Question

Define trophic levels. At which trophic level do we find (i) secondary and (ii) tertiary consumers in a food chain? What will happen if all the organisms of a trophic level die? Give reasons to justify your answer.

Hint:

Energy flows through trophic levels — removing one level disrupts the whole chain.

Answer 1

A trophic level is the position or step that an organism occupies in a food chain, representing the flow of energy and nutrients from producers to various levels of consumers.
Trophic Levels:
(i) Secondary consumers occupy the third trophic level in a food chain.
(ii) Tertiary consumers occupy the fourth trophic level in a food chain.
Effect if all organisms of a trophic level die:
If all the organisms of a trophic level die, it will disturb the entire food chain. For example:
- If all secondary consumers die, primary consumers will multiply rapidly because they will not be eaten by secondary consumers.
- This will lead to overgrazing or overuse of producers (plants).
- The imbalance will eventually cause the collapse of the food chain, affecting all other trophic levels.
Therefore, every trophic level is important for maintaining balance in an ecosystem.