This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Specific Cytogenetic Disorders, Subject name: Pathology
[{'content': 'Chromosome 21 belongs to which of the following subtype? \nSelect and explain. \nA. Acrocentric chromosome, B. Metacentric chromosome, C. Submetacentric chromosome, D. Telocentric chromosome', 'role': 'user'}, {'content': "Answer: A \nExplanation: Two different arms of the chromosome are separated by a structure known as Centromere. Location of centromere Type of chromosome Example Exactly in the middle Metacentric Towards one side Sub-metacentric 'X' chromosome On the one end Acrocentric 'Y' chromosome, 13,14,15,21,22 chromosome. Right at the tip Telocentric Not seen in humans", 'role': 'assistant'}]