Interphase is the stage of the cell cycle that usually lasts the longest. During interphase, the cell may not look like it is doing much, but many significant events are happening to prepare it for cell division.
Three subphases make up interphase.The cell grows during the G1, or first gap, phase. In a special type of G1 phase, sometimes called a G0 phase, cells such as nerve cells never leave the first gap phase. The G1 subphase takes up the most time in the whole cell cycle. In the S, or synthesis, phase, chromosomes are duplicated. During this time, proteins associated with DNA also replicate to form new chromosomes. The G2, or second gap, phase sees more cell growth.