Question

Which of the following represents the correct order of steps in a PCR reaction beginning with double-stranded DNA?

a) Annealing, Denaturation, Extension
b) Denaturation, Annealing, Extension
c) Extension, Denaturation, Annealing
d) Extension, Annealing, Denaturation

Answer 1

The correct order of steps in a Polymerase Chain Reaction (PCR) is Denaturation, Annealing, Extension. Denaturation separates the DNA strands, Annealing allows primers to bind, and Extension enables DNA synthesis. These steps are repeated in cycles to amplify DNA.

Step-by-step explanation:

The correct order of steps in a Polymerase Chain Reaction (PCR) beginning with double-stranded DNA is: Denaturation, Annealing, Extension. These steps are described as follows:

1. Denaturation: This step involves heating the double-stranded DNA to separate it into two single strands.
2. Annealing: During annealing, the temperature is lowered to allow primers to bind to their complementary sequences on the single-stranded DNA.
3. Extension: Finally, the temperature is raised for the Taq polymerase to synthesize new strands of DNA by adding nucleotides to the primers.

Each cycle of PCR is designed to double the amount of the specific DNA segment being amplified, and this process is repeated for multiple cycles to exponentially increase the number of copies.