This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Structure and function of protein, Subject name: Biochemistry
[{'content': 'Which of the following is true about IgG antibody? \nSelect and explain. \nA. Produced in primary immune response, B. Cannot cross placenta, C. Provides local protection, D. Produced in secondary immune response', 'role': 'user'}, {'content': 'Answer: D \nExplanation: 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', 'role': 'assistant'}]