The flow of organic matter in a food chain is unidirectional.

Which group of organisms are not constituents of a food chain?
$(i)$ Grass,lion,rabbit,wolf
$(ii)$ Plankton,man,fish,grasshopper
$(iii)$ Wolf,grass,snake,tiger
$(iv)$ Frog,snake,eagle,grass,grasshopper

Write the appropriate names of the trophic levels $Z$ and $X$ in the figure given below.

An ecosystem is an interacting system made up of $.......$

How does the concentration of a pesticide change once it enters a food chain?

Give the full form of $CFC$.