AP BIOLOGY

Detailed explanation-1: -If you have an AA or AO genotype, you will have the phenotype of type A blood; if you have a BB or BO genotype, you will have a type B blood phenotype; if you have an AB genotype, you will have a type AB blood phenotype; and if you have an OO genotype, you will have a type O blood phenotype.

Detailed explanation-2: -Genotype AA is the universally compatible genotype that is, regardless of who they partner up with, there is no possibility of them birthing a child with sickle cell disease. Here are the compatible and incompatible genotypes: AA + AA = compatible. AA + AS = compatible.

Detailed explanation-3: -Under this system phenotypes designated by a capital letter such as A would correspond to either a homozygous dominant (AA) or heterozygous (Aa) genotype while phenotypes designated by a lower case letter such as a would correspond to homozygous recessive genotype (aa).