During which stage a diploid cell becomes tetraploid in mitosis:-

Options

A. `G_(2)`
B. Prophae
C. Metaphase
D. Anaphase

Answer

To determine during which stage a diploid cell becomes tetraploid in mitosis, we need to analyze the stages of the cell cycle and mitosis.

### Step-by-Step Solution:

1. **Understand the Cell Cycle**: The cell cycle consists of interphase (which includes G1, S, and G2 phases) and mitotic phase (which includes prophase, metaphase, anaphase, and telophase).

2. **Identify the Stages of Mitosis**: Mitosis is divided into several stages:
- **Prophase**: Chromatin condenses into chromosomes, and the nucleolus disappears.
- **Metaphase**: Chromosomes align at the cell's equatorial plane.
- **Anaphase**: Sister chromatids are pulled apart to opposite poles of the cell.
- **Telophase**: Chromosomes de-condense, and the nuclear envelope re-forms.

3. **Recognize the Role of the S Phase**: The S phase (synthesis phase) is where DNA replication occurs, resulting in the duplication of chromosomes. After this phase, each chromosome consists of two sister chromatids.

4. **Determine the Diploid to Tetraploid Transition**:
- A diploid cell (2n) contains two sets of chromosomes. After DNA replication in the S phase, it becomes tetraploid (4n) because it now has four sets of chromosomes (two sets of sister chromatids for each chromosome).
- However, the question specifically asks about mitosis. During mitosis, the cell is still considered diploid until the anaphase, where the sister chromatids separate.

5. **Conclusion**: The diploid cell effectively becomes tetraploid during the anaphase of mitosis when the duplicated chromosomes are separated, leading to a temporary state where the cell has four sets of chromosomes before cytokinesis occurs.

### Final Answer:
The diploid cell becomes tetraploid during the **anaphase** stage of mitosis.

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