Multiple Choice Questions

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Anemophillous flowers have :

  • sessile stigma

  • small and smooth stigma

  • coloured flower

  • large and feathery stigma


D.

large and feathery stigma

In anemophillous flowers, pollination is carried out by wind. The plants pollinated in this manner are grasses, which have insignificant unscented flowers with large, often feathery stigma.


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

  • oogenesis

  • sporogenesis

  • gametogenesis

  • spermatogenesis


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


Acid rain is due to increase in atmospheric concentration of :

  • Ozone

  • CO2 and CO

  • SO3 and CO

  • SO2 and nitrogen oxide


The first transgenic crop was :

  • pea

  • flax

  • tobacco

  • cotton


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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


Secretion of androgens by testes is regulated by:

  • LTH

  • FSH

  • ICSH

  • Oxytocin


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


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

  • apospory

  • apogamy

  • parthenogenesis

  • none of these


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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