Select the WRONG statement regarding energy flow in an ecosystem.

Options

A. Energy flow in one direction only
B. About 1-5% of the energy reaching the ground is converted by the green plants into chemical energy .
C. Energy requirement for maintenance of body gradually decreases in successive tropic levels.
D. Only 10% of the gross productivity of producers is entrapped by herbivores for their body building .

Answer

To solve the question of selecting the WRONG statement regarding energy flow in an ecosystem, we will analyze each option provided in the context of the principles of energy flow.

### Step-by-Step Solution:

1. **Understand Energy Flow in Ecosystems**:
- Energy flow in an ecosystem follows the 10% law, which states that only about 10% of the energy is transferred from one trophic level to the next.

2. **Evaluate Each Statement**:
- **Option 1**: "Energy flow is in one direction only."
- This statement is **correct**. Energy flows from producers to consumers and cannot flow back.

- **Option 2**: "About 1 to 5% of the energy reaching the ground is converted by the green plants into chemical energy."
- This statement is **correct**. Only a small percentage of solar energy is converted into chemical energy through photosynthesis.

- **Option 3**: "Energy requirement for maintenance of body gradually decreases in successive trophic levels."
- This statement is **WRONG**. The energy requirement for maintenance of the body actually increases at higher trophic levels due to increased complexity and metabolic needs.

- **Option 4**: "Only 10% of the gross productivity of producers is interrupted by the herbivores for their bodybuilding."
- This statement is **correct**. It aligns with the 10% rule, where only a fraction of the energy is available to the next trophic level.

3. **Conclusion**:
- After evaluating all the statements, we find that **Option 3** is the only incorrect statement regarding energy flow in an ecosystem.

### Final Answer:
The WRONG statement regarding energy flow in an ecosystem is **Option 3**: "Energy requirement for maintenance of body gradually decreases in successive trophic levels."