Question

Place the steps of a polymerase chain reaction (PCR) in the correct order:

I. Annealing
II. Extension
III. Denaturation

(A) III > II > I
(B) II > III > I
(C) III > I > II
(D) I > II > III

Answer 1

The correct order of PCR steps is Denaturation, Annealing, and Extension, which is represented as denaturation (III), annealing (I), and extension (II), making option (C) III > I > II the correct answer.

Step-by-step explanation:

The correct order of steps for a Polymerase Chain Reaction (PCR) is Denaturation, Annealing, and Extension. Therefore, the correct sequence is (C) III > I > II. During the PCR process, the initial step involves denaturing the double-stranded DNA at a high temperature, which separates the DNA into two single strands. The second step is annealing, where the temperature is lowered, allowing primers to attach to their complementary sequences on the single-stranded DNA. The final step is extension, where the temperature is raised again, and the Taq polymerase synthesizes new DNA strands by extending from the primers.