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The Rh factor is another well known blood group, referring to the “positive” or “negative” in blood types, such as A-positive or B-negative. Over the last hundred years, scientists have also discovered that the ABO blood group is just one of more than 20 human blood groups. People who are type A, for instance, seem more susceptible to smallpox, while people who are type B appear more affected by some E. In some infectious diseases, bacteria may closely resemble certain blood antigens, making it difficult for antibodies to detect the difference between foreign invaders and the body’s own blood. What scientists have found in the last century, however, are some interesting associations between blood types and disease. Clearly, people who are type O- the most common blood type-do just fine without them. More than a hundred years after Landsteiner’s Nobel Prize-winning work, scientists still have no idea what function these blood antigens serve. This chart lists the antigens and antibodies made by the different ABO blood types.
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(People who are type AB inherit an A gene from one parent and a B gene from the other.) Later, researchers learned ABO blood types are governed by a single gene that comes in three varieties: A, B and O. (This is hard to keep track of, so I hope the chart below helps!)Īfter Landsteiner determined the pattern of the ABO blood group, he realized blood types are inherited, and blood typing became one of the first ways to test paternity. People who are type AB have both A and B antigens on their red blood cells and therefore don’t make any A or B antibodies while people who are type O have no A or B antigens and make both A and B antibodies. So, type A people can’t donate their blood to type B people and vice versa. The human body naturally makes antibodies that will attack certain types of red-blood-cell antigens. For example, people with type A blood have A antigens on their red blood cells and make antibodies that attack B antigens people with type B blood have B antigens on their red blood cells and make antibodies that attack A antigens. Antibodies latch onto foreign substances that enter the body, such as bacteria and viruses, and clump them together for removal by other parts of the immune system. An antigen is anything that elicits a response from an immune cell called an antibody. The “type” actually refers to the presence of a particular type of antigen sticking up from the surface of a red blood cell.
B negative blood type series#
Through a series of experiments, Landsteiner classified blood into the four well-known types. The ABO blood group was discovered in the first decade of the 1900s by Austrian physician Karl Landsteiner. But why humans and apes have these blood types is still a scientific mystery. Humans and all other apes share this trait, inheriting these blood types from a common ancestor at least 20 million years ago and maybe even earlier, claims a new study published online today in Proceedings of the National Academy of Sciences. The ABO blood group, as the blood types are collectively known, are ancient. When you get a blood transfusion, doctors have to make sure a donor’s blood type is compatible with the recipient’s blood, otherwise the recipient can die. Navy photo by Mass Communication Specialist 3rd Class Jake Berenguer/WikicommonsĮveryone’s heard of the A, B, AB and O blood types. Blood banks run blood type tests before blood is sent to hospitals for transfusions.
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