Blood Types, American Red Cross, "Although all blood is made of the same basic elements, not all blood is alike. In fact, there are eight different common blood types, which are determined by the

Blood Types, By Paul Andersen, BozemanScience.com, Video length: 10:45, Paul Andersen explains the importance of blood types in blood transfusions. He starts with a brief discussion of blood

Blood Types, Khan Academy, YouTube.com, Video length: 08:52.

Blood Types: What's the difference, The Human Heart, The Franklin Institute, Excellent description of A, B, AB, and O blood types.

Genes and Blood Types, The Genetic Science Learning Center, University of Utah, Blood types are determined by genetics. Here you can find information on A, B, AB, and O blood types. Includes illu

The Blood Typing Game, NobelPrize.org, What happens if you get a blood transfusion with the wrong blood type? Even though a patient's own blood type is the first choice for blood transfusions, i

What is a blood type?, NobelPrize.org, There are eight blood types. Learn all about them here with a combination of text and illustrations.

Why Monkeys Matter, The Human Heart, The Franklin Institute, Explains how a scientist came up with the Rh factor and what it means.