SECTION - A

1. Which factor stimulates the secondary oocyte to complete
   the suspended second meiotic division in humans?


2. Mention the role of ethidium bromide (EtBr) during agarose
   gel electrophoresis of DNA.


3. A person suffering from cancer is being treated using
   a-interferons. Give reason.


4. Why are statins used as blood-cholesterol lowering agents?


5. What is the use of polyblend which is prepared from
   modified plastic waste?
   SECTION - B


6. In an aquatic food chain amount of DDT in water is 0.
   ppb. What will be its probable amount in fish eating birds?
   Give reason.


7. Why is the mechanism of obtaining parthenocarpic fruits
   becoming important these days?


8. (a) If the distance between genes A and B is 3 map units,
   between genes B and C is 2 map units, between genes A
   and D is 5 map units and between genes C and D is 10 map
   units, find out the order of genes on a linkage map.
   (b) Why is RNA less suitable as a genetic material than DNA.
   Give reason.


9. Secondary immune response is more accelerated and
   intense than the primary immune response. Justify.

OR

How is mycorrihzal association beneficial to the plant?

10. How does human body compensate low oxygen availability
    at high altitudes?
    SECTION - C


11. (a) Why are pollen grains of angiosperms well preserved as
    microfossils?
    (b) What is the significance of corpus luteum?


12. Explain the experiment performed by Miller (1953) to
    provide an evidence for the abiogenic molecular evolution
    of life.


13. (a) What are the symptoms of common cold and its mode
    of infection?
    (b) Name the drugs used to reduce the symptoms of allergy.


14. Refer to the given figure showing stages of spermatogenesis
    and answer the accompanying questions.

GENERAL INSTRUCTIONS

(i) All questions are compulsory.

(ii) This question paper consists of five Sections A, B, C, D and E. Section A contains 5 questions of one mark each. Section B contains

5 questions of two marks each, Section C contains 12 questions of three marks each. Section D contains 1 question of VBQ type with

four marks and Section E contains 3 questions of five marks each.

(iii) There is no overall choice. However, an internal choice has been provided in one question of 2 marks, one question of 3 marks and all the

three questions of 5 marks weightage. A student has to attempt only one of the alternatives in such questions.

(iv) Wherever necessary, the diagrams drawn should be neat and properly labelled.

BOARD

CB SE

PRACTICE PAPER 2016

21 stMarch

Exam on

Time Allowed : 3 hours Maximum Marks : 70