Primary succession is the development of communities on:

Choose the correct statement regarding trophic levels in an ecosystem.

The important function of the trophic level is .....

What is formed by the interactions between biological communities and their environment?

The organisms living at the bottom of a water body are known as:

Consider the following statements about the carbon cycle and choose how many statements are correct?
$(a)$ The atmosphere contains $71\;\%$ of the total global carbon.
$(b)$ Decomposers contribute substantially to the $CO_2$ pool by processing waste materials and dead organic matter from land or oceans.
$(c)$ $4 \times 10^{13}\; kg$ of carbon is fixed through photosynthesis annually.
$(d)$ There is no respiratory input into the atmosphere.
$(e)$ Carbon constitutes $49\;\%$ of the dry weight of organisms.