Mathematics and Society - OS X Lion Server

WffAT TVPEAilE YOII ?Blood type falls into four categories AB, B, A and O. These letters refer to certainantigens that are attached to the cell walls of red blood cells. Two of these areantigen A and antigen B. A person with blood type AB has both antigen A and antigen B.Type B blood has antigen B; type A blood has antigen A; and type 0 blood has neitherantigen A nor antigen B. Antibodies are substances in blood plasma which react with theantigens to cause clotting. A method for determining blood type involves adding antibodyA and antibody B to two blood samples and then observing the clotting reactions that takeplace. The figures below illustrate the process.ANTIBODY AAlJTlBODY A A~TIBODV BAlJTIBODY A CAUSESCLOTTING SO BLOOD\5 TYPE A.At>JTIBODY B CAUSESCLOTTI1--lG 50 BLOODIS TYPE e,.80TH AtJTIBOD IE.~CLOTTING 50 BLOODTYPE IS AB.CAU5E/>JEITI-lER ANTIBODY CA\)SESCLOTTUJG SO BLooD ISTYPE O.It may be possible to get the necessary equipment for determinin~ the blood type ofthe students in your class from the school nurse, a high school biology teacher or thelocal Red Cross Bloodmobile off Lee. Parental permission should be obtained before doingthis activity. If your students find their blood types, determine the percent of theclass that is in each blood group. If possible, combine the data from several classes.The percents below show the percents for Caucasians in the United States. (Statisticsfrom Lane Memorial Blood Bank, Eugene, Oregon.) Students could research how the percentsvary in other racesAB - Lt% B-IO% A- 42%For transfusions it is important to know blood type. Type AB contains no antibodies;type B contains antibody A; type A contains antibody B; and type 0 containsboth antibody A and antibody B. If a person received a transfusion of the wrong type ofblood, the antibodies would react with the antigen to cause clotting which would clogthe capillaries and circulatory failure would occur. The following chart shows whichtypes of ~lood can be used for transfusions. Students may be dble to determine theresults from their knowledge of antigens and antibodies.TYPE CAN R.E.CE:IVE:AB8AoABB,ABA,ABA,B,AB,OTHUS TYPE AB is CALLED THEUN1VER'OAL DOl\lOR AND TYPE. 0IS CALLED THE lJN1VER'2>ALRECIPIENT.ADAPTED FROM: Children and Ancestors in Action Biologv Series by Stanley L. Weinberg andHerbert J. Stoltze. Copyright © 1974 by Allyn and Bacon, Inc.Used by permission of Allyn and Bacon, Inc.169