Viruses possess

Options

A. DNA only
B. Nucleic acid, DNA or RNA
C. Protein only
D. Nucleic acid and protein

Answer

### Step-by-Step Solution:

1. **Understanding the Structure of Viruses**:
- Viruses are composed of several key components. The primary components include nucleic acid (which can be either DNA or RNA) and a protein coat known as the capsid.

2. **Identifying the Genetic Material**:
- The genetic material in viruses can be either DNA or RNA. This nucleic acid can be single-stranded or double-stranded.

3. **Capsid Structure**:
- The capsid is a protective protein coat that surrounds the nucleic acid. It is made up of smaller units called capsomeres.

4. **Presence of an Envelope**:
- Some viruses have an additional outer layer called an envelope, which is composed of lipids, proteins, and carbohydrates. Viruses without this envelope are referred to as naked viruses.

5. **Enzymes in Viruses**:
- Certain viruses may also contain enzymes, such as reverse transcriptase, which is involved in the replication of the viral genome.

6. **Evaluating the Options**:
- When considering the options provided in the question, we need to determine which components are present in viruses. The correct answer should reflect that viruses possess both nucleic acid (DNA or RNA) and a protein coat (capsid).

7. **Conclusion**:
- The correct answer to the question "Viruses possess" is that they possess nucleic acid (DNA or RNA) and a protein coat (capsid).

### Final Answer:
Viruses possess nucleic acid (DNA or RNA) and a protein coat (capsid).

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