The eukaryotic cell cycle is divided into G1, S, G2, and
Chromosomal DNA replication takes place during S phase, whereas cell division (mitosis and cytokinesis) occurs in M phase.
Interphase (G1, S, and G2) is a time of cell growth and metabolism that typically occupies about 95% of the cycle.
G1 - Metabolic changes prepare the cell for division, all cellular components, excluding the chromosomes are duplicated. At a certain point, known as the restriction point (G0), the cell is committed to division and moves into the S phase.
S - DNA synthesis replicates the genetic material. Each chromosome now consists of two sister chromatids. --> 46 x 2 chromosomes now in cell.
G2 - Metabolic changes assemble the cytoplasmic materials necessary for Mitosis and cytokinesis, the cell also double checks the duplicated chromosomes for error, many any needed repairs.
The length of the cell cycle varies greatly, ranging from cells that divide rapidly and continuously to cells that do not divide at all.