Where do you think a chick growing inside an egg gets food from?

Inside an eggshell, a developing chick relies on the yolk sac for nourishment. The yolk sac is a membrane-lined sac attached to the embryo and filled with a nutrient-rich substance containing proteins, fats, vitamins, minerals, and water. As the chick grows and develops inside the egg, it progressively absorbs the nutrients from the yolk sac through the yolk stalk. The yolk sac is gradually reduced in size and eventually gets pulled into the chick's body just before hatching.