CSIR NET JRF: Zoology MCQs (Practice-Test 6 of 112)

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1. Which one of the following pairs of substances and functions is NOT correctly matched?

   1. • Actin
      • Slides past myosin causing contraction
   2. • Calcium
      • Triggers enzymatic action of myosin
   3. • ATPase
      • Enzyme that splits ATP
   4. • ATP
      • Supplies energy for breaking actomyosin

2. Which one of the following sets of organisms develops Parthenogenetically?

   1. Aphids, bees and grasshoppers

   2. Bees, wasps and ants

   3. Ants, Aphids and earthworms

   4. Wasps, cockroaches and fish

3. The fertilization cone that pulls the sperms into the egg is formed from the

   1. acrosome of the sperm

   2. acrosomal process

   3. vitelline layers of the egg

   4. plasma membrane of the egg

4. The correct sequence of gastrulation in frog is

   1. Involution and epiboly

   2. Invagination, involution and epiboly

   3. Invagination and convergence

   4. Convergence, involution and ingression

5. In the embryonic development of frog, the animal pole forms

   1. head

   2. tail

   3. dorsal side

   4. ventral side

6. Which one of the following is a vital dye used to observe the embyonic cell movement during gastnulation?

   1. Janus green

   2. Toluidine blue

   3. Eosin

   4. Alcian blue

7. The part of chick embryo comparable to the dorsal tip of amphibian blastopore is the

   1. primitive streak

   2. primitive groove

   3. anterior margin of Hansen's node

   4. area pellucida

8. Match List (Cleavage type) with List II (Exam/feature) and select the correct answer:

   List-I	List-II
   Meroblastic Holoblastic Spiral Bilateral	Dextral Germinal disc Telolecithal Mesolecithal

   • A
   • B
   • C
   • D
   1. • 2
      • 4
      • 3
      • 1
   2. • 4
      • 2
      • 1
      • 3
   3. • 4
      • 2
      • 3
      • 1
   4. • 2
      • 4
      • 1
      • 3

9. Which one of the following cell organelles participates in the construction of daughter blastomeres during cleavage?

   1. Microtuu1es

   2. Microfilaments

   3. Microsomes

   4. Micromeres

10. Extraembryonic membranes provide protection and secure food for the developing embryo in amniotes. What is the significance of vestigial yolk sac in mammals?

    1. Adaptive

    2. Evolutionary

    3. Protective

    4. Synthetic

11. Primordial atmosphere of the earth could NOT possibly have combined

    1. nitrogen

    2. oxygen

    3. hydrogen

    4. methane

12. Modem synthetic theory of evolution has emerged as a result of the studies on

    1. population dynamics

    2. gene recombination

    3. hybridization between species

    4. population isolation

13. The correct sequence of evolution leading to present-day horses is

    1. Eohippus, Miohippus, Merychippus, Pliohippus, Equus

    2. Eohippus, Pliohippus, Merychippus, Orhippus, Equus

    3. Eohippus, Mesohippus, Orhippus, Merychippus, Pliohippus. Equus

    4. Eohippus, Merychippus, Miohippus

    Orhippus, Equus

14. Which one of the following correctly defines point mutation?

    1. Changes in the location of a block of genes in the chromosomes

    2. Inversion of a block of genes within a chromosome

    3. Loss of a segment of DNA containing one or several genes from a chromosome

    4. Alteration in the DNA sequence of a gene and passing of the new nucleotide sequence to the offspring

15. Which one of the following statements is NOT correct regarding mutation?

    1. Mutations are changes either in the genes or in the chromosomes

    2. Mutations may be dominant or recessive

    3. Mutations are always recessive

    4. Recessive gene mutations may remain dormant for generations