Which of these best distinguishes a prokaryotic cell from a eukaryotic cell?

Options

A. Prokaryotic cells have a cell wall, but eukaryotic cells never do
B. Prokaryotic cells have flagella, but eukaryotic cells do not
C. Prokaryotic cells do not have a membrane-bounded nucleus, but eukaryotic cells do have such nucleus
D. Prokaryotic cells have ribosomes but eukaryotic cells do not have ribosomes

Explanation

To distinguish a prokaryotic cell from a eukaryotic cell, we can analyze the given options step by step:

### Step-by-Step Solution:

1. **Understand the Definitions**:
- **Prokaryotic Cells**: These are simple, unicellular organisms that lack a membrane-bound nucleus and organelles. Examples include bacteria and archaea.
- **Eukaryotic Cells**: These are more complex cells that have a membrane-bound nucleus and organelles. Examples include plant cells, animal cells, and fungal cells.

2. **Analyze Each Option**:
- **Option A**: "Prokaryotic cells have a cell wall but eukaryotic cells never do."
- **Analysis**: This statement is incorrect because many eukaryotic cells, such as plant cells, do have a cell wall.

- **Option B**: "Prokaryotic cells have flagella but eukaryotic cells do not have flagella."
- **Analysis**: This statement is misleading. While prokaryotic cells can have flagella, eukaryotic cells can also have flagella (e.g., sperm cells) and cilia. Thus, this option is not a distinguishing feature.

- **Option C**: "Prokaryotic cells do not have a membrane-bound nucleus but eukaryotic cells do have such a nucleus."
- **Analysis**: This statement is correct. Prokaryotic cells have a nucleoid region instead of a membrane-bound nucleus, while eukaryotic cells possess a true membrane-bound nucleus.

- **Option D**: "Prokaryotic cells have ribosomes but eukaryotic cells do not have ribosomes."
- **Analysis**: This statement is false. Both prokaryotic and eukaryotic cells have ribosomes, although they differ in size and structure.

3. **Conclusion**:
- The best distinguishing feature between prokaryotic and eukaryotic cells is found in **Option C**: "Prokaryotic cells do not have a membrane-bound nucleus but eukaryotic cells do have such a nucleus."

### Final Answer:
The best option that distinguishes a prokaryotic cell from a eukaryotic cell is **Option C**.

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