If you only have hens then no it is not possible. You need a rooster with the hens to get an embryo.
The beginning of a chick.
Yes that is possible, it has happened twice to me!
the developing embryo is nourished by yolk
A hen will start laying eggs at about 21 weeks old and should continue for a few years
The yolk is the highly nutritional food for the developing embryo of a fertilized egg.
It is to protect the embryo inside the egg.
It gives the embryo oxygen it needs to survive in the egg.
An egg yolk is the part of an egg which serves as the food source for the developing embryo inside.
When a hen lays a fertilized egg, there is no embryo inside. Embryo's only start to form once they are incubated.
The yolk inside the egg.
The developing embryo takes its nourishment from the yolk inside the egg. The embryo doesn't need air until it is ready to break out of its shell.
The little black dot in the egg is the part that grows into an embryo.