Which one of the following is incorrect?

Options

A. `G_(1)` Phase corresponds to interval between mitosis and initiation of DNA replication
B. During `G_(1)`, Phase the cell is metabolically inactive
C. DNA replication takes place during S- phase
D. If the cell had diploid or 2n number of chromosome at `G_(1)` , even after S-phase the number of chromosomes remain the same i.e. 2n

Answer

To determine which statement is incorrect, we will analyze each option provided in the question step by step.

### Step 1: Analyze the first statement
**Statement:** G1 phase corresponds to the interval between mitosis and the initiation of DNA replication.

- **Analysis:** This statement is correct. The G1 phase (Gap 1) is indeed the phase that occurs after mitosis (M phase) and before the S phase, where DNA replication begins.

### Step 2: Analyze the second statement
**Statement:** During G1 phase, the cell is metabolically inactive.

- **Analysis:** This statement is incorrect. During the G1 phase, the cell is metabolically active. It is a time for growth and preparation for DNA synthesis, where RNA and proteins are synthesized.

### Step 3: Analyze the third statement
**Statement:** DNA replication takes place during the S phase.

- **Analysis:** This statement is correct. The S phase (Synthesis phase) is specifically when DNA replication occurs.

### Step 4: Analyze the fourth statement
**Statement:** If the cell has diploid or the twin number of chromosomes at G1, even after S phase, the number of chromosomes remains the same.

- **Analysis:** This statement is correct. Although the amount of DNA doubles during the S phase, the number of chromosomes remains the same because each chromosome is replicated into two sister chromatids, which are still counted as a single chromosome until they are separated during mitosis.

### Conclusion
After analyzing all statements, the incorrect statement is the second one: "During G1 phase, the cell is metabolically inactive."

### Final Answer
The incorrect statement is: **Option 2: During G1 phase, the cell is metabolically inactive.**

---