This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Metabolism of protein and amino acid, Subject name: Biochemistry
[{'content': 'Transversion seen in \nSelect and explain. \nA. Guanine - cytosine, B. Guanine - adenine, C. Guanine - thymine, D. Adenine - thymine', 'role': 'user'}, {'content': 'Answer: A \nExplanation: SubstitutionReplacement of a purine by another purine (A to G or G to A) or pyrimidine by pyrimidine(T to C or C to T) is called transition mutation. If purine is changed to a pyrimidine (A to C) or a pyrimidine to a purine(T to G), it is called a transversion mutation.Ref: Textbook of biochemistry ( DM Vasudevan), 6th edition, page no. 612', 'role': 'assistant'}]