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

The various steps or levels in a food chain at which the transfer of energy takes place are called trophic levels.

An Example of food chain is:

Grass → grasshopper → frog → snake

• The autotroph or the producer — In the above given food chain grass is the producer. It is at the first trophic level. It fixes up the solar energy and makes it available for heterotrophs or the consumers.

• The herbivores or the primary consumers — They are the second trophic level. In the above given food chain grasshopper is the primary consumer as it feeds on grass.

• Secondary Consumers — They are third trophic level. Small carnivores like frog in the given food chain is the secondary consumer.

• Tertiary consumer — They are the fourth trophic level. Larger carnivores like snake in the given food chain constitute the fourth trophic level.

Different organisms may be on different trophic levels depending upon their position in different food chains.