Cell-Cycle Checkpoints, Three Gates
This video presents the same text shown beside it, spoken and on screen. It adds nothing the text does not say.
State
A cell-cycle checkpoint is an internal control point halting progress until required conditions are met, with major checkpoints at the end of G1, at the G2-to-mitosis transition, and during metaphase.
Show
A cell with unrepaired DNA damage can be held indefinitely at one checkpoint rather than proceeding.
Watch for
These checkpoints are internal gates, distinct from the external growth-factor signals that trigger the cycle.