Viral diseases have no cure because

Options

A. viruses have no cell wall
B. they multiply repeatedly in host cell
C. they do not act as antigen
D. they do not have cytoplasm

Answer

**Step-by-Step Solution:**

1. **Understanding Viruses**: Viruses are unique biological agents that exist in two states: as non-living entities outside of host cells and as living entities when they invade host cells. This dual nature is crucial to understanding why viral diseases are difficult to treat.

2. **Replication Mechanism**: Viruses do not have their own cellular machinery to replicate. Instead, they hijack the host cell's machinery to reproduce. This means that once a virus infects a host cell, it can multiply repeatedly using the host's resources.

3. **Challenges in Treatment**: The primary challenge in curing viral diseases lies in the fact that viruses multiply within host cells. This makes it difficult to target the virus without also harming the host cells. Any treatment must be able to differentiate between the virus and the host's own cells.

4. **Analysis of Options**:
- **Viruses have no cell wall**: This is irrelevant to the treatment of viral diseases. The presence or absence of a cell wall does not affect the ability to cure viral infections.
- **They multiply repeatedly in the host cells**: This is a correct statement and highlights why it is hard to cure viral infections. The continuous replication within host cells complicates the treatment process.
- **They don't act as antigens**: This is incorrect. Viruses do act as antigens, prompting an immune response from the host.
- **They don't have cytoplasm**: This is also irrelevant. While viruses lack cytoplasm, this characteristic does not contribute to the treatment challenges.

5. **Conclusion**: The correct reason why viral diseases have no cure is that viruses multiply repeatedly in the host cells, making it difficult to target them without affecting the host.

**Final Answer**: Viruses multiply repeatedly in the host cells, making it hard to cure viral diseases.

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