Penguins are found in:

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:

Match the columns:

Column-$I$	Column-$II$
$(a)$ Bears	$(i)$ Diapause
$(b)$ Snails	$(ii)$ Hibernation
$(c)$ Zooplanktons	$(iii)$ Dormancy
$(d)$ Seeds	$(iv)$ Aestivation

In most animals,the metabolic reactions proceed in a $A$ temperature range (in humans,it is $37^{\circ} C$). But there are microbes (archaebacteria) that flourish in hot springs and deep sea hydrothermal vents where temperatures far exceed $B$. Choose the correct option for $A$ and $B$.

Plants such as $Prosopis$,$Acacia$,and $Capparis$ represent examples of tropical

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.