Harmful chemicals enter into our body through biological magnification.

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

Suggest a sequence of suitable methods for the disposal of waste produced at your home to minimize environmental pollution.

"Energy flow in a food chain is unidirectional." Justify this statement. Explain how the pesticides enter a food chain and subsequently get into our body.

Differentiate between biodegradable and non-biodegradable substances. Cite examples.

Which of the following groups contain only biodegradable items?