Select incorrect statement regarding prokaryotes.

Options

A. Prokaryotes have something unique in the form of inclusions.
B. Mesosome is a specialised undifferentiated form of cell membrane
C. Bacteria have small circular DNA
D. Pili help in attachment and DNA transfer

Answer

To solve the question of selecting the incorrect statement regarding prokaryotes, we will analyze each statement provided in the options.

### Step-by-Step Solution:

1. **Understanding Prokaryotes**: Prokaryotes are single-celled organisms that lack a nucleus and membrane-bound organelles. They include bacteria and archaea.

2. **Analyzing Statement 1**:
- **Statement**: "Prokaryotes have something unique in the form of inclusions."
- **Evaluation**: This statement is correct. Prokaryotes do store nutrients and other substances in structures called inclusion bodies, which are granules found within the cell.

3. **Analyzing Statement 2**:
- **Statement**: "Mesosome is the specialized undifferentiated form of the cell membrane."
- **Evaluation**: This statement is incorrect. Mesosomes are actually invaginations (infoldings) of the plasma membrane in prokaryotic cells, primarily bacteria, and are not classified as a specialized undifferentiated form of the cell membrane.

4. **Analyzing Statement 3**:
- **Statement**: "Bacteria have small circular DNA."
- **Evaluation**: This statement is correct. Bacteria typically possess a single, circular strand of DNA, which is distinct from the linear DNA found in eukaryotic cells.

5. **Analyzing Statement 4**:
- **Statement**: "Pili help in the attachment and the DNA transfer."
- **Evaluation**: This statement is also correct. Pili (or fimbriae) are hair-like structures on the surface of bacteria that facilitate attachment to surfaces and play a role in the transfer of DNA between bacterial cells.

6. **Conclusion**: After evaluating all statements, the incorrect statement regarding prokaryotes is **Statement 2**.

### Final Answer:
The incorrect statement regarding prokaryotes is: **"Mesosome is the specialized undifferentiated form of the cell membrane."**

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