Mutations induced by 5-bromo uracil are

Options

A. Transversional mutations
B. Transitional mutations
C. Frame shift mutations
D. Backward mutations

Answer

### Step-by-Step Solution:

1. **Understanding 5-Bromo Uracil**:
- 5-Bromo Uracil (5-BrU) is a base analog that resembles uracil. It can incorporate into DNA in place of thymine due to its structural similarity.

2. **Structure of 5-Bromo Uracil**:
- The structure of 5-Bromo Uracil consists of a pyrimidine ring with a bromine atom attached to the 5th carbon. This makes it similar to thymine, which has a methyl group at the same position.

3. **Mechanism of Mutation**:
- When 5-Bromo Uracil is incorporated into DNA, it can pair with adenine instead of guanine during DNA replication. This mispairing can lead to a transition mutation, where a purine is replaced by another purine or a pyrimidine is replaced by another pyrimidine.

4. **Identifying the Type of Mutation**:
- The incorporation of 5-Bromo Uracil leads to a transition mutation because it causes a change from thymine to uracil, which is a substitution of one base for another of the same class (pyrimidine).

5. **Conclusion**:
- Therefore, the type of mutation induced by 5-Bromo Uracil is a **transitional mutation**.

### Final Answer:
Mutations induced by 5-bromo uracil are **transitional mutations**.

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