During meiosis spindle formation in initiated during

Options

A. Zygotene of Prophase-I
B. Pachytene of Prophase-I
C. Metaphase-I
D. Interphase

Answer

### Step-by-Step Solution:

1. **Understanding Meiosis**: Meiosis is a specialized type of cell division that reduces the chromosome number by half, resulting in the formation of four gametes. It is essential for sexual reproduction, producing sperm and egg cells.

2. **Phases of Meiosis**: Meiosis consists of two main stages: Meiosis I and Meiosis II. Each of these stages has several phases, including prophase, metaphase, anaphase, and telophase.

3. **Identifying the Relevant Phase**: The question asks during which phase spindle formation is initiated. In Meiosis I, spindle fiber formation occurs during the prophase stage.

4. **Prophase I Details**: Prophase I is further divided into several substages:
- Leptotene
- Zygotene
- Pachytene
- Diplotene
- Diakinesis

5. **Spindle Fiber Formation**: The initiation of spindle fiber formation occurs during the zygotene stage of prophase I. This is when homologous chromosomes begin to pair up and the spindle apparatus starts to form.

6. **Evaluating Other Options**:
- **Pachytene**: This stage is characterized by crossing over, not spindle formation.
- **Metaphase I**: Here, homologous chromosomes align at the equatorial plate, but spindle fibers are already formed.
- **Interphase**: This is the preparatory phase before meiosis begins, where the cell grows and duplicates its DNA, but spindle fibers do not form during this phase.

7. **Conclusion**: Therefore, the correct answer to the question is that spindle formation is initiated during the **zygotene stage of prophase I** in meiosis.

### Final Answer:
Spindle formation is initiated during the **zygotene stage of prophase I** in meiosis.

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