Final answer:
Ovulation is the process when a mature follicle in the ovary releases a secondary oocyte, which can then be fertilized.
Step-by-step explanation:
The time at which a primary follicle is ready to shed an egg mature enough for fertilization from the ovary is called ovulation. During this process, after 12-14 days of maturation, the follicle bursts open, releasing the secondary oocyte from the ovary.
The follicle then transforms into a structure known as the corpus luteum, which begins to degenerate if fertilization does not occur. If fertilization does take place, the secondary oocyte quickly completes meiosis II and forms a diploid zygote, which will then continue its journey through the Fallopian tube towards the uterus for potential implantation.