Paper : CBSE Class 12th Biology Exam Paper, 2003 (Outside Delhi: Set-1)

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 choice 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. 1. A digestive juice with a pH of approximately 2 is found inside the
(a) Mouth
(b) Stomach
(c) pancreatic duct
(d) small intestine 1
Ans. (b)

 

Q. 2. What was the most significant conclusion that Mendel drew from his experiments? 1
(a) There is considerable genetic variation in garden pea
(b) Traits are inherited in discrete units, one from each parent
(c) Genes are composed of DNA
(d) Recessive genes occur as frequently as dominant ones
Ans. (d)

 

Q. 3. Which of the following is not a useful function of the light reactions in photosynthesis? 1
(a) Splitting water
(b) Synthesis of NADPU
(c) Converting light energy into chemical energy
(d) Releasing oxygen for photorespiration
Ans. (c)

 

Q. 4. In the flammatory response, the absence of which one of the following would prevent all the others from happening? 1
(a) Release of histamine
(b) Dilation of arterioles
(c) Increased population of phagocytes in the area
(d) Increased permeability of blood vessels
Ans. (a)

 

Q. 5. A biogeographical evidence in favour of organic evolution is provided by
(a) Archeopteryx
(b) Modern horse
(c) Darwin’s finches
(d) Python 1
Ans. (c)

 

Q. 6. Which type of immunity is provided by vaccinations? 1

 

Q. 7. Name the tissue involved in linear and lateral growth in plants. 1

 

Q. 8. Why are proteases generally released an inactive form? 1

SECTION - B

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

Q. 9. What is SA node? Where it located and what is its function? 2

 

Q. 10. What is reproductive isolation? What is its significance? 2

 

Q. 11. Give the scientific name of the pathogen causing Diphtheria. How is it transmitted? 2

 

Q. 13. Name the hormone responsible for the descent of testes into the scrotum. Why does the failure of the process result in sterility? 2

 

Q. 15. What is ELISA test? Give its full form. Give-two examples of its application 2

 

Q. 17. Explain inhibitory effect of auxins with the help of one example. 2

SECTION - C

Q. Nos. 19-2 7 are of short answer type carrying 3 marks each. Only one of these questions (Q. 27) based on drawing skill has internal choice. Answer the rest in 30-50 words each.

Q. 19. What is metastasis? List any four danger signals of cancer. 3

 

Q. 27. Draw a diagram of the human duodenum and the associated digestive glands. Label the glands and their respective ducts pouring into the duodenum. 3

Or

Draw a diagram to show the structure of a neuron with myelinated axon and label any six parts in it.

SECTION - D

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

Q. 29. Describe the hormonal control of menstrual cycle in humans.

Or

Where does oogenesis take place? Describe the stages of the process.