Viruses have

Options

A. Both DNA and RNA
B. DNA enclosed in a protein coat
C. Prokaryotic nucleus
D. Single chromosome

Answer

**Step-by-Step Solution:**

1. **Understanding Viruses**: Viruses are acellular entities that exhibit characteristics of both living and non-living organisms. They are not classified within the five kingdoms of life due to this unique nature.

2. **Evaluating the Options**:
- **Option 1**: "Viruses have both DNA and RNA."
- This is incorrect because viruses can have either DNA or RNA, but not both simultaneously. They are classified as either deoxyriboviruses (with DNA) or riboviruses (with RNA).

- **Option 2**: "DNA enclosed in a protein coat."
- This option is misleading. While viruses do have a protein coat (capsid) that protects their genetic material, they can also have RNA as their genetic material. Therefore, this option is not entirely accurate.

- **Option 3**: "Prokaryotic nucleus."
- This option is incorrect because viruses do not possess a nucleus, prokaryotic or otherwise. They lack cellular structures entirely.

- **Option 4**: "Viruses have got a single molecule of the chromosome."
- This is the correct option. Viruses contain a single molecule of nucleic acid (either DNA or RNA), which serves as their chromosome.

3. **Conclusion**: The correct characteristic feature of viruses is that they have a single molecule of nucleic acid, which can be either DNA or RNA, but not both.

**Final Answer**: Viruses have a single molecule of the chromosome (either DNA or RNA).

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