Sunday, October 25, 2020

2019 March | HSE +2 Exam | Zoology - Answers

PART -B: ZOOLOGY 
ANSWERS 

1. Zoological parks.

2. Colostrum.

3.

4. Dryopithecus → Ramapithecus → Australopithecines → Homo habilis → Homo erectus → Neanderthal man → Homo sapiens

5. (a) Nucleosome.
    (b) 8
    (c) Euchromatin: Loosely packed, light stained and transcriptionally active region of chromatin.
         Heterochromatin: Densely packed, dark stained and inactive region of chromatin.

6. Homologous organs:
a. Forelimb of Man, Cheetah, Whale, Bat.
b. Thorns and tendrils of Bougainvillea and Cucurbita.
c. Vertebrate hearts or brains.

Analogous organs:
a. Wings of Butterfly, Bird.
b. Eye of the Octopus and Mammals.
c. Flippers of Penguins and Dolphins.

7. Yes. Because male can produce two types of gametes (sperms) – one with X chromosome and other with Y chromosome. Y chromosome is responsible for the male sex of the baby. Female can produce only gametes (Egg) containing X chromosome. X chromosome is responsible for female sex of the baby.

8. Phenylketonuria. Because it is a Mendelian disorder. Others are chromosomal disorders.

9. A= Endometrium / Uterus
    B= Ovary
    C= Isthmus of fallopian tube
    D= Ampulla of fallopian tube

10.  ⬩ Saccharomyces cerevisiae.
       
⬩ Lactobacillus. 
       ⬩ Trichoderma polysporum. 
       ⬩ Rhizobium.

11. (a) Acquired immunity.
      (b) Physiological barrier
      (c) Cytokine barrier
      (d) Cell mediated immunity.

12. 
⬩ Saheli 
      ⬩ Tubectomy (sterilization technique)
      ⬩ Nausea, abdominal pain, breakthrough bleeding etc.

13. The Evil Quartet:

a. Habitat loss and fragmentation.
b. Overexploitation.
c. Alien species invasion.
d. Co-extinction.

14.

Bacteria

Fungus

Virus

Protozoan

Typhoid

Pneumonia

Ringworms

Common cold

Malaria

Amoebiasis


15. 
  1. Chain B.
  2. Sickle cell anaemia.
  3. This is due to the single base substitution at the sixth codon of the β-globin gene from GAG to GUG.
  4. The mutant Hb molecule undergoes polymerization under low oxygen tension causing the change in shape of the RBC from biconcave disc to elongated sickle like structure.
16. 
  1. Suspect II may be responsible for the crime. Because DNA from crime scene matches with DNA of suspect II.
  2. A DNA sequence which is tandemly repeated in many copy numbers is called variable number tandem repeats (VNTR).
  3. Alec Jeffreys.
17. 
  1. Sexually Transmitted Diseases.
  2. Gonorrhoea, syphilis, genital herpes, chlamydiasis etc.
  3. Avoid sex with unknown partners/multiple partners. Always use condoms during coitus. 
18. (a) Transcription (RNA synthesis)
      (b) RNA polymerase.
      (c) Initiation: RNA polymerase binds at the promoter site of DNA.
Elongation: RNA chain is synthesized in 5’-3’ direction.
Termination: A termination factor (ρ factor) binds to the RNA polymerase and terminates the transcription.

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