Rhododendron is the characteristic vegetation of

Do you agree that regional and local variations exist within each biome? Substantiate your answer with suitable examples.

The organism which tolerates a wide range of salinity is called ...$A$...
$II.$ The organism which tolerates a narrow range of salinity is called ...$B$...
Choose the correct option for $A$ and $B$.

How does the kangaroo rat in North American deserts meet all its water requirements?

Animals that do not maintain a constant body temperature are called.....

$I.$ Biochemical adaptations are seen in organisms living at great depths of the ocean to face crushing pressure.
$II.$ Allen's rule explains adaptations in mammals living in colder climates.
$III.$ Altitude sickness is caused because the body does not get enough oxygen due to low atmospheric pressure at high altitudes.
$IV.$ Desert lizards lack behavioural means to manage their body temperature.
Choose the correct option for the above statements.