State whether the following statements are true or false. Facultative anaerobes may live with or without oxygen.
A. True
B. False

Answer

To determine whether the statement "Facultative anaerobes may live with or without oxygen" is true or false, we can analyze the definition and characteristics of facultative anaerobes.

### Step-by-Step Solution:

1. **Definition of Facultative Anaerobes**:
- Facultative anaerobes are organisms that can survive in both the presence and absence of oxygen. They have the ability to switch between aerobic respiration (using oxygen) and anaerobic respiration (without oxygen).

2. **Aerobic Respiration**:
- When oxygen is available, facultative anaerobes utilize aerobic respiration. This process allows them to efficiently break down glucose and produce ATP (energy) in the presence of oxygen.

3. **Anaerobic Respiration**:
- In the absence of oxygen, facultative anaerobes switch to anaerobic respiration. Although this process is less efficient in terms of energy production, they can still produce ATP along with by-products such as ethanol, carbon dioxide, or lactic acid.

4. **Conclusion**:
- Since facultative anaerobes can thrive in both environments (with and without oxygen), the statement is indeed correct.

5. **Final Answer**:
- Therefore, the answer to the question is **A. True**.