Which of the Following Statements Concerning Cyclin-Dependent Protein Kinases Is

Multiple Choice

Which of the following statements concerning cyclin-dependent protein kinases is not correct?

A) Each type of cell contains one specific form (isozyme) .
B) Their activity fluctuates during the cell cycle.
C) Their activity is regulated by changes in gene expression,protein phosphorylation,and proteolysis.
D) Their activity is regulated by cyclins.
E) They can alter the activity of proteins involved in the progression of cells through the cell cycle.