Question

What does a food chain represent? “The number of trophic levels in a food chain is limited.” Give an example stating reason to justify this statement.

Answer 1

Step 1: What does a food chain represent?
A food chain represents the sequence of organisms through which energy and nutrients are passed in an ecosystem. Each organism in the chain serves as food for the next level, starting from producers (like plants) to consumers (herbivores, carnivores) and decomposers. It shows the flow of energy from one organism to another.

Step 2: Explanation of the statement "The number of trophic levels in a food chain is limited"
The number of trophic levels in a food chain is limited due to the energy loss at each level. According to the 10% energy rule, only about 10% of the energy at one trophic level is transferred to the next level; the rest is lost as heat, used for metabolism, or lost in waste. This significant energy loss limits the number of trophic levels because there is not enough energy to support more levels beyond a certain point.

Step 3: Example to justify the statement
In a typical food chain, we have:
- Producers (plants) → Primary consumers (herbivores) → Secondary consumers (carnivores) → Tertiary consumers (top predators).
For example, consider the food chain:
- Grass → Grasshopper → Frog → Snake.
At each level, energy is lost as heat and metabolic processes. After a few trophic levels, there isn’t enough energy left to support another level, so the food chain typically ends with the top predators, and any additional levels would not be sustainable.

Conclusion:
The number of trophic levels in a food chain is limited because of energy loss at each level, making it impossible to sustain more than a few levels in a typical ecosystem.