Give reason why a food chain cannot have more than four trophic levels

Explanation

### Step-by-Step Solution:

1. **Understanding Trophic Levels**: A food chain consists of different levels called trophic levels, where each level represents a different stage in the flow of energy through an ecosystem. The primary producers (like plants) are at the first trophic level, followed by primary consumers (herbivores), secondary consumers (carnivores), and so on.

2. **Energy Transfer Efficiency**: In a food chain, energy transfer from one trophic level to the next is not 100% efficient. It is generally accepted that only about 10% of the energy from one level is transferred to the next level. This is known as the "10% Rule."

3. **Energy Loss Calculation**: To illustrate this, let's assume:
- Trophic Level 1 (Producers) has 40 joules of energy.
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