<prompt> The enzyme used in polymerase chain reaction PCR is:Taq polymeraseRNA polymeraseRibonucleaseEndonuclease  <response>: Ans. A. Taq polymerasePolymerase Chain Reaction is a technique employed for DNA amplification. It requires the following apparatus:a. A target DNA.b. Two primers synthetic oligonucleotides of 17-30 nucleotides length that are complementary to flanked regions of DNA.c. Four dNTPs.d. A DNA polymerase mainly Taq DNA polymerase Thermo stable. It has been isolated form Thermus aquaticus. It is heat resistant, so no need to add fresh enzyme in every cycle. 