Components of Blood

Identify the four components of blood.

The student will identify the four components of blood and theirrelative amounts. The student will understand the function of eachblood component.


  • Candy red hots
  • Corn syrup
  • White jellybeans or marshmallows
  • Candy sprinkles


  1. Explain the four components of blood:
    • Red blood cells (candy red hots): 44% of blood volume, carry oxygen and carbon dioxide around body. RBC’s only live for about 3 months, but are continuously produced in the bone marrow.
    • Plasma (corn syrup): 55%, syrups, thick, clear, yellowish liquid that carries dissolved food and wastes.
    • White blood cells (white jelly beans or marshmallows): 0.5%, bigger than red blood cells, oddly shaped cells that “eat” bits of old blood cells and attack germs.
    • Platelets: 0.5% -bits of cells and cytoplasm that help clot your blood.
  2. Emphasize the relative amounts of the blood components. Mix the candy “blood” in a large, clear container. Dispense into small cups, and pass out one cup to each student. Supply spoons so that the students can eat the candy if they desire.

Interesting Fact: There are 5 million red blood cells, 10 thousand white blood cells, and 250 thousand platelets in a pinhead-size drop of blood.

Additional Info

Lesson adapted from and submitted by Kathy Searle.