ZOOLOGY (2020 SAY)
ANSWERS
1. (c) Thorns and tendrils of Bougainvillea and Cucurbita
2. (b) Morula
3. (c) Birds
4. (b) Azospirillum
5. (c) AUG
6. (a) Typhoid.
(b) Salmonella typhi.
(c) Sustained high fever, stomach
pain, constipation, head ache etc.
7. a. Vas deferens
b. Epididymis
c. Urethra
d. Testis
8. (a) Allele frequencies in a population are stable and is
constant from generation to generation.
(b) Gene migration, Genetic
drift, Mutation etc.
9. (a) 44A + XXY
(b) Turner’s syndrome
(c) Sterile female/ ovaries
are rudimentary etc.
(d) Down’s syndrome
10. Match the following:
|
(a) Acetic acid (b) Citric acid (c) Cyclosporine A (d) Lactic acid |
(ii) Acetobacter aceti (iv) Aspergillus niger (i) Trichoderma polysporum (iii) Lactobacillus |
11. Gametogenesis → Insemination → Fertilisation → Formation of
Zygote → Implantation → Gestation → Parturition → Lactation
12. (a) Incomplete dominance
(b) Flower colour in Snap
dragon
(c) Phenotypic ratio =
1:2:1
Genotypic ratio = 1:2:1.
13.
I. a. Stabilizing selection.
b. Directional selection.
c. Disruptive selection.
II. The peak is shifted to one direction. i.e., more individuals
acquire value other than the mean character value.
14. (a) (i) Digestion of DNA
by restriction endonuclease.
(ii) Hybridisation using
labelled VNTR probe.
(b) Alec Jeffreys
(c) Variable Number of
Tandem Repeats.
15. (a) a. Promoter. b. Structural genes. c. Terminator.
(b) Exons
16. (a) Assisted Reproductive Technologies.
(b) i. Artificial insemination (AI) /
Intra-Uterine insemination (IUI). Ii. Gamete Intra fallopian Transfer (GIFT).
17. (a) Edward Wilson.
(b) In situ
conservation and Ex situ conservation.
(c) Habitat loss &
Fragmentation, Overexploitation, Alien species invasion etc.
18. (a) A. Vasectomy B.
Tubectomy
(b) Vasectomy: A
small part of the vas deferens is removed or tied up through a small incision
on scrotum.
Tubectomy: A small part of the
fallopian tube is removed or tied up through a small incision in the abdomen or
through vagina.
(c) To prevent any more
pregnancies.
19. (a) Promoter.
(b)
(c) z: β-galactosidase, y:
Permease, a: Transacetylase.
20. Avoid undue peer pressure.
Education and counselling.
Seeking help from parents
and peers.
Looking for danger signs.
Seeking professional and medical help.