to the walls of distal convoluted tuble (DCT) of a nephron when vasopressin is released by pituitary into the bloodstream? 2

 

Q. 18. How is fat digested in the humans? 2

SECTION - C

Q. Nos. 19-27are of short answer type carrying 3 marks each. Only one of these’ questions (Q. 27) based on & skill has internal choice. Answer the rest in approximately 30-50 words each.

Q. 19. What are the two striking observations that can be made in the comparative study of the early embryonic stages of the different classes of vertebrates? How does this study support the theory of organic evolution? 3

 

Q. 20. Name and describe a technique by which genetic disorder in the developing foetus can be detected.3