Flexi Says: Most of the cell cycle consists of interphase, the time between cell divisions. Interphase can be divided into three stages: The first growth phase (G1): During the G1 stage, the cell doubles in size and doubles the number of organelles. The synthesis phase (S): The DNA is replicated during this phase. In other words, an identical copy of all the cell’s DNA is made. This ensures that each new cell has a set of genetic material identical to that of the parental cell. This process is called DNA replication. The second growth phase (G2): Proteins are synthesized that will help the cell divide. At the end of interphase, the cell is ready to enter mitosis. During mitosis, the nucleus divides as the chromosomes are equally separated. One nucleus becomes two nuclei, each with an identical set of chromosomes. Mitosis is followed by cytokinesis, when the cytoplasm divides, resulting in two cells. After cytokinesis, cell division is complete.