Lesson eLearning

Which DNA polymerase is most commonly used in PCR because it remains active after repeated cycles of high temperature denaturation?

easy MCQ 1 mark Class 12 · Biology · Biotechnology and Its Applications
  1. Taq DNA polymerase
  2. DNA polymerase I
  3. Pfu DNA polymerase
  4. Reverse transcriptase
Answer
Taq DNA polymerase

The correct answer is Taq DNA polymerase — Thus the most commonly employed enzyme is Taq.

Step-by-step solution

  1. Taq DNA polymerase is derived from the thermophilic bacterium *Thermus aquaticus*.
  2. It has intrinsic heat‑stability, allowing it to survive the high temperatures used for DNA denaturation.
  3. Hence, it can be reused in successive PCR cycles without losing activity.
  4. This property makes it the polymerase of choice for standard PCR protocols.
  5. Other polymerases such as Pfu are more accurate but are inactivated during the cycles.
  6. Thus the most commonly employed enzyme is Taq.
Common mistake: Confusing the use of Pfu DNA polymerase with Taq as the standard PCR enzyme

Concept tested: PCR enzyme selection

Published · How this solution was prepared and checked

← All Biotechnology and Its Applications questions