Fertilization: The process in which the spermatozoon penetrates into the ovum to form fertilized ovum In the ampulla of oviduct Ampulla site of fertilization (sperm cell penetrates oocyte) Uterine tube ocote rary Sperm cells deposited in vaginaFertilization: The process in which the spermatozoon penetrates into the ovum to form fertilized ovum. In the ampulla of oviduct