Multiple Choice Questions

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The production and maturation of sperm in testes is known as :

  • oogenesis

  • sporogenesis

  • gametogenesis

  • spermatogenesis


D.

spermatogenesis

The production and maturation of sperms in testes is known as spermatogenesis. It involves the successive formation of spermatogonia, primary spermatocytes, secondary spermatocytes, spermatids and spermatoza.


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During a woman's life time, she produces about:

  • 40-50 eggs

  • 300-350 eggs

  • 400-500 eggs

  • 750-850 eggs


The formation of gametophyte, from sporophyte, without spore formation or without meiosis is known as :

  • apospory

  • apogamy

  • parthenogenesis

  • none of these


Secretion of androgens by testes is regulated by:

  • LTH

  • FSH

  • ICSH

  • Oxytocin


Photochemical smog formed in congested metropolitan cities mainly consists of:

  • Hydrocarbons, ozone and SOx

  • Hydrocarbons, SO2 and CO2

  • Smoke, peroxyacetyl nitrate and SO2

  • Ozone, peroxyacetyl nitrate and NOx


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One of the major difficulties in the biological control of insect pests is the :

  • practical difficulty of introducing the predator to specific areas

  • method is less effective as compared with the use of insecticides

  • predator does not always survive when transferred to a new environment

  • predator develops a preference to other diets and may itself become a pest


Anemophillous flowers have :

  • sessile stigma

  • small and smooth stigma

  • coloured flower

  • large and feathery stigma


The first transgenic crop was :

  • pea

  • flax

  • tobacco

  • cotton


Acid rain is due to increase in atmospheric concentration of :

  • Ozone

  • CO2 and CO

  • SO3 and CO

  • SO2 and nitrogen oxide


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The true statement about 'green-house effect' is that it is caused by :

  • CO2 only

  • SO2 only

  • CO2 and SO2

  • CO2, CFC, CH4 and NO2 gases