AAB Medical Technologist (MT) 2026 – 400 Free Practice Questions to Pass the Generalist Exam

The term "phenotype" specifically refers to the observable characteristics or traits of an individual, which can be the expression of various genes in the context of blood typing. In blood typing, the phenotype would describe the blood group that is visible and can be tested, such as A, B, AB, or O, based on the presence or absence of specific antigens on the surface of red blood cells.

This definition highlights the physical expression of genetic information, distinguishing it from the underlying genetic makeup or genotype, which encompasses the alleles an individual carries. In blood typing, while the genotype may determine the phenotype, it is the observable blood group that is relevant for transfusion compatibility and other clinical considerations, reinforcing why the observable characteristics are central in this context.