ABO blood group system gives type O. As both "I" and "I" are dominant over "i", only "ii" people have type O blood. Individuals with "II" or "Ii" have type A blood, and individuals with "II" or "Ii" have type B. "II" people have both phenotypes, because A and B express a special dominance relationship: codominance, which means that type A and B parents can have an AB child. A couple with type A and type B can also have a type O child if they are both heterozygous ("Ii","Ii"). The "cis-AB" phenotype has a single enzyme that creates both A and B antigens.
Blood donation blood to prepare for a disaster. The subject was discussed at length after the September 11 attacks in the United States, and the consensus was that collecting during a disaster was impractical and that efforts should be focused on maintaining an adequate supply at all times. Blood centers in the U.S. often have difficulty maintaining even a three-day supply for routine transfusion demands. The World Health Organization (WHO) recognizes World Blood Donor Day on 14 June each year to promote blood donation. This is the birthday of Karl Landsteiner, the scientist who discovered the ABO blood group system. The theme