Chiasmata are formed during

Options

A. Leptotene
B. Zygotene
C. Pachytene
D. Diplotene

Answer

**Step-by-Step Solution:**

1. **Understanding Chiasmata**: Chiasmata are points where two homologous non-sister chromatids exchange genetic material during meiosis. This process is crucial for genetic diversity.

2. **Identifying the Stages of Meiosis**: Meiosis consists of several stages, particularly in prophase I, which includes:
- Leptotene
- Zygotene
- Pachytene
- Diplotene

3. **Analyzing Each Stage**:
- **Leptotene**: This is the first stage of prophase I where chromosomes begin to condense and become visible as thin threads. No chiasmata are formed here.
- **Zygotene**: In this stage, homologous chromosomes begin to pair up, a process known as synapsis. However, chiasmata formation has not yet occurred.
- **Pachytene**: This is the stage where the actual crossing over of genetic material occurs between non-sister chromatids. While crossing over happens here, the chiasmata are not yet fully formed.
- **Diplotene**: In this stage, the homologous chromosomes begin to separate but remain connected at the chiasmata, which are now visible. This is where chiasmata are fully formed and can be observed.

4. **Conclusion**: Based on the analysis of the stages, chiasmata are formed during the **Diplotene** stage of prophase I in meiosis.

5. **Final Answer**: Chiasmata are formed during **Diplotene**.

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