Question

Which of the following is a correct sequence of steps in a PCR ( Polymerase Chain Reaction)?

• A. Extension, Denaturation, Annealing
• B. Denaturation, Annealing, Extension
• C. Annealing, Denaturation, Extension
• D. Denaturation, Extension, Annealing

Answer 1

The correct option is B

Denaturation, Annealing, Extension

The correct option is B.

Explanation for Correct option:

Polymerase chain reaction or PCR is related to DNA replication or protein synthesis and consists of the following three steps:

1. Denaturation- The two DNA strands of template DNA separate from each other when heated to 92℃.
2. Annealing- The primers anneal to the 3’ end of single strands of DNA.
3. Extension- The primers are extended by DNA polymerase by the addition of nucleotides to form complete strands of DNA. Hence the sequence of steps is denaturation, annealing, and extension.

Final answer: Correct sequence of steps in a PCR ( Polymerase Chain Reaction): Denaturation, Annealing, Extension