A cyclin ________.
A) is present in similar concentrations throughout the cell cycle
B) is activated by binding to microtubules
C) decreases in concentration when MPF activity increases
D) activates a Cdk molecule when it is in sufficient concentration
E) activates a Cdk molecule when its concentration is decreased

Question

Quizplus · Accepted Answer

Cyclins activate a Cdk molecule when it is in sufficient concentration, leading to the formation of an active cyclin-Cdk complex that triggers various events in the cell cycle. The concentration of cyclins varies throughout the cell cycle, and different cyclins are present during different stages of the cycle. The activity of the cyclin-Cdk complex is regulated by various mechanisms, including the availability of cyclins and phosphorylation.

A Cyclin ________