Nearly all protists are-

Options

A. Aerobic
B. Anaerobic
C. Aerobic or anaerobic
D. Photosynthetic

Answer

**Step-by-Step Solution:**

1. **Understanding Protists**: The question asks about the nature of protists, which belong to the kingdom Protista. It is important to note that protists are primarily unicellular organisms and are classified as eukaryotic, meaning they have a well-defined nucleus.

2. **Metabolic Requirements**: The next step is to analyze the metabolic requirements of protists. Most protists are aerobic organisms, meaning they require oxygen for their metabolic processes. This is a key characteristic of the majority of protists.

3. **Anaerobic Protists**: While the majority of protists are aerobic, there are some that can survive in anaerobic conditions (without oxygen). These organisms can perform anaerobic metabolism, which allows them to thrive in environments where oxygen is absent. An example of such protists includes certain ciliates found in marine environments that live in sulphide zones.

4. **Conclusion**: Since the question specifies "nearly all protists," it indicates that the majority of them are aerobic. Therefore, the correct answer to the question is that nearly all protists are aerobic organisms.

**Final Answer**: Nearly all protists are aerobic.

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