The fraction of energy lost when an organism proceeds from one trophic level to the next trophic level is

Options

A. 10 percent
B. 20 percent
C. 30 percent
D. 90 percent

Answer

To solve the question regarding the fraction of energy lost when an organism moves from one trophic level to the next, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Trophic Levels**: Trophic levels refer to the different stages in a food chain, where organisms are categorized based on their feeding relationships. For example, producers (like plants) are at the first trophic level, herbivores at the second, and carnivores at the third.

2. **Introduce the 10% Law**: The 10% law, proposed by ecologist Lindeman, states that when energy is transferred from one trophic level to the next, only about 10% of the energy is retained by the organism at the higher trophic level.

3. **Calculate Energy Loss**: If 10% of energy is retained, it implies that the remaining energy is lost. Therefore, to find the fraction of energy lost, we can calculate:
- Energy retained = 10%
- Energy lost = 100% - 10% = 90%

4. **Conclusion**: Based on the 10% law, we conclude that when an organism moves from one trophic level to the next, 90% of the energy is lost.

### Final Answer:
The fraction of energy lost when an organism proceeds from one trophic level to the next trophic level is **90%**.

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