Select the CORRECT option, for a somatic cell with 2n = 4.

Options

A. `{:(,"No. of chromatids","No. of chromosomes"),(G_1,2,4):}`
B. `{:(,"No.of chromatids","No. of chromosomes"),(G_2,4,4):}`
C. `{:(,"No.of chromatids","No. of chromosomes"),("Prophase",8,4):}`
D. `{:(,"No.of chromatids","No. of chromosomes"),("Metaphase",4,8):}`

Answer

To solve the question regarding a somatic cell with 2n = 4, we need to analyze the different phases of the cell cycle and how the number of chromatids and chromosomes changes throughout these phases.

### Step-by-Step Solution:

1. **Understanding 2n = 4**:
- The notation 2n = 4 indicates that the somatic cell has a diploid number of chromosomes, meaning there are 4 chromosomes in total.

2. **G1 Phase**:
- In the G1 phase, the cell has not yet replicated its DNA. Therefore:
- Number of chromosomes = 4 (since 2n = 4)
- Number of chromatids = 4 (each chromosome consists of a single chromatid at this stage).

3. **S Phase**:
- During the S phase, DNA replication occurs. Each chromosome is duplicated, leading to:
- Number of chromosomes = 4 (remains the same)
- Number of chromatids = 8 (each of the 4 chromosomes is now made up of 2 sister chromatids).

4. **G2 Phase**:
- After DNA replication, in the G2 phase:
- Number of chromosomes = 4 (still remains the same)
- Number of chromatids = 8 (as a result of the previous DNA replication).

5. **Prophase**:
- In prophase, the cell is preparing for mitosis:
- Number of chromosomes = 4 (still remains the same)
- Number of chromatids = 8 (still remains the same).

6. **Metaphase**:
- During metaphase, the chromosomes align at the metaphase plate:
- Number of chromosomes = 4 (still remains the same)
- Number of chromatids = 8 (still remains the same).

### Conclusion:
Based on the analysis, the correct option is:
- **Option 3**: Number of chromatids in prophase is 8, and the number of chromosomes is 4.