Consider the following statements $(A – D)$ each with one or two blanks.

$(A)$ Some snails go into _____$(i)$_____ to avoid ____$(ii)$_____ related problems.
$(B)$ Since small animals have a ____$(iii)$___ surface area relative to their volume, they tend to lose body heat
_____$(iv)$______ when it is cold outside.
$(C)$ Next to temperature, _____$(v)$____ is the most ecologically important environmental factor.
$(D)$ Every ____$(vi)$____ the famous Keolado National Park in Rajasthan host thousands of migrating birds.
Which one of the following option gives the correct fill ups for the respective blank numbers from $(i)$ to $(vi)$ in
the statements?

Distinguish between the following:

$(a)$ Hibernation and Aestivation

$(b)$ Ectotherms and Endotherms

$A$ – The salt concentration is less than $5$ (parts per thousand) in inland waters.

$R$ – The salt concentration is $45 -50$ (parts per thousand) in the sea.

Consider the following four statements $(1-­4)$ about certain desert animals such as kangaroo rat.

$(1)$ They have dark colour and high rate of reproduction and excrete solid urine.

$(2)$ They do not drink water, breathe at a slow rate to conserve water and have their body covered with thick hairs.

$(3)$ They feed on dry seeds and do not require drinking water.

$(4)$ They excrete very concentrated urine and do not use water to regulate body temperature.

Which two of the above statements for such animals are true ?

What is the basis of variations in the physical and chemical conditions of different habitats?