Viruses are considered as a living organism because it

Options

A. reproduces inside the host cell.
B. Can multiple outside the host cell.
C. respond to touch stimuli.
D. respires

Answer

To solve the question "Viruses are considered as a living organism because it...", we will analyze the options provided and determine which one correctly describes the characteristics of viruses that justify their classification as living organisms.

### Step-by-Step Solution:

1. **Understanding the Nature of Viruses**:
- Viruses are unique entities that exhibit characteristics of both living and non-living things. They cannot carry out metabolic processes on their own and are dependent on host cells for replication.

2. **Evaluating the Options**:
- **Option 1: Reproduces inside the host cell**:
- This is true. Viruses can only reproduce by infecting a host cell and using the host's cellular machinery to replicate their genetic material and produce new virus particles. This characteristic is a strong argument for considering them as living organisms when they are inside a host.

- **Option 2: Can multiply outside the host cell**:
- This is false. Viruses cannot multiply or reproduce outside of a host cell. They require a living host to replicate, which is a key distinction from living organisms that can reproduce independently.

- **Option 3: Respond to touch stimuli**:
- This is also false. Viruses do not have the ability to respond to stimuli like living organisms do. They lack the cellular structures necessary for such responses.

- **Option 4: Respire**:
- This is incorrect as well. Viruses do not carry out respiration. They do not have metabolic processes and do not consume energy in the way living organisms do.

3. **Conclusion**:
- Based on the analysis, the correct answer is **Option 1: Reproduces inside the host cell**. This is the primary reason why viruses are sometimes considered living organisms, as they exhibit the ability to reproduce, but only within a suitable host.

### Final Answer:
Viruses are considered as living organisms because they reproduce inside the host cell.