Type of immunoglobulin Characteristic A. IgG 1. First antibody produced during primary immune response B. IgA 2. Found in mucosal areas like the gut, respiratory tract, and urogenital tract C. IgM 3. Provides long-term immunity; crosses the placenta D. IgE 4. Involved in allergic reactions; binds to mast cells and basophils

Step-by-step solution

IgG is the most abundant immunoglobulin in the blood and is critical for long-term immunity. It is the only immunoglobulin that can cross the placenta, providing passive immunity to the fetus. IgA is primarily found in mucosal areas, such as the gut, respiratory tract, and urogenital tract, and in secretions like saliva, tears, and breast milk. It plays a crucial role in mucosal immunity. IgM is the first antibody produced in response to an infection during the primary immune response. It is also the largest antibo