IMMUNOLOGY

Detailed explanation-1: -Secretory IgA (SIgA) is the dominant antibody class in mucosal secretions. The majority of plasma cells producing IgA are located within mucosal membranes lining the intestines. SIgA protects against the adhesion of pathogens and their penetration into the intestinal barrier.

Detailed explanation-2: -Immunoglobulin A (IgA), one of the five primary immunoglobulins, plays a pivotal role in mucosal homeostasis in the gastrointestinal, respiratory, and genitourinary tracts, functioning as the dominant antibody of immunity in this role.