The nuclear membrane disappears in

Options

A. metaphase
B. anaphase
C. early prophase
D. late prophase

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks in which phase of cell division the nuclear membrane disappears.

2. **Identifying the Phases of Mitosis**: Mitosis consists of several stages: prophase, metaphase, anaphase, and telophase. Each of these stages has distinct events.

3. **Focusing on Prophase**: Prophase is the first stage of mitosis. It can be further divided into early prophase, middle prophase, and late prophase.

4. **Events in Prophase**:
- **Early Prophase**: Chromosomes begin to condense.
- **Middle Prophase**: Sister chromatids are attached to the centromere.
- **Late Prophase**: This is the critical stage where the nuclear membrane begins to break down.

5. **Identifying Late Prophase**: In late prophase (also referred to as pro-metaphase), the nuclear envelope disintegrates, leading to the disappearance of the nuclear membrane. The nucleoli also degenerate during this phase.

6. **Conclusion**: The nuclear membrane disappears in the late prophase of mitosis. Therefore, the correct answer is option 4: late prophase.

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