【单选题】The Cdk partner of cyclin B (M cyclin) is _____ in vertebrates, and the active complex it forms with its Cdk is called M-Cdk, acting in G 2 to trigger entry into M phase.
【单选题】The Cdk partner of cyclin E (G 1 /S cyclin) is _____ in vertebrates, and the active complex it forms with its Cdk is called G 1 /S-Cdk, regulating transition from G 1 to S phase.