This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
[{'content': 'Defect leading to thalassemia lies in - \nSelect and explain. \nA. Haemoglobin, B. Osmotic fragility, C. RBC membrane, D. Platelets', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Disorders of haemoglobin\nDisorders of haemoglobin may be of two types : -\n1. The qualitative defect of haemoglobin (hemoglobinopathy)\n\nHemoglobinopathies are disorders of haemoglobin, characterized by a defect that results in the abnormal structure of one of the globin chain of haemoglobin.\nExamples are - Sickle cell anemia, HbC, HbE, HbD-Punjab, HbO-Arab, Hb Lepore.\n\n2. The quantitative defect of haemoglobin\n\nThese disorders are characterized by a defect that results in a decreased rate of synthesis of one of the globin chain of haemoglobin.\n\nExample - Thalassemia', 'role': 'assistant'}]