$A$ physical place or set of environmental conditions around the organism to which it must adapt to survive and prosper is . . . . . . .

Define phenotypic adaptation. Give one example.

The ecological niche of a population is a

How is diapause different from hibernation?

Give one example for each of the following:
$(i)$ Eurythermal plant species: $................$.
$(ii)$ $A$ hot water spring organism: $................$.
$(iii)$ An organism seen in deep ocean trenches: $................$.
$(iv)$ An organism seen in a compost pit: $................$.
$(v)$ $A$ parasitic angiosperm: $................$.
$(vi)$ $A$ stenothermal plant species: $................$.
$(vii)$ Soil organism: $................$.
$(viii)$ $A$ benthic animal: $................$.
$(ix)$ Antifreeze compound seen in Antarctic fish: $................$.
$(x)$ An organism which can conform: $................$.

Despite variations in external environment,organisms try to maintain constancy of its internal environment which is called . . . . . . .