Which base is responsible for hotspots for spontaneous point mutations?

Options

A. Guanine
B. Adenine
C. 5-bromouracil
D. 5-methylcytosine

Explanation

**Step-by-Step Solution:**

1. **Understanding the Question:**
The question asks which base is responsible for hotspots for spontaneous point mutations. We need to identify the base that is known to induce such mutations.

2. **Analyzing the Options:**
The options provided include:
- Guanine
- Adenine
- 5-methylcytosine
- 5-bromo-uracil

3. **Identifying the Characteristics of Each Base:**
- **Guanine:** A purine that pairs with cytosine. Not typically associated with hotspots for mutations.
- **Adenine:** Another purine that pairs with thymine. Again, not known for causing hotspots.
- **5-methylcytosine:** A methylated form of cytosine involved in gene regulation, but not directly linked to spontaneous mutations.
- **5-bromo-uracil:** A brominated form of uracil that can substitute for thymine in DNA. It pairs with adenine instead of thymine, which can lead to point mutations.

4. **Conclusion:**
Based on the analysis, 5-bromo-uracil is the base responsible for creating hotspots for spontaneous point mutations due to its ability to mispair with adenine.

5. **Final Answer:**
The base responsible for hotspots for spontaneous point mutations is **5-bromo-uracil**.

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