Question

Which of the follwoing is true regarding the DNA polymerase used in PCR?

• A. It is used to ligate introduced DNA in recipient cells.
• B. It serves as a selectable marker
• C. It is isolated from a virus
• D. It remains active at high temperature

Answer 1

The correct option is D It remains active at high temperature

In PCR, Taq polymerase is used which is obtained from the bacterium Thermus aquaticus that is found in thermal vents. Since this bacteria survives in high temperatures, its polymerase enzyme is heat resistant. Since it is a relatively thermostable enzyme, it is used in PCR during the step involving denaturation of DNA strands that requires a high temperature.