How can non-mammals that hatch from shells survive while they don’t have an umbilical cord connected them to the mother and sustaining them?
In: Biology
The yolk provides the nutrients the umbilical would.
The oxygen from the air passes through the shell (if it’s there) and into the “egg whites” and into the growing animal.
Short answer. They do have an umbilical cord of sorts.
If you ever broke open an egg with a developing chicken inside you’d note that it’s digestive system is directly connected to the yolk sack.
That’s what eggs basically are, a ball of all the nutrients a developing embryo needs to grow until it hatches.
Because all of the nutrients and things needed for the embryo to grow are already in the egg. That’s what the yolk and white of an egg are. As the embryo grows, it basically has an umbilical cord attached to the yolk and the embryo consumes the yolk that way.
The yolks of the egg nourishes the baby inside the egg. So, instead of the mother supplying nutrients through a long pregnancy, they front load the nutrients when they lay the egg.
That’s what the egg white and yolk (primarily the yolk) is for. They supply nutrients to the developing embryo.
So… Eggs to chickens?
Latest Answers