Multiple Choice Questions

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If decomposers are removed what will happen to the ecosystem?

  • Energy cycle is stopped

  • Mineral cycle is stopped

  • Consumers cannot absorb solar energy

  • Rate of decompostion of mineral increases


B.

Mineral cycle is stopped

Decomposers are heterotropic organisms, mostly bacteria and fungi which live on dead organic matter or detritus. They release different enzymes from their bodies into the dead and decaying plant and animal remains. The extra cellular digestion of the dead remains, lead to the release of simple inorganic substances.


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Which of the following is used as green manure?

  • Azolla

  • Azadirachta

  • Crotolaria juncea

  • Hevea brassiliansis


Gases found in primitive atmosphere are

  • CH4, NH3, H2, H2O (vapour form)

  • CH4, NH3, CO2, H2O

  • CH4, H2O, CO2

  • CH4, O2, CO2


Nitrifying bacteria are able to

  • convert atmospheric nitrogen into soluble forms

  • convert ammonia to nitrate

  • ammonia to nitrogen

  • nitrate to nitrogen


Lichen is the pioneer vegetation on which succession?

  • Hydrosere

  • Lithosere

  • Psammosere

  • Xerosere


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The effect of intraspecific competition on niches is to make them

  • smaller

  • larger

  • change location

  • more triangular


The presence of diversity at the junction of territories of two different habitats is known as

  • bottleneck effect

  • edge effect

  • junction effect

  • Pasteur effect


Small fish get stuck near the bottom of a shark and derives its nutrition from it. This kind of association is called as

  • antibiosis

  • commensalism

  • predation

  • parasitism


the group of Anamniota includes

  • reptiles and birds

  • birds and mammals

  • fishes an amphibians

  • reptiles and mammals


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Green plants constitute

  •  first trophic level

  • second trophic level

  • third trophic level

  • complete food chain


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