Question

6. Assertion. Food chain cannot have more than four trophic levels.
Reason. The loss of energy at each step is so great that very little usable
energy remains after four trophic levels.​

Answer 1

THE loss of energy explains why there are rarely more than four trophic levels in a food chain or web. Sometimes there may be a fifth trophic level, but usually there’s not enough energy left to support any additional levels.

Explanation:

Energy is passed up a food chain or web from lower to higher trophic levels. However, generally only about 10 percent of the energy at one level is available to the next level. happens to the other 90 percent of energy? It is used for metabolic processes or given off to the environment as heat.