question_answer

How adaptation is helpful in the survival of Antarctic fish (Trematomus) which can remain active even in extremely cold sea water.

Or

How does coextinction cause loss of biodiversity? Explain by giving an example, write other three factors of evil quartet which cause biodiversity loss.

Answer:

Antarctic fish (Trematomus) remains active even in extremely cold sea water due to hardiness. Cold hardiness is achieved by developing extra solutes in the body fluids and special ice nucleating proteins in the extracellular spaces. The extra solutes which prevent freezing are glycerol and antifreeze proteins. They lower the freezing point of body fluids. Thus, they adapt themselves to tolerate very low temperatures.

Or

Coextinction refers to the indirect extinction of a species as a result of the extinction of another species on which the first one was dependent. Coextinctions occur due to inter - connectedness of organisms, e.g. extinction of a type of Hibiscus due to extinction of its pollinator species, like honey creeper bird. Other factors of evil quartet which cause biodiversity loss are as follows

(i) Over - exploitation

(ii) Alien species Invasion

(iii) Loss and fragmentation of habitat.