Regulation of the Cell Cycle Is Dependent on Cyclins and Cyclin-Dependent

Multiple Choice

Regulation of the cell cycle is dependent on cyclins and cyclin-dependent kinases.The key that allows a cell to progress beyond the restriction point is

A) the presence of cyclin.
B) the absence of cyclin.
C) the presence of cyclin and Cdk.
D) phosphorylation of RB by Cdk.
E) the presence of external signals from growth factors.