Multiple Choice Questions

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Which of the following is used as green manure?

  • Azolla

  • Azadirachta

  • Crotolaria juncea

  • Hevea brassiliansis


C.

Crotolaria juncea

Crotolaria juncea, ia a common name of sunn hemp. It is a quick growing crop. It is cultivated and ploughed under to incorporate it into the soil. A green manure crop supplies organic matter and additional nitrogen and also exercises a protective action against erosion and leaching.


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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


Lichen is the pioneer vegetation on which succession?

  • Hydrosere

  • Lithosere

  • Psammosere

  • Xerosere


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

  • bottleneck effect

  • edge effect

  • junction effect

  • Pasteur effect


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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


Green plants constitute

  •  first trophic level

  • second trophic level

  • third trophic level

  • complete food chain


The effect of intraspecific competition on niches is to make them

  • smaller

  • larger

  • change location

  • more triangular


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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


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