Which of the following describe(s) cyclin-dependent kinase (Cdk)?
A) Cdk is inactive, or ʺturned off,ʺ in the presence of cyclin.
B) Cdk is present throughout the cell cycle.
C) Cdk is an enzyme that attaches phosphate groups to other proteins.
D) Both A and B are true.
E) Both B and C are true.
Answer: E