They help in respiration , They help in cell wall formation
They help in DNA replication , They increase surface area of plasma membrane. They are prokaryotic structures.

Options

A. Chromosomes
B. Ribosomes
C. Mesosomes
D. Lysosomes.

Answer

To solve the question regarding the prokaryotic structures that help in respiration, cell wall formation, DNA replication, and increase the surface area of the plasma membrane, we can analyze the options provided step by step.

### Step-by-Step Solution:

1. **Identify the Structures**: The question mentions several functions: respiration, cell wall formation, DNA replication, and increasing the surface area of the plasma membrane. We need to identify which prokaryotic structure fulfills all these functions.

2. **Evaluate Chromosomes**:
- Chromosomes are structures that carry genetic information.
- They do not participate in respiration, cell wall formation, or increasing the surface area of the plasma membrane.
- **Conclusion**: Chromosomes do not fit the criteria.

3. **Evaluate Ribosomes**:
- Ribosomes are involved in protein synthesis.
- They do not play a direct role in respiration, cell wall formation, or increasing the surface area of the plasma membrane.
- **Conclusion**: Ribosomes do not fit the criteria.

4. **Evaluate Mesosomes**:
- Mesosomes are invaginations of the plasma membrane found in prokaryotes (specifically bacteria).
- They help in respiration by containing respiratory enzymes.
- They assist in cell wall formation.
- They play a role in DNA replication.
- They increase the surface area of the plasma membrane.
- **Conclusion**: Mesosomes fulfill all the criteria mentioned in the question.

5. **Evaluate Lysosomes**:
- Lysosomes are organelles containing hydrolytic enzymes and are primarily found in eukaryotic cells.
- They do not participate in the functions listed in the question.
- **Conclusion**: Lysosomes do not fit the criteria.

6. **Final Conclusion**: The only structure that meets all the criteria (helps in respiration, cell wall formation, DNA replication, and increases the surface area of the plasma membrane) is **mesosomes**.

### Answer:
The correct option is **mesosomes**.

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