PCR and DNA Amplification — NEET Biology

PCR (Polymerase Chain Reaction) is an in vitro technique that creates millions of copies of a specific DNA segment rapidly using DNA polymerase enzyme. Students often confuse PCR with actual DNA replication in cells—remember, PCR is artificial and happens in a test tube, not inside cells. The key trap is misunderstanding that PCR requires repeated cycles of heating and cooling (denaturation, annealing, extension) to amplify DNA exponentially. To score correctly: PCR uses temperature cycling, requires primers and dNTPs, doubles DNA in each cycle, and produces 2^n copies after n cycles. This concept tests your understanding of modern biotechnology tools essential for genetic engineering and forensics.