Question: The basic structure of a B cell receptor is best described by: Group of answer choices One light chain and one heavy chain that are covalently linked and form one antigen-binding site Two identical heavy chains and two identical light chains that are covalently linked to form one antigen-binding site Two identical heavy chains and two identical light chains that are covalently linked and form two antigen-binding sites Two identical light chains that form the antigen-binding site and two identical heavy chains that mediate the effector functions of antibodies