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

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

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

Which of the following is used as green manure?

• Azolla

• Azadirachta

• Crotolaria juncea

• Hevea brassiliansis