The cell cycle is the ordered sequence describing a cell's lifespan, partitioned into two overarching states: interphase, in which the cell grows without dividing and where cells spend most of their existence, and mitosis (M), the period of active cell division. Interphase itself resolves into three ordered subphases — G1, the longest phase, devoted to growth and to production of organelles, ribosomes, and proteins; S phase, defined by DNA synthesis (chromosome replication); and G2, a second growth phase dedicated to direct preparation for division, including synthesis of the microtubules that later separate chromatids. A regulatory branch point at G1 allows exit into G0, a non-dividing state occupied by terminally differentiated cell types. The concept belongs to cell biology and situates division within a cyclic framework: daughter cells re-enter G1, and dysregulation of the balance between growth and division characterizes cancer.
The cell cycle is the ordered sequence describing a cell's lifespan, partitioned into two overarching states: interphase, in which the cell grows without dividing and where cells spend most of their …