AP BIOLOGY

Detailed explanation-1: -In order to drive the cell cycle forward, a cyclin must activate or inactivate many target proteins inside of the cell. Cyclins drive the events of the cell cycle by partnering with a family of enzymes called the cyclin-dependent kinases (Cdks).

Detailed explanation-2: -The central components of the cell-cycle control system are cyclin-dependent protein kinases (Cdks), whose activity depends on association with regulatory subunits called cyclins. Oscillations in the activities of various cyclin-Cdk complexes leads to the initiation of various cell-cycle events.

Detailed explanation-3: -The cell cycle has checkpoints (also called restriction points), which allow certain genes to check for problems and halt the cycle for repairs if something goes wrong. If a cell has an error in its DNA that cannot be repaired, it may undergo self-destruction (apoptosis ).

Detailed explanation-4: -Two groups of proteins, called cyclins and cyclin-dependent kinases (Cdks), are responsible for the progress of the cell through the various checkpoints.