Community is a group of independent and interacting population of

$I.$ 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.

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 $B$.

What is formed by the populations of different species living together in a common habitat?

Adaptations of organisms can be related to which of the following?

$I.$ Many xerophytic plants have thick cuticle on leaf epidermis and sunken stomata.
$II.$ Some xerophytic plants have a special photosynthetic pathway $(CAM)$ that enables their stomata to close during the day.
$III.$ $Opuntia$ has spines (modified leaves) and a photosynthetic phylloclade (stem).
$IV.$ All adaptations are genetically fixed in all organisms.
Choose the combination of correct statements.