statement A: same organisms always occupy only one specific tophic level in a food web. statement B: a species may occupy more than one trophic level in the same ecosystem at the same time

Options

A. only statement A is correct
B. only statement B is correct
C. Both statements A and B are correct
D. both statements A and B are incorrect

Answer

To solve the question regarding the two statements about trophic levels in a food web, we will analyze each statement step by step.

### Step-by-Step Solution:

1. **Understanding Statement A**:
- Statement A claims that the same organisms always occupy only one specific trophic level in a food web.
- In a food web, organisms are categorized into different trophic levels: producers, primary consumers, secondary consumers, and tertiary consumers.
- For example, a sparrow can feed on fruits and seeds (acting as a primary consumer) and also on insects (acting as a secondary consumer). This indicates that the same organism can occupy different trophic levels depending on its food sources.

**Conclusion for Statement A**: This statement is incorrect because an organism can occupy multiple trophic levels.

**Hint for Step 1**: Consider examples of organisms that can consume different types of food and how that affects their trophic level.

2. **Understanding Statement B**:
- Statement B states that a species may occupy more than one trophic level in the same ecosystem at the same time.
- As established in the example of the sparrow, it can simultaneously act as a primary consumer (when eating seeds) and a secondary consumer (when eating insects).
- This supports the idea that a single species can function at multiple trophic levels within the same ecosystem.

**Conclusion for Statement B**: This statement is correct because species can occupy multiple trophic levels simultaneously.

**Hint for Step 2**: Think about how different feeding habits of the same species can allow it to fit into various roles in the ecosystem.

3. **Final Evaluation**:
- Since Statement A is incorrect and Statement B is correct, the overall conclusion is that only Statement B holds true.

### Final Answer:
- **Statement A is incorrect.**
- **Statement B is correct.**
- Therefore, the correct answer is that only Statement B is correct.