Which of the Following Triggers the Cell's Passage Past the G₂

Question

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

Accepted Answer

The cell's passage past the G₂ checkpoint into mitosis is triggered by MPF (Mitosis-promoting factor), which is a complex of cyclin and Cdk (cyclin-dependent kinase). Cyclin levels increase during G₂ phase, forming a complex with Cdk, and activating it to form MPF. MPF triggers the cell's entry into mitosis. Therefore, option B is the best choice.