The three subphases of interphase are alike in that there is constant cell development during each phase, and cell division does not occur. Each of the three stages finishes with a cellular checkpoint to ensure only cells without mutations are copied before proceeding to the next step.
The stages of interphase, known as the G1 phase, the S phase and the G2 phase, all actively prepare cells for division through physical growth and DNA duplication. During the G1 phase, or Gap 1, a cell doubles its original size in preparation for division into two daughter cells. The cell makes large amounts of protein necessary for DNA replication, and it forms additional organelles. The S phase, also known as Synthesis, is the period in which the cell duplicates its DNA, ensuring all of the chromosomes are replicated. In the G2 phase, or Gap 2, the cell resumes its growth with the integration of various proteins needed during mitosis.
Once a cell has completed all the stages of interphase, it moves into mitosis, during which period the cell divides to produce two genetically identical cells. The newly created cells can then return to the first step of interphase and repeat the cycle once again. This repetitive cycle of cell division is the method by which skin, hair and blood cells are renewed.