Which of the following molecules triggers the cell's passage past the G₂ checkpoint into mitosis?
A) PDGF
B) MPF
C) cyclin
D) Cdk

Question

Quizplus · Accepted Answer

MPF (or maturation-promoting factor) is a complex of cyclin and Cdk (cyclin-dependent kinase) that triggers the cell's passage past the G₂ checkpoint into mitosis. Cyclin levels rise during the cell cycle and peak during the G₂ phase, leading to the formation of MPF. Once activated, MPF initiates a series of events that result in chromosome condensation, spindle formation, and nuclear envelope breakdown, leading to entry into the M phase of the cell cycle. PDGF (platelet-derived growth factor) is a growth factor that stimulates cell division but does not specifically trigger the passage past the G₂ checkpoint.

Which of the Following Molecules Triggers the Cell's Passage Past