IMMUNOLOGY

Detailed explanation-1: -During the first encounter with a virus, a primary antibody response occurs. IgM antibody appears first, followed by IgA on mucosal surfaces or IgG in the serum. The IgG antibody is the major antibody of the response and is very stable, with a half-life of 7 to 21 days.

Detailed explanation-2: -IgM is the primary antibody produced during an initial antigen challenge.

Detailed explanation-3: -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.

Detailed explanation-4: -IgM is the first class of immunoglobulin made by B cells as they mature, and it is the form most commonly present as the antigen receptor on the B-cell surface. When IgM is secreted from the cells, five of the basic Y-shaped units become joined together to make a large pentamer molecule with 10 antigen-binding sites.

Detailed explanation-5: -Primary Immune Response: A large amount of IgM and a small amount of IgG are produced during the primary immune response. Secondary Immune Response: A large amount of IgG, a small amount of IgM, IgA, and IgE are produced during the secondary immune response.