2020 SAY (+2)
PART A: ZOOLOGY
Answer any 3 questions from 1 - 5. Each carries 1 score. (3 x 1 = 3)
1. Which among the following is an example for homology?
(a) The eye of the Octopus and of Mammals
(b) Sweet potato and potato
(c) Thorns and tendrils of Bougainvillea and Cucurbita
(d) Wings of butterfly and of birds
2. The embryo with 8 to 16 blastomeres is called a ....................
3. Select a female heterogametic animal from the following:
(a) Human beings
4. A free living nitrogen fixing bacteria in the soil.
5. Find out the initiator codon among the following:
Answer any 9 questions from 6 – 16. Each carries 2 scores. (9 2 = 18)
6. Observe the list of certain common diseases in human given below and answer the following:
Common cold, Malaria, Amoebiasis, Typhoid, Filariasis
(a) Identify the bacterial disease among the enlisted.
(b) Name its causative organism.
(c) Mention any two symptoms of it.
8. (a) Define Hardy – Weinberg principle.
(b) List out any two factors affecting Hardy – Weinberg Equilibrium.
9. Complete the table using appropriate terms:
44A + XO
10. Match the following:
11. Rearrange the following human reproductive events in the correct order of their occurrence:
Lactation → Formation of Zygote → Insemination → Implantation → Fertilisation → Gametogenesis → Gestation → Parturition
12. In a cross between a true breeding red flowered and a true breeding white flowered plants, the F1 generation was pink coloured flowers. From this cross
(a) Identify the Inheritance.
(b) Give an example for this type of Inheritance.
(c) Write the F2 phenotypic and genotypic ratio.
13. Diagrammatic representation of the operation of natural selection on different traits is shown below:
I. Identify ‘a’, ‘b’ and ‘c’.
II. What is the evolutionary significance of ‘b’?
14. (a) Complete the flow chart given below showing DNA finger-printing technique.
(b) Who developed the DNA finger-printing technique?
(c) Write the full form of VNTR.
15. Schematic structure of a transcription unit is given below:
(a) Identify a, b and c.
(b) The coding sequences/expressed sequences in eukaryotes are known as ...................
16. (a) Expand ART.
(b) Suggest the ART which may be successful in the following condition:
(i) Inability of the male partner to inseminate the female.
(ii) Female cannot produce ovum but can provide suitable environment for fertilisation and further development.
III. Answer any 3 questions from 17 – 20. Each carries 3 scores. (3 x 3 = 9)
17. (a) The term ‘biodiversity’ was popularised by .................
(b) Name the two types of biodiversity conservation.
(c) Write any three causes of biodiversity loss.
18. Observe the diagrams A and B given below related to contraceptive methods.
(a) Identify A and B.
(b) Explain this surgical method.
(c) Why this method is generally advised as a terminal method of contraception?
19. Lactose catabolism in the absence of inducer in E. Coli is given below:
(a) Identify ‘P’.
(b) Draw the diagram in the presence of inducer.
(c) Write the enzymes produced by the structural genes ‘z’, ‘y’ and ‘a’.
20. Prepare a pamphlet as part of an awareness programme in your school regarding the “Prevention and control of Alcohol and Drug abuse in adolescents”.
[Hint: Prevention and control measures]