What is the percentage of immunoglobulins present in proteins?: (A) 5%, (B) 10%, (C) 15%, (D) 20%
Answer is D. Immunoglobulins constitute 20 to 25% of total serum proteins. Based on physiochemical and antigenic differences, five classes of immunoglobulins have been recognized: IgG, IgA, IgM, IgD, and IgE.(Ref: Ananthanarayan 9th edition, p93)