During adverse seasons,therophytes survive by:

Animals that do not maintain a constant body temperature are called.....

Most animals are tree dwellers in a

Why do mammals of colder regions generally have shorter ears and limbs?
$I.$ To minimize their surface area to volume ratio
$II.$ To minimize heat loss
$III.$ To maximize their surface area to volume ratio
$IV.$ To maximize heat loss
Choose the correct combination from the given options:

In bacteria,fungi,and lower plants,various kinds of thick-walled spores are formed which help them to survive unfavourable conditions. This phenomenon can be called ...........

How many of the following statements are correct about niche?
$i$. It denotes the functional role played by an organism.
$ii$. It deals with the flow of energy from one organism to another.
$iii$. As soon as a niche is left vacant,other organisms fill that position.
$iv$. The same niche is shared by two or more species.
$v$. Organisms living in the same habitat differ in their niches.