Yolk sac

The fattier egg yolk is contained in the yolk sac.

Yolk

The egg yolk supplies the embryo with energy and nutrients.

Shell

The shell protects the developing embryo and allows water retention while still being permeable to gas exchange.

Amniotic fluid

The Amniotic fluid helps provide the embryo with a stable fluid environment.

Allantois

The membrane in an egg that stores nitrogenous wastes produced by the embryo and facilitates respiration.

Amnion

The innermost membrane of the fetal membranes of amniotes, the sac in which the embryo is suspended, protects the embryo from shock and carries out hydration.

Chorion

The chorion allows the exchange of oxygen and carbon dioxide between the embryo and the egg’s external environment.

Albumin

Amniotic eggs contain albumin, which provides the embryo with water and protein.

Embryo

The early developmental stage of an animal while it is in the egg.