During adverse seasons,therophytes survive by:

Many tribes live in the high altitude of the Himalayas. What physiological adaptation do they exhibit?

Assertion : Biotic community has higher position than population in ecological hierarchy.
Reason : Population of similar individuals remains isolated in the community.

Many freshwater fishes cannot live in seawater and vice versa because of:

$A$: Some organisms can maintain internal homeostasis by means of physiological processes and are called 'Regulators'.
$R$: 'Regulators' can maintain internal homeostasis only up to a limit of stressful conditions.

$A$ kind of similarity found in polar regions and high altitudes is