Retroviruses have no DNA. However, the DNA of the infected host cell does possess viral DNA. How is it possible ?

Explanation

**Step-by-Step Solution:**

1. **Understanding Retroviruses**: Retroviruses are a type of virus that primarily contain RNA as their genetic material instead of DNA. This is an important characteristic that distinguishes them from other viruses.

2. **Infection Process**: When a retrovirus infects a host cell, it enters the cell and releases its RNA genome into the host's cytoplasm.

3. **Reverse Transcription**: The RNA genome of the retrovirus is then converted into DNA. This process is facilitated by an enzyme called reverse transcriptase, which is unique to retroviruses. This enzyme synthesizes a complementary DNA strand from the viral RNA.

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