The infoldings of plasma membrane in a bacterial cell form

Options

A. pili
B. plasmid
C. mesosomes
D. fimbriae

Answer

### Step-by-Step Solution:

1. **Understanding the Structure of Bacterial Cells**:
- Bacterial cells are prokaryotic, meaning they lack a defined nucleus and membrane-bound organelles. They have a cell wall and a plasma membrane.

2. **Identifying Infoldings of the Plasma Membrane**:
- Within the bacterial cell, the plasma membrane can exhibit infoldings. These structures are important for various cellular functions.

3. **Naming the Infoldings**:
- The infoldings of the plasma membrane in bacterial cells are specifically called **mesosomes**.

4. **Functions of Mesosomes**:
- Mesosomes play several critical roles in bacterial cells:
- **Cellular Respiration**: They assist in the process of cellular respiration, which is vital for energy production.
- **Increasing Surface Area**: By increasing the surface area of the plasma membrane, mesosomes enhance the efficiency of cellular respiration.
- **DNA Replication**: Mesosomes are involved in the process of DNA replication, aiding in the formation of daughter cells during cell division.

5. **Significance of Mesosomes in Prokaryotes**:
- Mesosomes are unique to prokaryotic cells. In eukaryotic cells, cellular processes such as respiration and DNA replication occur in membrane-bound organelles, which eliminates the need for such infoldings.

6. **Conclusion**:
- Therefore, the infoldings of the plasma membrane in a bacterial cell are known as **mesosomes**.

### Final Answer:
The infoldings of the plasma membrane in a bacterial cell form **mesosomes**.

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