This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Genetics, Subject name: Pathology
[{'content': 'F body is \nSelect and explain. \nA. Y chromatin, B. X chromatin, C. Chromosome 1, D. Chromosome 21', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. (a) Y chromatin(Ref: Emery Genetics)Quinacrine, a fluorescence dye, binds strongly to the Y chromosome forming a bright fluorescent spot (F body). This is clearly visible in stained interphase cells from various tissues from the human male and in mature spermatozoa', 'role': 'assistant'}]