The cell must also pass through a series of checkpoints that ensure conditions are favorable for division. In order to move from one phase of its life cycle to the next, a cell must pass through ...

To accomplish this challenging feat, origins of replication are prepared for 'firing' exclusively in the G1 phase of the cell cycle. After S phase is complete, replication origins do not fire ...

In the "proanagen phase," the follicle makes cells that will form the hair ... The telogen stage of the hair cycle is a resting phase, during which the hair doesn't grow, and the follicle is ...