The protein coat of virus is called

Options

A. Capsid
B. Virion
C. Viroid
D. Bacterial wall

Answer

To answer the question "The protein coat of virus is called," we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Virus Structure**:
- Viruses consist of two main components: nucleic acid (either DNA or RNA) and a protein coat.

2. **Identifying the Protein Coat**:
- The protein coat that surrounds and protects the viral genetic material is specifically referred to as the "capsid."

3. **Defining Capsid**:
- A capsid is made up of protein subunits known as capsomeres. These capsomeres come together to form the protective shell around the viral nucleic acid.

4. **Eliminating Incorrect Options**:
- The other options provided (virion, viroid, and bacterial worm) do not refer to the protein coat:
- **Virion**: This term refers to the complete virus particle, which includes the nucleic acid and the capsid.
- **Viroid**: This is a type of infectious agent composed solely of a short strand of circular RNA, without a protein coat.
- **Bacterial worm**: This term does not relate to viruses at all.

5. **Conclusion**:
- Based on the above information, the correct answer to the question is "capsid."

### Final Answer:
The protein coat of a virus is called **capsid**.

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