What are trophic levels? Give an example of a food chain and state the different trophic levels in it. (CBSE 2010)

Trophic levels are the steps in a food chain where transfer of food in the form of energy takes place between organisms. At each step in a food chain is an organism that forms the trophic level.

A food chain consisting of four trophic levels

Grass → Grasshopper/insect → Frog→ Snake→Peacock

Trophic levels - (Producers) – (Primary consumer) — (Secondary consumer) — (Tertiary consumer)

In this food chain, the grass is a producer (First trophic level). insect/ grasshopper is a herbivore and eats grass. Thus, the insect is at the second trophic level. Insect, in turn, is eaten by frog (Carnivores I). Thus frog is at a third trophic level. The frog is eaten by a snake (Carnivores II ). Thus snake is at the fourth trophic level. Snake, in turn, is eaten by peacock( Carnivores III ). Thus, the peacock is at the fifth trophic level.