1. Human Blood Groups- Multiple Alleles AND CoDominance OK… Humans and many other primates

2. Recall: There are three different alleles for human blood type (multiple alleles): AllelesBlood Type IAIA A IBIB B i O “A” indicates the presence of 1 type of antigen (protein that can “activate” your immune system) and “B” represents a different antigen on the surface of a red blood cell “O” has no antigen on the surface of the RBC

3. Allele from Parent 1 Allele from Parent 2 Genotype of offspring Blood types of offspring (Phenotype) AAAAA AOAOA BBBBB BOBOB ABAB OOOOO

4. Antibodies A “foreign” antigen will trigger your immune system to create antibodies. Since antibodies are proteins, they have a specific shape & will attach onto the antigen for which they were made. There are bacteria in the atmosphere that have a very similar shape to our “A” and “B” antigens & we are exposed to them as soon as we are born.

5. Therefore, each person can have antibodies against an antigen they didn’t inherit. These antibodies are floating around in our blood with our RBC’s.

6. Type A blood (has A antigens on cell surface) has Anti-B antibodies –Antibodies are named for what they attack –Anti-B antibodies attack and will clump up (agglutinate) in the presence of B-antigen Type B blood (has B antigens on cell surface) has A-antibodies

7. Type AB blood doesn’t have any antibodies Type O blood has Anti-A and Anti-B antibodies

9. Rh Factor The Rh factor genetic information is also inherited from our parents, but it is inherited independently of the ABO blood type alleles (a separate gene).

10. MotherFatherChild Rh-Rh+ Rh- There are 2 different alleles for the Rh factor known as Rh+ and Rh-. Normal dominant/recessive inheritance Positive (+) allele is dominant to negative (-) allele Rh +: you have the proteinRh-: you don’t

13. The “Rh Issue”… Mom = Rh- Baby #1 = Rh+