cell cycle

Ordered sequence of events in which a cell duplicates its chromosomes and divides into two. Most eukaryotic cell cycles can be commonly divided into four phases: G1 before DNA synthesis occurs; S when DNA replication occurs; G2 after DNA synthesis; and M when cell division occurs, yielding two daughter cells. Under certain conditions, cells exit the cell cycle during G1 and remain in the G0 state as nongrowing, nondividing (quiescent) cells. Appropriate stimulation of such cells induces them to return to G1 and resume growth and division. (Figure 13-1)

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