Synaptionemal complex first appear :-

Options

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

Answer

To determine when the synaptonemal complex first appears during meiosis, we can analyze the stages of prophase I, which are leptotene, zygotene, pachytene, and diplotene.

### Step-by-Step Solution:

1. **Understanding Meiosis Stages**: Meiosis consists of several stages, particularly during prophase I, which is divided into several sub-stages: leptotene, zygotene, pachytene, and diplotene.

2. **Leptotene Stage**: In the leptotene stage, chromosomes begin to condense and become visible, but homologous chromosomes have not yet paired up.

3. **Zygotene Stage**: The synaptonemal complex first appears during the zygotene stage. This is when homologous chromosomes start to pair up, a process known as synapsis. The synaptonemal complex facilitates this pairing by forming a structure that holds the homologous chromosomes together.

4. **Pachytene Stage**: Following zygotene, in the pachytene stage, the chromosomes are fully paired, and crossing over occurs. However, the synaptonemal complex is already present from the zygotene stage.

5. **Diplotene Stage**: In the diplotene stage, the synaptonemal complex begins to disassemble, and the homologous chromosomes start to separate slightly.

6. **Conclusion**: Therefore, the synaptonemal complex first appears during the zygotene stage of prophase I in meiosis.

### Final Answer:
The synaptonemal complex first appears during the **zygotene** stage of meiosis.

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