Question

The denaturation process in Polymerase Chain Reaction (PCR) does not involve

• A. breaking of hydrogen bonds of the original DNA double helix
• B. heating of starting solution to $94^{o}C$
• C. addition of nucleotides to the primer by DNA polymerase
• D. creation of single-stranded DNA templates

Answer 1

Answer: (C)

PCR stands for Polymerase Chain Reaction. In this reaction, gene (segment of DNA) of interest is synthesised in vitro and multiple copies are generated. The main steps of PCR-
Denaturation - where the double-stranded template DNA is heated to separate it into two single strands.
Annealing - where the temperature is lowered to enable the DNA primers to attach to the template DNA.
Extension - where the temperature is raised and the new strand of DNA is made by the Taq polymerase
enzyme. Thus, option C is correct as it is part of extension step and not denaturation.