KCET 2020 Biology Solved Paper

Polymerase chain reaction includes three steps - denaturation, annealing and elongation or extension.
Denaturation - the process by which the DNA strands unwind and denature to form two separate strands. This step occurs at a very high temperature.
Annealing - the process by which the DNA primer attaches to the DNA template strand by complementary base pairing.
Elongation - it is the process of addition of nucleotides. A thermostable enzyme called Taq polymerase. This enzyme is extracted from the bacteria called Thermus aquaticus.