Wiki User
∙ 14y agoIt's a sack and not an egg but the primary food source, the only one, is the placenta and the nutrients go via the umbilical cord.
Emiliano Torp
Wiki User
∙ 14y agoThe yolk is the complete source of nutrition for the growing embryo of a fertilized and incubated egg.
The white part or albumen is only 15% proteins and it's main function is to protect the yolk.
Wiki User
∙ 9y agoThe down part
In birds and reptiles only .
An egg.
Initial development of the egg, including the embryo, begins inside the mother bird after she mates with a male. The embryo, yolk, and shell initially form together. After the egg is laid the bird embryo continues to grow, drawing the nutrients it needs from the yolk.
The same way as a birds egg - with a yolk sac. The embryo feeds off the yolk-sac while it's developing inside the egg.
No, That means it is infected with bacteria and is about to explode. If you had candled them earlier you would have noticed there wasn't an embryo growing inside and could have discarded it then. The best thing to do is to carefully cover it with a damp washcloth and remove if from the incubatorbecause if it explodes most of the birds that hatch will die.
The embryo gets nutrients from the mother during pregnancy through the placenta. The placenta is a temporary organ that develops in the uterus and allows for the exchange of nutrients, oxygen, and waste products between the mother and the fetus.
Marsupial embryos do not have an amnion. Instead, they develop within a pouch called a marsupium on the mother's abdomen.
They create it as part of their metabolism, the activities of living, growing, and moving.
AlexisLawrence Romanoff has written: 'Pathogenesis of the avian embryo' -- subject(s): Abnormalities (Animals), Abnormities and deformities, Birds, Chick Embryo, Embryobiology, Fetus
So the embryo can breathe!!
Mammals, birds, and reptiles all derive from a single common ancestor.
No, they do not.