Cleavage of zygote: cell resulting from fertilization. In dividing, the egg becomes a new being.
Ovum: female reproductive cell.
Two cells: part of its intrauterine growth when the ovule consists of two cells.
Four cells: part of its intrauterine growth when the ovule consists of four cells.
Eight cells: part of its intrauterine growth when the ovule consists of eight cells.
Blastomere stage (mass of cells): part of its intrauterine growth when the ovule consists of more than eight cells.
Blastocyst: part of the development of the egg where the dividing cells form a sac.
Amniotyc cavity: pocket filled with amniotic fluid.
Embryonic disk: round, flat form related to the embryo.
Connecting stalk: tissue that holds the embryo in place.
Embryo: organism in midst of development.
Chrionic villi: velvety surface of the placenta.
Yolk sac: pocket containing the vitellus.
Umbilical cord: cord connecting the fetus to the placenta.
Allantois: one of three accessory parts of the embryo.
Heart: blood-pumping organ.
Digestive tract developing: the beginning of the development of the digestive tract.
Anterior disgestive tube: terminal part of the cloaqua.
Chorion: external embryonic menbrane.