Identify the one, which causes gene mutation

Options

A. Granoson
B. Colchicine
C. Crossing over
D. X-rays

Answer

To identify which option causes gene mutation, we will analyze each option provided in the question.

### Step-by-Step Solution:

1. **Understanding Gene Mutation**:
- Gene mutation refers to a change in the nucleotide sequence of DNA. This change can lead to alterations in the function of genes and can be caused by various agents known as mutagens.

2. **Identifying the Options**:
- The options provided are:
- A) Granosone
- B) Colchicine
- C) Crossing Over
- D) X-rays

3. **Evaluating Option A: Granosone**:
- Granosone is not recognized as a mutagen. It does not have any known role in causing mutations. Therefore, this option is incorrect.

4. **Evaluating Option B: Colchicine**:
- Colchicine is a chemical that inhibits the formation of the mitotic spindle during cell division. While it affects cell division, it does not induce mutations in the DNA sequence. Thus, this option is also incorrect.

5. **Evaluating Option C: Crossing Over**:
- Crossing over is a natural process that occurs during meiosis where homologous chromosomes exchange genetic material. This process is essential for genetic diversity but does not cause mutations. Therefore, this option is incorrect as well.

6. **Evaluating Option D: X-rays**:
- X-rays are a form of high-energy ionizing radiation. Exposure to X-rays can cause ionization of atoms in the DNA, leading to mutations. This makes X-rays a known mutagen. Therefore, this option is correct.

### Conclusion:
- The correct answer to the question "Identify the one which causes gene mutation" is **D) X-rays**.