OSMT (Ontario Society of Medical Technologists) Practice Exam

Antibodies classified as monomers include:

1. a. IgA, IgD, IgG

2. b. IgE, IgA, IgD

3. c. IgE, IgD, IgG

4. d. IgM, IgG, IgE

The correct answer is: c. IgE, IgD, IgG

Monomeric antibodies are characterized by their structure, consisting of a single unit. Among the antibody classes, IgD, IgG, and IgE are indeed classified as monomers. IgD is primarily found on the surface of immature B lymphocytes and plays a role in the immune response as a receptor for antigens. IgG is the most abundant antibody in serum and is crucial for the body's defense against pathogens. IgE, while less abundant, is responsible for allergic reactions and protection against parasitic infections. In contrast, IgA typically exists as a dimer in its secretory form, while IgM is a pentamer, meaning it consists of five antibody units linked together. Thus, the inclusion of IgA or IgM in any choice indicating only monomeric antibodies would be incorrect. This clarification of the structure and function of these antibodies helps to reinforce the understanding of their classifications and roles in the immune response.