Which of the following microbe is made up of protein only?

Options

A. Virus
B. Baceria
C. Viroids
D. Prions

Answer

To determine which microbe is made up of protein only, we will analyze each option provided: virus, bacteria, viroids, and prions.

### Step-by-Step Solution:

1. **Understanding Viruses**:
- Viruses consist of genetic material (either DNA or RNA) surrounded by a protein coat. Therefore, they are not made up of protein only.
- **Conclusion**: Virus is not the answer.

2. **Understanding Bacteria**:
- Bacteria are unicellular organisms that contain genetic material (DNA), a cell wall, and various cellular components, including proteins. They are complex and not made up of protein only.
- **Conclusion**: Bacteria is not the answer.

3. **Understanding Viroids**:
- Viroids are infectious agents composed solely of a short strand of circular RNA. They do not contain proteins, making them distinct from other microbes.
- **Conclusion**: Viroids is not the answer.

4. **Understanding Prions**:
- Prions are infectious proteins that cause neurodegenerative diseases. They are unique because they consist entirely of protein without any nucleic acids (DNA or RNA).
- **Conclusion**: Prions are made up of protein only.

### Final Answer:
The microbe that is made up of protein only is **prions**.

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