Name the microorganisms which require host cells to reproduce and complete their life cycle .

Options

A. Algae
B. Virus
C. Bacteria
D. Fungi

Explanation

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for microorganisms that need host cells to reproduce and complete their life cycle. This indicates we are looking for organisms that cannot reproduce independently.

2. **Identifying the Options**: The options provided are:
- A. Bacteria
- B. Virus
- C. Fungi
- D. None of the above

3. **Analyzing Each Option**:
- **Bacteria**: Bacteria are single-celled organisms that can reproduce independently through binary fission. They do not require a host cell for reproduction.
- **Virus**: Viruses are unique microorganisms that cannot reproduce on their own. They require a host cell to replicate and complete their life cycle. They enter a living cell, hijack the cell's machinery, and use it to produce new virus particles.
- **Fungi**: Fungi are also independent organisms that can reproduce through spores and do not require a host cell for reproduction.

4. **Conclusion**: Based on the analysis, the only microorganism that requires host cells to reproduce and complete its life cycle is the virus.

5. **Final Answer**: The microorganism that requires host cells to reproduce and complete its life cycle is **Virus**.

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