Question

Studies with Xenopus eggs identified a partly purified activity called maturation promoting factor (MPF) that drives a resting Xenopus oocyte into M phase. MPF activity was found to be oscillate during the cell cycle, although the amount of its kinase component, called ____, remained constant.

a. APC
b. Cyclin
c. Ubiquitin
d. Cdk

Answer 1

In studies with Xenopus eggs, the constant kinase component of maturation promoting factor (MPF) is known as cdk or cyclin-dependent kinase, which works in conjunction with the oscillating levels of cyclin to drive the cell cycle.

Step-by-step explanation:

Studies with Xenopus eggs identified an activity known as maturation promoting factor (MPF) that initiates the M phase in a Xenopus oocyte. MPF's activity oscillates during the cell cycle. The kinase component of MPF, which is the focus of this question, remains constant in amount throughout the cycle. This kinase component is cdk, or cyclin-dependent kinase. Although the levels of cdk stay constant, the regulatory subunit of MPF, known as cyclin, varies in concentration during the cell cycle, thus affecting MPF activity.