This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General Microbiology Pa 1 (History, Microscopy, Stains and Structure and Physiology of Bacteria), Subject name: Microbiology
[{'content': 'PCR is used to : \nSelect and explain. \nA. Detect target plasmids, B. Amplify small amount of DNA, C. Seal the cut ends of DNA, D. Cleave the bacterial plasmid', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Polymerase chain reaction (PCR) - used to amplify small amount of DNA In 1983, Kary Mullis developed a new technique that made it possible to synthesize large quantities of a DNA fragment without cloning it. Basic Steps involved in PCR are: a) DNA extraction from microorganism b) Amplification of extracted DNA- 3 steps -Denaturation (95degC), Primer annealing (55degC), Extension (72degC) c) Post amplification analysis by different methods like Gel electrophoresis.', 'role': 'assistant'}]