Reverse transcription occurs in

Options

A. Some viruses
B. Some prokaryotes
C. All viruses
D. All organisms

Answer

**Step-by-Step Solution:**

1. **Understanding Reverse Transcription:**
- Reverse transcription is the process where RNA is converted into complementary DNA (cDNA). This is the reverse of the normal transcription process, which converts DNA into RNA.

2. **Identifying the Enzyme:**
- The enzyme responsible for reverse transcription is called reverse transcriptase. This enzyme catalyzes the conversion of RNA into cDNA.

3. **Occurrence of Reverse Transcription:**
- Reverse transcription primarily occurs in certain types of viruses, specifically retroviruses. Retroviruses have RNA as their genetic material and utilize reverse transcription to replicate.

4. **Examples of Viruses:**
- A well-known example of a retrovirus is the Human Immunodeficiency Virus (HIV). In HIV, the RNA genome is reverse transcribed into cDNA, which then integrates into the host's DNA.

5. **Evaluating the Options:**
- The options provided are:
- Some viruses
- Some prokaryotes
- All viruses
- All organisms
- Based on the understanding of reverse transcription, the correct answer is "some viruses," as it specifically refers to retroviruses like HIV.

6. **Conclusion:**
- Therefore, the correct answer to the question "Reverse transcription occurs in" is **some viruses**.

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