What does $Allen's$ rule represent?

$A$ plant species shows several morphological variations in response to altitudinal gradient. When grown under similar conditions of growth,the morphological variations disappear and all the variants have common morphology. What are these variants called?

Alpine forests occur at altitudes of:

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

Rhododendron is a characteristic plant of which region?

Sal and teak are dominant in