Which of the following is true about IgG antibody?: (A) Produced in primary immune response, (B) Cannot cross placenta, (C) Provides local protection, (D) Produced in secondary immune response
Answer is D. IgG contains 2 heavy chains and 2 light chains;heavy chains being of gamma type. It is the major antibody;it constitutes of 75 -80% of total immunglobulins in circulation. It is the antibody seen in secondary immune response. It can pass from vascular compament to interstiitial space. REFERENCE: DM VASUDEVAN TEXTBOOK SEVENTH EDITION ; PAGE NO : 688