<prompt> Which immunoglobulin crosses placenta?IgGIgMIgAIgD  <response>: Ans. a IgG. Ref. Textbook of Microbiology by Anantanarayan, 6th82FeaturesIgGIgAIgMIgDIgE1Sr. Cone, mgml1221.20.030.000042Half Life Days23652-81-53Daily Production Meg Kg34243.30.40.000234Carbohydrate 381213125Complement fixation - Classical---6Complement fixation - Alternative----7Placental Transfer---8Heat Stability 56deg c-9Synthesized earliest phylogenetically oldest----10J-chain-- 11Secreted by seromucinous glands---- 