This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Metabolism of nucleic acids, Subject name: Biochemistry
[{'content': 'Which of the following would form the basis for karyotyping studies in female? \nSelect and explain. \nA. Phenotype abnormality, B. Testoterone quantity, C. Barr body, D. Not recalled', 'role': 'user'}, {'content': "Answer: C \nExplanation: Females contains two 'X'chromosomes. An extra 'X' chromosome contains Barrbody.Therefore , normal female contains one Barrbody. Males only single 'X' chromosome is present which results in absence of Barr body. so this helps in karyotyping studies", 'role': 'assistant'}]