Cyclin dependent kinases which control progression through cell cycle checkpoints are totally activated by which of the following?

Binding to cyclin, plus phosphorylation by a Cdk activating protein kinase

Phosphorylation by Cdk activating protein kinase

Phosphorylation by a tyrosine kinase

Cyclin dependent kinases which control progression through cell cycle

1.	Cyclin dependent kinases which control progression through cell cycle checkpoints are totally activated by which of the following?
A.	Binding to cyclin, plus phosphorylation by a Cdk activating protein kinase
B.	Binding to cyclins
C.	Phosphorylation by Cdk activating protein kinase
D.	Phosphorylation by a tyrosine kinase
Answer» B. Binding to cyclins