And this happens before the birth of that female individual. So once that female individual is born, all these stem cells have become the primary oocytes. And these primary oocytes are frozen. They remain in ProPhase one of meiosis until puberty is reached. And when that female individual reaches puberty, she begins the process known as the menstrual cycle. And what the menstrual cycle describes is it describes the process by which the primary ocy eventually develops into that X cell, that single ovum that can be fertilized by the sperm cell to produce the zygote.