AP BIOLOGY

Detailed explanation-1: -IgG antibodies are involved in the secondary immune response (IgM is the main antibody involved in primary response). IgG can bind pathogens, like for example viruses, bacteria, and fungi, and thereby protects the body against infection and toxins.

Detailed explanation-2: -The selection of the type of secondary antibody is based on the class of the primary antibody – Immunoglobulins IgG or IgM, the preferred label type, and the source host.

Detailed explanation-3: -Immunoglobulin G IgG is said to be divalent, i.e., it has two identical antigen-binding sites that comprise 2 L chains and 2 H chains joined by disulfide bonds. IgG is synthesized mostly in the secondary immune response to pathogens.

Detailed explanation-4: -The primary immune response is characterized by the appearance of neutralizing antibodies of the IgM class between days 4 and 7, several days before detection of IgG antibodies.