Who discovered retroviruses?

Options

A. HM Temin
B. D Baltimore
C. Both 1 and 2
D. Crick

Answer

**Step-by-Step Solution:**

1. **Understanding Retroviruses**:
- Retroviruses are a group of RNA viruses that have the unique ability to convert their RNA into DNA after entering a host cell. This process is facilitated by an enzyme called reverse transcriptase.

2. **Identifying Key Examples**:
- A well-known example of a retrovirus is the Human Immunodeficiency Virus (HIV), which is responsible for causing Acquired Immunodeficiency Syndrome (AIDS).

3. **Recognizing the Discoverers**:
- The discovery of retroviruses is attributed to two key scientists: Howard Martin Temin (HM Temin) and David Baltimore (D. Baltimore). Both made significant contributions to the understanding of these viruses.

4. **Evaluating the Options**:
- The options provided in the question include:
1. HM Temin
2. D Baltimore
3. Crick
4. Both 1 and 2
- Since both HM Temin and D Baltimore are credited with the discovery of retroviruses, the correct answer is "both 1 and 2".

5. **Conclusion**:
- Therefore, the answer to the question "Who discovered retroviruses?" is "both HM Temin and D Baltimore".