what is the purpose of the synthesis (s) phase of the cell cycle
What Phases Make Up the Eukaryotic Cell Cycle? In eukaryotes, the cell cycle consists of four discrete phases: G1, S, G2, and M. The S or synthesis phase is when DNA replication occurs, and the M or mitosis phase is when the cell actually divides. The other two phases â G1 and G2, the so-called gap phases â are less dramatic but equally important.