Animals which live at the bottom of the sea are known as:

In ecology,what is referred to as a 'niche'?

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 $Q$.
$P$ $Q$

Read the following statements and select the option that represents the correct statements.
$(1)$ Kangaroo rats never drink water.
$(2)$ Birds undergo hibernation to escape adverse environmental conditions.
$(3)$ Thermal adaptation can be explained by Allen's Rule.
$(4)$ Opuntia possesses phylloclade for protection.

Community is:
$I.$ Group of independent,interacting populations of same species
$II.$ Group of independent and interacting populations of same species in specific area
$III.$ Group of independent interacting populations of different species in a specific area
$IV.$ Group of independent and interacting populations of different species in different area
Select the correct option.

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