The "B Allele" refers to one of the variations of a gene that can exist at a specific location on a chromosome. In genetics, alleles are different forms of a gene that can influence traits. The B Allele is often associated with blood type, specifically the ABO blood group system, where it contributes to the presence of the B antigen on red blood cells. In the context of the ABO blood group system, individuals can have different combinations of alleles, including A, B, AB, or O blood types. The presence of the B Allele means that a person may have type B or AB blood, which can affect blood transfusions and compatibility in medical situations.