Recombination nodule is seen in stage

Options

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

Answer

**Step-by-Step Solution:**

1. **Understanding Recombination Nodules**: Recombination nodules are structures that form during meiosis and are associated with the process of genetic recombination. They play a crucial role in the exchange of genetic material between homologous chromosomes.

2. **Identifying Meiosis Stages**: Meiosis consists of several stages, particularly during prophase I, which includes leptotene, zygotene, pachytene, diplotene, and diakinesis. Each stage has distinct characteristics and processes.

3. **Analyzing Each Stage**:
- **Leptotene**: Chromosomes begin to condense, but no recombination nodules are formed yet.
- **Zygotene**: Homologous chromosomes start to pair up (synapsis), but recombination nodules are not fully formed.
- **Pachytene**: Tetrads (paired homologous chromosomes) are formed, and this is where crossing over begins, leading to the formation of recombination nodules.
- **Diplotene**: The tetrads start to separate, but the recombination nodules are still present as crossing over continues.
- **Diakinesis**: This is the final stage of prophase I where the chromosomes are fully condensed, and crossing over is completed. It is at this stage that recombination nodules are most evident.

4. **Conclusion**: Recombination nodules are primarily observed in the diakinesis stage of prophase I, as this is where the crossing over is finalized.

**Final Answer**: Recombination nodule is seen in the stage of **diakinesis**.

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