Indicate whether each of the following descriptions better applies to class I (1) or class II (2) MHC proteins of vertebrates. Your answer would be a four-digit number composed of digits 1 and 2 only, e.g. 2221.
( ) They mainly present intracellular peptide fragments.
( ) They are found on most nucleated cells.
( ) They present antigens mainly to helper or regulatory T cells.
( ) They are recognized by CD4 co-receptors on helper and regulatory T cells.

Question

Indicate whether each of the following descriptions better applies to class I (1) or class II (2) MHC proteins of vertebrates. Your answer would be a four-digit number composed of digits 1 and 2 only, e.g. 2221.
( )	They mainly present intracellular peptide fragments.
( )	They are found on most nucleated cells.
( )	They present antigens mainly to helper or regulatory T cells.
( )	They are recognized by CD4 co-receptors on helper and regulatory T cells.

Quizplus · Accepted Answer

Class I MHC proteins are found on the surface of most nucleated cells and mainly present intracellular antigens. Class II MHC molecules are present on special immune cells such as dendritic cells and present mainly extracellular antigens to helper or regulatory T cells with the help of CD4 co-receptors.

Indicate Whether Each of the Following Descriptions Better Applies to Class