
The secondary follicle becomes larger, turning into a mature( Graafian) follicle.
While in the mature follicle just before ovulation, the diploid primary oocyte completes meiosis I and produces two haploid (n) cells, of unequal size.
The larger cell is called the secondary oocyte and the smaller one is called the first polar body, a packet of discarded nuclear material.
The larger cell that is a secondary oocyte, begins its meiosis II but then stops at metaphase.
The mature( Graafian ) follicle ruptures and releases its secondary oocyte, by a process known as ovulation.