Which one is a prokaryote ?

Options

A. Entamoeba
B. Saccharomyces
C. Paramecium
D. E. coli

Answer

To determine which of the given options is a prokaryote, we will analyze each option based on the characteristics of prokaryotic and eukaryotic organisms.

### Step-by-Step Solution:

1. **Understand Prokaryotes and Eukaryotes**:
- Prokaryotes are primitive organisms that lack a true nucleus and membrane-bound organelles. They are unicellular and include organisms from the kingdom Monera.
- Eukaryotes, on the other hand, have a true nucleus and possess membrane-bound organelles such as mitochondria, chloroplasts, and the endoplasmic reticulum.

2. **Analyze the Options**:
- **Option A: Entamoeba**:
- Entamoeba is a protozoan and belongs to the kingdom Protista. It is a unicellular eukaryote, so this option is incorrect.

- **Option B: Saccharomyces**:
- Saccharomyces is a type of yeast that falls under the kingdom Fungi. Yeasts are also eukaryotic organisms, making this option incorrect.

- **Option C: Paramecium**:
- Paramecium is another protozoan and is classified under the kingdom Protista. It is a unicellular eukaryote, thus this option is also incorrect.

- **Option D: E. coli**:
- E. coli (Escherichia coli) is a bacterium and is classified under the kingdom Monera. It is a prokaryotic organism, which makes this option correct.

3. **Conclusion**:
- After analyzing all the options, the only prokaryote among the choices is **E. coli**.

### Final Answer:
**E. coli is a prokaryote.**

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