Chiasmata are most clearly visualised in which stage?

Options

A. Diakinesis
B. Diplotene
C. Metaphase II
D. Pachytene

Answer

To solve the question regarding the stage in which chiasmata are most clearly visualized, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Chiasmata**:
- Chiasmata are points of contact between non-sister chromatids of homologous chromosomes. They represent the physical exchange of genetic material during meiosis.

2. **Identify the Stages of Meiosis**:
- Meiosis consists of several stages, particularly during Prophase I, which includes:
- Leptotene
- Zygotene
- Pachytene
- Diplotene
- Diakinesis

3. **Analyze Each Option**:
- **Option A: Dichinesis**: This is not a recognized stage in the context of chiasmata visibility.
- **Option B: Diplotin**: This is a misspelling of "Diplotene," which is a stage in Prophase I where chiasmata become visible.
- **Option C: Metaphase II**: Chiasmata are not typically visible during this stage as the chromosomes are aligned at the metaphase plate.
- **Option D: Pachytene**: While chiasmata may begin to form during this stage, they are not as clearly visible as in Diplotene.

4. **Conclusion**:
- The stage where chiasmata are most clearly visualized is **Diplotene**, which is part of Prophase I of meiosis.

### Final Answer:
- **Option B: Diplotin (Diplotene)** is the correct answer.