Optometry Admission Test (OAT) Practice

Which stage precedes the M phase in the cell cycle?

1. G1 phase

2. S phase

3. G2 phase

4. Interphase

The correct answer is: G2 phase

The M phase, or mitotic phase, is the stage in the cell cycle where cell division occurs, resulting in the formation of two daughter cells. The stage that directly precedes the M phase is the G2 phase. During the G2 phase, the cell has completed DNA replication (which occurs in the S phase) and is preparing for mitosis. In this phase, the cell undergoes further growth and produces proteins necessary for mitosis. It also performs a series of checks to ensure that the DNA has been accurately replicated and that the cell is ready to divide. If the cell is not ready, it can halt the cycle at this checkpoint to prevent errors in cell division. Understanding the order of the cell cycle is critical, as it highlights the transitions and processes that must occur for healthy cell division. The G2 phase is essential for a cell's preparation for M phase, which ensures that mitosis can occur efficiently and correctly.