PCR proceeds in three distinct steps governed by temperature, they are in order of
denaturation, annealing, extension.
extension, annealing, denaturation
annealing, extension, denaturation
denaturation, extension, annealing
In polymerase chain reaction (PCR) each cycle has three steps: (i) Denaturation; (ii) Primer annealing; and (iii) Extension of primers