In summer,when the outside temperature is higher than our body temperature,we sweat profusely. The resulting evaporative cooling,similar to what happens with a desert cooler in operation,brings down the body temperature. In winter,when the temperature is much lower than $37^{\circ}C$,we start to shiver,a kind of exercise which produces heat and raises the body temperature. These organisms are called:

The organisms should try to maintain the constancy of its internal environment is a process called .......

How can seals survive in a polar climate where the temperature prevails below $0^{\circ} C$?

Match Column-$I$ with Column-$II$ and choose the correct option.

Column-$I$	Column-$II$
$a.$ Aestivation	$(i)$ Over wintering
$b.$ Hibernation	$(ii)$ Over summer
$c.$ Diapause	$(iii)$ Suspended development in zooplanktons

Consider the following four statements $(a-d)$ regarding certain desert animals like the kangaroo rat:
$(a)$ They have a dark color and high rate of reproduction and excrete solid urine.
$(b)$ They do not drink water,breathe at a slow rate to conserve water,and their body is covered with thick hair.
$(c)$ They feed on dry seeds and do not require drinking water.
$(d)$ They excrete very concentrated urine and do not use water to regulate body temperature.
Which two of the above statements are true?

The genus $Quercus$ is a dominant component in: