Depletion of ozone is mainly due to

What is the difference between the food habits of organisms belonging to the second and fourth trophic levels? Give one example of organisms belonging to each of these two trophic levels.

Indicate the flow of energy in an ecosystem. Why is it unidirectional? Justify.

Select the mismatched pair in the following and correct it.
$(a)$ Biomagnification — Accumulation of chemicals at the successive trophic levels of a food chain
$(b)$ Ecosystem — Biotic components of environment
$(c)$ Aquarium — $A$ man-made ecosystem
$(d)$ Parasites — Organisms which obtain food from other living organisms

Suggest one word for each of the following statements/definitions:
$(a)$ The physical and biological world where we live in
$(b)$ Each level of food chain where transfer of energy takes place
$(c)$ The physical factors like temperature,rainfall,wind and soil of an ecosystem
$(d)$ Organisms which depend on the producers either directly or indirectly for food

Give one protective function of forests.