What is the typical temperature range in high-altitude regions,which acts as a significant environmental factor?

In the oceans,the environment is perpetually dark at depths of:

Organisms that can tolerate only a narrow range of salt concentrations are called . . . . . . .

Write a short note on:
$(a)$ Adaptations of desert plants and animals
$(b)$ Adaptations of plants to water scarcity
$(c)$ Behavioural adaptations in animals
$(d)$ Importance of light to plants
$(e)$ Effect of temperature or water scarcity and the adaptations of animals.

Which of the following are the $Key$ elements that cause variation in the physical and chemical conditions of an ecosystem?

Why are stenohaline organisms unable to survive in marine habitats for a long period?