A virus can be considered as living entity because

Options

A. reproduces (inside the host)
B. can cause disease
C. response to touch stimulus
D. shows metabolism.

Answer

### Step-by-Step Solution:

1. **Understanding Viruses**:
- Viruses are classified as acellular entities, meaning they do not have a cellular structure like living organisms (e.g., plants, animals, bacteria).

2. **Genetic Material**:
- Viruses contain genetic material, which can either be DNA or RNA. This genetic material is essential for their reproduction and functioning.

3. **Protein Coat**:
- The genetic material of viruses is surrounded by a protein coat known as a capsid. This structure helps protect the genetic material and aids in the infection of host cells.

4. **Living vs. Non-Living**:
- Viruses exhibit characteristics of both living and non-living entities. They are considered living when they are inside a host cell, as they can reproduce and carry out life processes. However, outside a host, they do not exhibit any life processes and behave as non-living entities.

5. **Reproduction**:
- The key characteristic that allows viruses to be considered living entities is their ability to reproduce. However, they can only do this by infecting a host cell. Once inside, they hijack the host's cellular machinery to replicate themselves.

6. **Conclusion**:
- Therefore, a virus can be considered a living entity because it can reproduce inside a host cell, which is a fundamental characteristic of living organisms.