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: Pediatrics
[{'content': '10 years old Ramu has increasing muscle weakness and raised CPK levels. The most likely defect is in plasma membrane of – \nSelect and explain. \nA. Nerves, B. Muscle fibres, C. Basement membrane, D. All body cells', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Increase in CPK level with muscle weakness suggests muscle cell damage.\nCreatine kinase is an enzyme found mainly in → Skeletal muscle, Heart, Brain\nIts levels will be raised in the serum when any of the above mentioned cell is damaged.\nThere are various isotypes of the enzyme which are specific for difference cells.\n\n\xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 Enzyme \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 Tissue\n\nCreatine kinase (MB\xa0isoenzyme)\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0 Heart\nCreatine kinase (BB isoenzyme)\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0 Brain\nCreatine kinase (MM isoenzyme)\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0 Skeletal muscle\nOther enzymes elevated in muscle diseases \xa0\xa0→ Aldolase, Aminotransferases specially (ACT), Lactate dehydrogenase', 'role': 'assistant'}]