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

To determine in which phase of the cell cycle the amount of DNA in a diploid cell becomes four times that of a haploid cell, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Terms**:
- A **haploid cell** (n) contains one set of chromosomes.
- A **diploid cell** (2n) contains two sets of chromosomes.

2. **Identify the DNA Replication Phase**:
- The cell cycle consists of several phases: G1, S, G2, and M.
- The **S phase** (Synthesis phase) is where DNA replication occurs. During this phase, each chromosome is duplicated.

3. **Calculate the DNA Amount**:
- In a diploid cell (2n), before the S phase, the amount of DNA is 2n.
- After the S phase, each chromosome is replicated, resulting in 4n (two copies of each of the two sets of chromosomes).

4. **Compare with Haploid Cell**:
- A haploid cell has n amount of DNA.
- Therefore, in a diploid cell after the S phase, the amount of DNA (4n) is four times that of a haploid cell (n).

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

### Final Answer:
The answer is **S phase**.