This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
[{'content': 'True about polymerase chain reaction (PCR) - \nSelect and explain. \nA. Carried out by thermostable DNA polymerase, B. Exponential, C. Specific, D. All of these', 'role': 'user'}, {'content': 'Answer: D \nExplanation: In PCR, thermostable DNA polymerase (Taq polymerase) is used because, in PCR, DNA is to be heated upto 94-95°C for separation of two strands of DNA.\nEach cycle doubles the amount of DNA in the sample, leading to exponential increase (not additive) with the repeated cycle of amplification.\nSpecific primers are required, that have a nucleotide sequence complementary to flanking region of target DNA.\n\nDouble-stranded DNA sequence is amplified in PCR.', 'role': 'assistant'}]