Which one is the longest phase?

Options

A. `G_(1)`
B. Metaphase
C. lnterphase
D. Prophase

Answer

To determine which phase of the cell cycle is the longest, we can analyze the different phases involved in the cell cycle:

1. **Identify the phases of the cell cycle**: The cell cycle consists of several phases:
- G1 phase (Gap 1)
- S phase (Synthesis)
- G2 phase (Gap 2)
- M phase (Mitosis)

2. **Understand the duration of each phase**:
- G1 phase: This is the first gap phase where the cell grows and prepares for DNA replication. It lasts approximately 7 hours.
- S phase: This is the synthesis phase where DNA replication occurs. It lasts approximately 4 hours.
- G2 phase: This is the second gap phase where the cell prepares for mitosis. Its duration is not specified in the transcript, but it is generally shorter than G1.
- M phase: This is the mitotic phase where the cell divides. It is the shortest phase and lasts for about 1 hour.

3. **Calculate the total time spent in interphase**: Interphase includes G1, S, and G2 phases. Since G1 lasts about 7 hours, S lasts about 4 hours, and G2 is shorter than G1, we can conclude that interphase (G1 + S + G2) takes the majority of the cell cycle time.

4. **Conclusion**: Since interphase (G1 + S + G2) takes up approximately 95% of the total time of the cell cycle, it is the longest phase. Therefore, the longest phase in the cell cycle is interphase.

### Final Answer:
The longest phase of the cell cycle is interphase.