Nucleolus and nuclear membrane disappears in

Options

A. Anaphase
B. Interphase
C. Telophase
D. Prophase

Answer

**Step-by-Step Solution:**

1. **Understanding the Question:**
The question asks when the nucleolus and nuclear membrane disappear during cell division. This is a key event in the process of mitosis and meiosis.

2. **Identifying the Phases of Cell Division:**
The main phases of cell division include:
- Interphase
- Prophase
- Metaphase
- Anaphase
- Telophase

3. **Analyzing Each Phase:**
- **Interphase:** This is the phase where the cell prepares for division. The nucleolus and nuclear membrane are present.
- **Prophase:** This is the phase where chromatin condenses into chromosomes. The nucleolus begins to disappear, and the nuclear membrane starts to break down.
- **Metaphase:** The chromosomes align at the cell's equatorial plane. The nucleolus and nuclear membrane are still absent.
- **Anaphase:** The sister chromatids are pulled apart to opposite poles. The nucleolus and nuclear membrane remain absent.
- **Telophase:** The chromosomes reach the poles and begin to de-condense. The nuclear membrane re-forms, and the nucleolus reappears.

4. **Focusing on Prophase:**
During prophase, specifically in the stage known as dikinesis (the final stage of prophase in meiosis), the nucleolus and nuclear membrane completely disappear. This is crucial for the subsequent stages of cell division.

5. **Conclusion:**
The nucleolus and nuclear membrane disappear during **prophase**, particularly in the dikinesis stage of meiosis.

**Final Answer:** The nucleolus and nuclear membrane disappear in **prophase**.

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