Final answer:
The female gamete, or ovum, completes meiosis II when the secondary oocyte is fertilized by a sperm, leading to the formation of a mature egg and a polar body. Without fertilization, the secondary oocyte does not complete meiosis II and disintegrates.
Step-by-step explanation:
The female gamete, also known as the ovum, is not formed until meiosis II is completed, which occurs when A) the secondary oocyte has been fertilized by the sperm. At the point of fertilization, all secondary oocytes remain arrested in metaphase of meiosis II. It is only upon fertilization that the secondary oocyte rapidly completes meiosis II, resulting in the formation of a mature ovum and an additional polar body. If the secondary oocyte is not fertilized, it passes into the uterus as an immature egg and soon disintegrates without completing meiosis II.