What is the layer of the atmosphere closest to the Earth called?

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

Accumulation of non-biodegradable pesticides in the food chain in increasing amount at each higher trophic level is known as

Write the common food chain of a pond ecosystem.

How many molecules of ozone can be decomposed by one atom of chlorine?

Depletion of ozone is mainly due to