Human fertilization is defined as the union between a sperm and an egg, which marks the beginning of a new life and the basis of human reproduction. The result of fertilization is the production of a zygote cell, a cell which genome is formed of a combination of both the sperm's and the egg's genome. As could be noted, the term "fertilization" is closely related with the terms "sperm", "egg" and "zygote". Therefore, "fertilization" is the term that best completes the set.
