Pairing of homologous chromosomes takes place in

Options

A. Pachytene
B. Zygotene
C. Diplotene
D. None of these

Answer

To answer the question "Pairing of homologous chromosomes takes place in," we need to analyze the stages of meiosis, specifically focusing on prophase I.

### Step-by-Step Solution:

1. **Understanding Meiosis**: Meiosis is a type of cell division that reduces the chromosome number by half, resulting in four haploid cells. It consists of two successive divisions: meiosis I and meiosis II.

2. **Prophase I of Meiosis**: Prophase I is the first stage of meiosis I and is longer and more complex than prophase in mitosis. It is divided into several phases: leptotene, zygotene, pachytene, diplotene, and diakinesis.

3. **Identifying the Phases**:
- **Leptotene**: The chromosomes start to condense and become visible.
- **Zygotene**: This is the phase where homologous chromosomes begin to pair up. This process is known as synapsis.
- **Pachytene**: The paired chromosomes become thicker and more condensed.
- **Diplotene**: The homologous chromosomes start to separate slightly but remain attached at points called chiasmata.
- **Diakinesis**: The chromosomes condense further and prepare for metaphase.

4. **Conclusion**: The pairing of homologous chromosomes occurs specifically during the **zygotene phase** of prophase I in meiosis. Therefore, the correct answer to the question is **zygotene**.

### Final Answer:
The pairing of homologous chromosomes takes place in **zygotene**.

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