Mechanisms Biological mechanism. (1)Cell cycle: a) Gap 1(G phase). b) DNA Synthesis(S phase). c)Gap2(G2 phase). d) Mitosis (M phase). Go is a resting phase in which the cells are not proliferinMechanisms: • Biological mechanism: • (1) Cell cycle: • a) Gap 1 (G1 phase). b) DNA synthesis (S phase). c) Gap 2 (G2 phase). d) Mitosis (M phase). G0 is a resting phase in which the cells are not prolifering