[Campbell Biology P.295] Which of the following sequences correctly describes the molecular ... | Practice Question

Which of the following sequences correctly describes the molecular events involving cyclin and MPF during the cell cycle, as depicted in Figure 12.16b?

  • A: Cyclin synthesis → MPF degradation → Cyclin-Cdk complex formation → MPF promotes mitosis.
  • B: Cyclin-Cdk complex formation → Cyclin accumulation → MPF promotes mitosis → MPF degradation.
  • C: Cyclin accumulation → Cyclin combines with Cdk to form MPF → MPF activity peaks and promotes mitosis → Cyclin degradation and Cdk recycling.
  • D: MPF promotes mitosis → Cyclin degradation → Cyclin synthesis → Cyclin-Cdk complex formation.

Explanation

Figure 12.16b outlines the cyclical regulation of the cell cycle by MPF. The correct sequence starts with cyclin accumulation step 1 , followed by its combination with Cdk to form MPF step 2 . MPF then promotes mitosis, peaking in activity step 3 . Finally, cyclin is degraded, and Cdk is recycled steps 4 and 5 , preparing the cell for the next cycle.