In which of the following stages of cell division is the nuclear envelope of a dividing eukaryotic cell intact

Options

A. Interphase
B. Late prophase
C. Anaphase II
D. Metaphase I

Answer

To determine in which stage of cell division the nuclear envelope of a dividing eukaryotic cell is intact, we can analyze the stages of the cell cycle and the process of cell division.

### Step-by-Step Solution:

1. **Understand the Cell Cycle**: The cell cycle consists of interphase (G1, S, G2 phases) and the mitotic phase (M phase), which includes mitosis and cytokinesis.

2. **Identify Interphase**: Interphase is the stage where the cell prepares for division. It includes:
- **G1 Phase**: Cell growth
- **S Phase**: DNA replication
- **G2 Phase**: Preparation for mitosis

3. **Nuclear Envelope During Interphase**: During interphase, the nuclear envelope is intact. The cell is not actively dividing, and the genetic material is contained within the nucleus.

4. **M Phase and Prophase**: As the cell enters the M phase, specifically during prophase (both in mitosis and meiosis), the nuclear envelope begins to break down. This means that after prophase, the nuclear envelope is no longer intact.

5. **Analyze the Options**:
- **A. Interphase**: The nuclear envelope is intact.
- **B. Late Prophase**: The nuclear envelope is not intact.
- **C. Anaphase 2**: The nuclear envelope is not intact.
- **D. Metaphase 1**: The nuclear envelope is not intact.

6. **Conclusion**: The only stage where the nuclear envelope remains intact is during interphase.

### Final Answer:
The correct option is **A. Interphase**.

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