Final answer:
The activity that drives a resting Xenopus oocyte into M phase is called Maturation Promoting Factor (MPF).
Step-by-step explanation:
The partly purified activity in Xenopus eggs that drives a resting Xenopus oocyte into M phase is called Maturation Promoting Factor (MPF). MPF is a protein kinase made up of two polypeptide subunits. It can be isolated from mid-meiotic cells and injected into pre-meiotic cells to induce meiosis.