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': 'Barr body is absent is females having - \nSelect and explain. \nA. 46 XX genome, B. 45 XO genome, C. 47 XXX, D. All of the above', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Barr body \n\nDiscovered by Murray Ban\nInactive X-chromosome\nUsually in female, One X-chromosomes is always inactive and detected as Barr body.\nNormal 46 XX → One barr body seen\nSuper female 47 XXX → Two barr body seen\nKlinefelter 47 XXY(males) → Single barr body\nTurner 45 XD → Barr body absent\nBarr body is seen in nucleus of neutrophils.\n\nBarr body: \n\nSex chromative mass seen within nuclei of normal female somatic cell.\nAcc. to Lyon hypothesis, one of two x-chromosome in each somatic cell is genetically inactive and repersent barr-body.\nKlinefilter syndrome (XXY) → One inactive X-chromosome ban body.\nIf XXXY = 2 Ban body\n\nXO = 0 Ban body\nXY = 0 Ban body\nXX = 1 Ban body', 'role': 'assistant'}]