Reptiles, mammals, and birds lay amniotic eggs, which contain a yolk to nourish the developing organism. Eggs are used to protect the organism as it develops, and the egg also aids in gas and energy exchange. Hope this helped :)
Inside the egg are a series of fluid-filled membranes which permit the embryo to survive,the amnion allantois yolk sac, and chorion. Surrounding and protecting the embryo is the amnion, filled with amniotic fluid and providing the embryo with a stable fluid environment.
