If the cell had diploid or 2n number of chromosomes at `G_(1)` then
after S-phase the number of chromosomes will be_____

Answer

To solve the question regarding the number of chromosomes after the S-phase, we can break it down into the following steps:

### Step-by-Step Solution:

1. **Understanding the Cell Cycle**:
- The cell cycle consists of several phases, including G1 (Gap 1), S (Synthesis), and G2 (Gap 2).

2. **Identifying the Starting Point**:
- In the G1 phase, the cell has a diploid number of chromosomes, denoted as 2n. This means that there are two sets of chromosomes, one from each parent.

3. **What Happens During the S Phase**:
- The S phase is characterized by DNA replication. During this phase, each chromosome is replicated, resulting in two identical sister chromatids for each chromosome.

4. **Determining the Number of Chromosomes**:
- Although the amount of DNA in the cell doubles (because each chromosome is replicated), the actual number of chromosomes remains the same.
- Thus, if the cell started with 2n chromosomes in G1, it will still have 2n chromosomes after the S phase.

5. **Conclusion**:
- Therefore, after the S phase, the number of chromosomes in the cell will still be 2n.

### Final Answer:
The number of chromosomes after the S phase will be **2n**.

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