This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Transcription, Subject name: Biochemistry
[{'content': 'Initiation and Termination of a sequence of intron : \nSelect and explain. \nA. GU,AG, B. AG,GU, C. GA,GU, D. UG,AG', 'role': 'user'}, {'content': 'Answer: A \nExplanation: The sequence of the intron is unique. It always stas with GU and ends with AG Any mutation in these sequences will lead to defective splicing. e.g. b thalassemia.', 'role': 'assistant'}]