Rearrangement of genes occurs due to

Options

A. Transloction and duplication
B. Translocation and deficiency
C. Deletion and deficiency
D. Translocation and inversion

Answer

**Step-by-Step Solution:**

1. **Understanding Gene Rearrangement:**
Gene rearrangement refers to the alteration of the structure of chromosomes, which can affect the arrangement of genes. This can lead to changes in gene expression and can have various biological consequences.

2. **Identifying Causes of Gene Rearrangement:**
The question asks for the causes of gene rearrangement. The main processes that can lead to rearrangement include:
- **Translocation:** This is when a segment of one chromosome breaks off and attaches to another chromosome. It can involve two different chromosomes exchanging segments (reciprocal translocation) or one chromosome attaching to another (Robertsonian translocation).
- **Inversion:** This occurs when a segment of a chromosome breaks off and reattaches in the reverse orientation. This rearrangement happens within a single chromosome.

3. **Evaluating the Options:**
The options provided are:
- Translocation and duplication
- Translocation and deficiency
- Deletion and deficiency
- Translocation and inversion

- **Translocation and Duplication:** Duplication involves copying genes, which does not rearrange them.
- **Translocation and Deficiency:** Deficiency refers to the loss of genetic material, which does not rearrange genes.
- **Deletion and Deficiency:** Both deletion and deficiency refer to the loss of genes, not their rearrangement.
- **Translocation and Inversion:** Both processes involve rearranging the structure of chromosomes.

4. **Conclusion:**
The correct answer is **translocation and inversion** as both processes lead to the rearrangement of genes.

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