Movement of bivalents towards the periphery of the nucleus and their movement towards equator of the meiocyte occur respectively during

Options

A. Diakinesis and anaphase I
B. Diplotene and diakinesis
C. Leptotene and diakinesis
D. Diakinesis and metaphase

Answer

To solve the question regarding the movement of bivalents towards the periphery of the nucleus and their movement towards the equator of the meiocyte, we need to analyze the stages of meiosis, particularly during prophase I and metaphase I.

### Step-by-Step Solution:

1. **Understanding Meiosis**: Meiosis is a type of cell division that reduces the chromosome number by half and involves two successive divisions: meiosis I and meiosis II. The first division (meiosis I) includes several stages, particularly prophase I, which is further divided into sub-stages.

2. **Identifying the Stages of Prophase I**: Prophase I of meiosis consists of five sub-stages:
- Leptotene
- Zygotene
- Pachytene
- Diplotene
- Diakinesis

3. **Movement of Bivalents**:
- During **Diakinesis**, the bivalents (paired homologous chromosomes) prepare for separation. The nuclear membrane breaks down, and the chromosomes condense further. This is when the bivalents move towards the periphery of the nucleus.
- During **Metaphase I**, the bivalents align at the equatorial plane of the cell. This is the stage where they are positioned for separation.

4. **Conclusion**:
- The movement of bivalents towards the periphery of the nucleus occurs during **Diakinesis**.
- The movement of bivalents towards the equator of the meiocyte occurs during **Metaphase I**.

5. **Final Answer**: Therefore, the correct answer to the question is that the movement of bivalents towards the periphery of the nucleus occurs during **Diakinesis**, and their movement towards the equator of the meiocyte occurs during **Metaphase I**.

### Answer:
**Diakinesis and Metaphase I** (Option 4).

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