Cell cycle is the series of events in which cells replicate and make two new cells. Cell cycle consists of stages- G1,S,G2, and M (karyokinesis). G1 is the stage where the cell is preparing to divide. It then moves into the S phase where the cell copies all the DNA. S stands for synthesis phase of DNA. Histone proteins are also synthesised during the phase. After the DNA is copied and there's a complete extra set of all the genetic material, the cell moves into the G2 stage, where it organizes and condenses the genetic material, or starts to condense the genetic material, and prepares to divide.