Warm-blooded animals like mammals from colder climates generally have shorter ears and limbs. This is an explanation of:

$A$ regulators are able to maintain homeostasis by means which ensure constant body temperature,constant osmotic concentration,etc. All $B$ and $C$ and a very few lower vertebrate and invertebrate species are indeed capable of such regulation (thermoregulation and osmoregulation).
Evolutionary biologists believe that the 'success' of mammals is largely due to their ability to maintain a constant body $D$ and thrive whether they live in Antarctica or in the Sahara desert.
Choose the correct option for $A, B, C$ and $D$.

Organisms restricted to a narrow range of salinity are $- P$.
Organisms that tolerate a wide range of salinity are $- Q$.
Choose the correct option for $P$ and $Q$.
$P$ $Q$

The wide variety of natural habitats is based on which of the following?

Distinguish between the following:
$(a)$ Hibernation and Aestivation
$(b)$ Ectotherms and Endotherms

Explain how ecology is related to an organism?