The only cell organelle seen in prokaryotic cell

Options

A. Dictyosomes
B. endoplasmic reticulum
C. Mesosome
D. ER

Answer

### Step-by-Step Solution:

1. **Understanding Prokaryotic Cells**: Prokaryotic cells are simple, unicellular organisms that lack a nucleus and membrane-bound organelles. They include bacteria and archaea.

2. **Identifying Organelles**: In prokaryotic cells, the only organelle that can be identified is one that is not membrane-bound, as prokaryotes do not possess membrane-bound organelles like eukaryotic cells do.

3. **Analyzing Options**:
- **Dictyosomes**: These are related to the Golgi apparatus and are found in plant cells, not in prokaryotes.
- **Endoplasmic Reticulum (ER)**: This is a membrane-bound organelle found in eukaryotic cells, so it is absent in prokaryotic cells.
- **Mesosomes**: These are infoldings of the plasma membrane in prokaryotic cells and are considered the only organelle that can be identified in these cells.

4. **Conclusion**: Since mesosomes are the only organelle found in prokaryotic cells, the correct answer to the question is **mesosomes**.

### Final Answer:
The only cell organelle seen in prokaryotic cells is **mesosomes**.

---