Why eggs have yolk and white ?

We usually use chicken's eggs for cooking.

Eggs have various structure to make chick's body and protect chick's life until hatching.

If you look closely at the yolk, you will see a white spot called an embryo.

embryo is the important part that will be chick.

yolk is wrapped in the yolk membrane and gives nutrients to embryo.

Egg white wraps yolk like a cushion to protect it.

Egg white keeps moisture and gives nutrients to embryo too.

Egg white is wrapped in the eggshell membrane, the outermost part is covered with eggshell.

Chalaza connects eggshell membrane and yolk, has elasticity like rubber.

Chalaza fixes yolk in the center to soften the impact from the outside.

Let's check the process to make chick's body.

Female chicken has ovary, ovaries have many small grains that is resource to be yolk.

the grain grows, and become yolk in ovary, then the yolk advances to the fallopian tubes one by one every day.

In the fallopian tubes, in order, egg white, chalaza, eggshell membrane, and finally the eggshell are made, and it will be born about 25 hours later.

Next, let's take a look at the process of chicks being born.

When the hen begins to warm the egg, the embryo changes into various organs such as nerves, brain, and internal organs.

Embryos take in nutrients from yolks and grow steadily, and when they are warmed for about 16 days, their feathers begin to align.
A chick is born about 21 days after the hen begins to warm the egg.