Previous Solved GATE Life Science Questions - Zoology

Previous Question Papers
1. Hemolin is
(a) An antibody produced by sponges
(b) An antibody produced by Annelids
(c) A member of the immunoglobulin superfamily
(d) A cytotoxic molecule produced by nematodes
Ans: Hemolin is a bacteria-inducible hemolymph protein of the giant silk moth Hyalophora cecropia. Hemolin belongs to the immunoglobulin superfamily
2. Most modern taxonomists group living organisms into how many kingdoms?
(a) 2
(b) 4
(c) 3
(d) 5
Ans: 5 kingdom by Whittaker 1969 based on three criteria
  • complexity of cell structure
  • complexity of organism body
  • mode of obtaining nutrition
3. Acrosome present on the sperm head is derived from
(a) Golgi apparatus
(b) Nucleus
(c) Centrosome
(d) Endoplasmic reticulum
Ans: Golgi apparatus
  • The golgi body is modified to form a sheath called acrosome on the first part of the head
4. Which of the following non-covalent interactions is considered as strongest?
(a) Hydrophobic interactions
(b) Ionic bonds
(c) Hydrogen bonds
(d) Vander waals forces
Ans: Hydrogen bonds
5. Sickle-cell anemia is caused by mutation in
(a) Haemoglobin A
(b) Haemoglobin B
(c) Haemoglobin S
(d) Haemoglobin F
Ans: Haemoglobin A
  • Molecular basis for this disease: change of glutamic acid residue for a valine (non conservative substitution reaction).
  • Normal Hb: Hb A (adult)
  • Sickle cell Hb: Hb S
6. Life appeared on earth
a) 5000 million years ago
b) 3500 million years ago
c) 1000 million years ago
d) 500 million years ago
Ans: b) 3500 million years ago
For more, refer our post: Geological Time Scale
7. The sub cellular organelle not bound by a single membrane is
a) Golgi apparatus
b) Endoplasmic Reticulam (ER)
c) Mitochondria
d) Lysosomes
Ans: Mitochondria
  • Double membrane organelle (Nucleus, Chloroplast, Mitochondria)
8. The storage carbohydrate in animal is
a) Starch
b) Cellulose
c) Glycogen
d) Glucose
Ans: Glycogen
  • Starch: storage carbohydrate in plants
  • Cellulose: structural polysaccharide in the plant cell wall
  • Glucose: primary energy source
More about: Carbohydrates
9. The hormone testosterone is produced by
a) Leydig cells
b) Spermatocyte
c) Melanocytes
d) β cells of Pancreas
Ans: a) Leydig cells
10. The predominant antibody in saliva is
a) IgG
b) IgM
c) IgA
d) IgD
Ans: c) IgA
  • IgG: Most abundant immunoglobulin, produce in the late primary response after IgM production, predominant in secondary immune response, the one and only Ig that cross placenta.
  • IgA: Secretory antibody, Heaviest antibody and second most abundant
  • IgM: Macroimmunoglobulin, pentamer, does not cross placenta, also known as natural antibody, first produced antibody upon infection.
  • IgD: Present on surface of B-cells and in serum.
  • IgE: which is responsible for allergic reactions, mediate hyper sensitivity. These are concentrated in mucous membrane, skin and lungs.


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