Which of the following limits the number of trophic levels in a food chain?

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

Which of the following are called secondary consumers?

Mention one negative effect of our affluent lifestyle on the environment.

Write any two consequences if decomposers are removed from the ecosystem.

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