Chicken eggs aren’t just breakfast—they’re tiny biological marvels. Whether you keep hens for eating eggs or hatching chicks, understanding egg anatomy helps you spot what’s normal, protect food safety, and improve hatch results.

1) Shell & Bloom

The shell is primarily calcium carbonate, with a protective cuticle (bloom) that seals pores and keeps bacteria out.

2) Shell Membranes & Air Cell

Two membranes act as barriers; the air cell forms as the egg cools and is vital for chick hatching.

3) Albumen & Chalazae

The egg white cushions the yolk and contains proteins; chalazae keep the yolk centered.

4) Yolk & Germinal Disc

The yolk provides nutrition, and the germinal disc is the starting point of a chick if fertilized.

5) Fertility Basics

Unfertilized eggs are for eating; fertilized eggs require a rooster and can develop into chicks under incubation.