Final answer:
Yes, both MHC I and MHC II have multiple alleles. MHC I molecules present normal self-antigens and abnormal/nonself pathogens, while MHC II molecules present abnormal/nonself pathogen antigens. Both MHC I and MHC II genes have highly polymorphic alleles.
Step-by-step explanation:
Yes, both MHC I and MHC II have multiple alleles. MHC (Major Histocompatibility Complex) is a group of genes responsible for encoding cell surface proteins that play a crucial role in the immune system. MHC I molecules are found on all nucleated cells and present normal self-antigens as well as abnormal or nonself pathogens to effector T cells. MHC II molecules are found on macrophages, dendritic cells, and B cells, and they present abnormal or nonself pathogen antigens for the initial activation of T cells. Both MHC I and MHC II genes have highly polymorphic alleles, contributing to the diversity of immune responses in individuals. For example, in humans, there are six MHC molecules that show the most polymorphisms - three class I molecules (A, B, and C) and three class II molecules (DP, DQ, and DR).