In which phase of cell cycle the amout of DNA in a diploid cell become four times as compared to a haploid cell?

Options

A. `G_(1)`
B. S
C. `G_(2)`, S & M
D. `G_(@)`

Answer

**Step-by-Step Solution:**

1. **Understanding Cell Cycle Phases**: The cell cycle consists of several phases: G1, S, G2, and M (mitotic phase). Each phase has specific functions related to cell growth and division.

2. **Identifying Diploid and Haploid Cells**: A diploid cell (2N) contains two sets of chromosomes, while a haploid cell (N) contains one set. For example, in humans, diploid cells have 46 chromosomes, while haploid cells have 23 chromosomes.

3. **Focus on the S Phase**: The S phase, or synthesis phase, is where DNA replication occurs. During this phase, each chromosome is duplicated, resulting in two sister chromatids for each chromosome.

4. **Calculating DNA Content**: In a diploid cell during the S phase:
- Before S phase: DNA content = 2N (diploid)
- After S phase: DNA content = 4N (since each chromosome is duplicated)
- Therefore, the DNA content becomes four times that of a haploid cell (N).

5. **Conclusion**: The phase of the cell cycle in which the amount of DNA in a diploid cell becomes four times that of a haploid cell is the S phase.

**Final Answer**: The S phase.

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