When are chromatids/chromosomes clearly visible in meiosis ?

Options

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

Answer

**Step-by-Step Text Solution:**

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

2. **Prophase I of Meiosis**: Prophase I is a lengthy phase in meiosis and is further divided into five sub-stages: leptotene, zygotene, pachytene, diplotene, and diakinesis.

3. **Chromosome Condensation**: Chromosomes begin to condense during prophase. This condensation makes the chromosomes more visible under a microscope.

4. **Stages of Prophase I**:
- **Leptotene**: Chromosomes start to condense but are not yet clearly visible.
- **Zygotene**: Homologous chromosomes begin to pair up, but they are still not clearly visible.
- **Pachytene**: Crossing over occurs, and chromosomes are still not fully distinct.
- **Diplotene**: This is the critical stage where the homologous chromosomes begin to separate but remain attached at points called chiasmata. At this stage, the chromosomes are clearly visible due to further condensation.
- **Diakinesis**: Chromosomes are fully condensed and visible, but the question specifically asks about when they are clearly visible during meiosis.

5. **Conclusion**: The chromatids or chromosomes are clearly visible during the **diplotene stage** of prophase I in meiosis.

**Final Answer**: Chromatids/chromosomes are clearly visible in the diplotene stage of meiosis.

---