Why Must DNA Fragments Be Denatured During the Polymerase Chain

Question

Why must DNA fragments be denatured during the polymerase chain reaction?
A) Taq polymerase breaks down when heated.
B) The repeated gene sequences are not present in double-stranded DNA.
C) The primer must bind to a single-stranded template to synthesize double-stranded DNA.
D) VNTRs have DNA sequences that vary in number.

Accepted Answer

During the polymerase chain reaction, the DNA fragments must be denatured or separated into single strands so that the primer can bind to a single-stranded template and synthesize double-stranded DNA. Taq polymerase is heat-stable, so option A is not correct. Option B is incorrect because repeated gene sequences are commonly found in double-stranded DNA. Option D is also incorrect because VNTRs (variable number tandem repeats) are regions of DNA where the number of repeats varies, but this does not relate to the denaturation of the DNA fragments during PCR.