Chromosomes are first visible under light microscope during

Options

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

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks when chromosomes first become visible under a light microscope during the process of meiosis.

2. **Meiosis Overview**: Meiosis is a type of cell division that reduces the chromosome number by half, resulting in the production of gametes. It consists of two main stages: Meiosis I and Meiosis II.

3. **Stages of Meiosis I**: Meiosis I is further divided into four phases: Prophase I, Metaphase I, Anaphase I, and Telophase I. Prophase I is the longest phase of meiosis.

4. **Substages of Prophase I**: Prophase I is divided into five substages:
- Leptotene (or leptotin)
- Zygotene (or zygotin)
- Pachytene (or pachytin)
- Diplotene (or diplotin)
- Diakinesis

5. **Visibility of Chromosomes**: During the leptotene stage, chromosomes begin to condense and become visible under a light microscope. This is the first stage where they can be observed.

6. **Conclusion**: Since the question specifically asks for the stage where chromosomes are first visible, the correct answer is **Leptotene**.

**Final Answer**: Chromosomes are first visible under a light microscope during **Leptotene**.

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