Multiple Choice Questions

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Nitrifying bacteria are able to

  • convert atmospheric nitrogen into soluble forms

  • convert ammonia to nitrate

  • ammonia to nitrogen

  • nitrate to nitrogen


B.

convert ammonia to nitrate

Most of the ammonia produced in the soil is acted upon by nitrifying bacteria. Ammonia is changed to nitrate. The reaction occurs in two steps nitrite formation (eg, Nitrosomonas) and nitrate formation (eg, Nitrobacter).


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the group of Anamniota includes

  • reptiles and birds

  • birds and mammals

  • fishes an amphibians

  • reptiles and mammals


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


Gases found in primitive atmosphere are

  • CH4, NH3, H2, H2O (vapour form)

  • CH4, NH3, CO2, H2O

  • CH4, H2O, CO2

  • CH4, O2, CO2


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Lichen is the pioneer vegetation on which succession?

  • Hydrosere

  • Lithosere

  • Psammosere

  • Xerosere


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


Which of the following is used as green manure?

  • Azolla

  • Azadirachta

  • Crotolaria juncea

  • Hevea brassiliansis


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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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