The carpel of a flower has an ovary at the base of its long slender style. Within this ovary are one or more ovules (depending on the species of flower). There may even be several carpels, each housing an ovary. The ovary is where plant fertilization takes place after pollination. When a pollen grain lands on the stigma, it travels to the ovule, which consists of an embryonic sac. When egg and sperm combine DNA, the result is an endosperm nucleus enclosed within a zygote that develops into another plant. The flower ovary is an organ essential to the embryological development of the angiosperm.