Type of gene mutation which involves replacement of purine with pyrimidine or vice versa or the substitution of one type of base with another type of base is

Options

A. Transduction
B. Transversion
C. Translocation
D. Transcription

Answer

To solve the question regarding the type of gene mutation that involves the replacement of a purine with a pyrimidine or vice versa, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Types of Bases**:
- There are two categories of nitrogenous bases: purines (adenine and guanine) and pyrimidines (cytosine, thymine, and uracil).

2. **Identify the Mutation Types**:
- Gene mutations can involve various types of changes, including substitutions, deletions, and insertions. The question specifically asks about substitution mutations.

3. **Define Transduction**:
- Transduction refers to the process of transferring genetic material from one bacterium to another via a virus. This does not involve base substitution, so it is not the correct answer.

4. **Define Transversion**:
- A transversion mutation is a specific type of base substitution where a purine is replaced by a pyrimidine or a pyrimidine is replaced by a purine. For example, adenine (purine) can be replaced by cytosine (pyrimidine).

5. **Define Translocation**:
- Translocation involves the rearrangement of chromosomal segments between non-homologous chromosomes. This does not pertain to base substitution, making it an incorrect option.

6. **Define Transcription**:
- Transcription is the process of synthesizing RNA from a DNA template. This process does not involve the substitution of bases, so it is also not the correct answer.

7. **Conclusion**:
- Based on the definitions and explanations, the type of gene mutation that involves the replacement of a purine with a pyrimidine or vice versa is called **transversion**.

### Final Answer:
The correct answer is **transversion**.

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