The standard eukaryotic cell cycle consists of four phases: G1, S, G2, and M phases. There are three phase transitions in a cell cycle: G1/S to initiate DNA synthesis, G2/M to enter mitosis ...
To maintain ploidy, unidirectional progression through the phases of the cell cycle (G1 → S → G2 → M → G1) is essential. To keep cells from regressing, the transitions of the mitotic cell ...