From which phase of the cell cycle does a cell enter the G0 phase?

• A. G2 phase
• B. S phase
• C. G1 phase
• D. M phase

Answer: (C)

Verified step by step guidance

1. Understand the cell cycle: The cell cycle consists of several phases, including G1, S, G2, and M phases. Each phase has specific functions in cell growth and division.
2. Identify the G0 phase: The G0 phase is a resting or quiescent stage where cells exit the active cell cycle and do not actively prepare to divide. Cells in G0 are often differentiated and perform their specific functions.
3. Determine the transition point: Cells typically enter the G0 phase from the G1 phase. This transition occurs when cells do not receive the necessary signals to proceed to the S phase, where DNA replication occurs.
4. Consider the role of checkpoints: During the G1 phase, cells assess whether conditions are favorable for division. If conditions are not met, cells may enter the G0 phase instead of continuing to the S phase.
5. Conclude the entry point: Based on the understanding of the cell cycle and checkpoints, the G1 phase is the point from which cells can enter the G0 phase if they do not proceed to DNA synthesis in the S phase.