Structurally a complete mature virus particle outside the host is called

Options

A. Vira
B. Virus
C. Virion
D. Viroid

Answer

To solve the question, "Structurally a complete mature virus particle outside the host is called," we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Viruses**:
- Viruses are classified as small obligate intracellular parasites. This means they cannot reproduce or carry out metabolic processes outside of a host cell.

2. **Components of a Virus**:
- A virus consists of genetic material, which can be either RNA or DNA. This genetic material is essential for the virus's ability to replicate once it enters a host cell.

3. **Protein Coat**:
- The genetic material of a virus is surrounded by a protective protein coat known as a capsid. The capsid serves to protect the viral genome and aids in the delivery of the virus into host cells.

4. **Definition of a Complete Virus Particle**:
- When a virus is outside of a host cell and is structurally complete and mature, it is referred to as a "virion." This term specifically denotes the entire virus particle, including its genetic material and protein coat.

5. **Conclusion**:
- Therefore, the answer to the question is that a structurally complete mature virus particle outside the host is called a **virion**.

### Final Answer:
A structurally complete mature virus particle outside the host is called a **virion**.

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