Incubation and Embryology - University of Illinois

What Is an Egg?


Science, Art, Language Arts, Mathematics


Students will learn to identify the parts of the egg.
Students will observe the composition of the egg parts.


  • fresh eggs
  • hard boiled eggs
  • saucers or petri dishes
  • colored pencils or markers
  • magnifying glasses (optional)


  1. The structure of an egg An egg is a reproductive cell from which a new organism develops. This will occur only if the egg has been united with a male sperm cell (fertilized). A chick will hatch from a fertile egg if the egg is incubated at 100.5 degrees F for 21 days. You can tell if an egg is fertile by candling and identifying a mass or small spot in the egg. The egg will appear incandescent, and the mass will be dark.
  2. Identify the parts of the egg
    1. Blastoderm
    2. Yolk
    3. Albumen
    4. Inner shell membrane
    5. Outer shell membrane
    6. Air cell
    7. Shell
  3. Look at an egg
    Crack fresh egg into saucer and locate all the parts listed on the diagram.
  4. Draw and label the egg as it is in the dish
    Crack and peel a hard cooked egg. Try to locate the parts found on the egg diagram. Can you find them? Why or why not?

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