One cycle of PCR includes which steps?

One cycle of PCR includes which steps?

• A. Denaturation
• B. Annealing
• C. Extension
• D. Denaturation, annealing, and extension

Answer: (D)

Each PCR cycle includes three sequential steps: denaturation to separate the double-stranded DNA, annealing for primers to bind to their complementary sequences, and extension where DNA polymerase extends from the primers to synthesize new DNA. All three steps occur in every cycle in that order, enabling exponential amplification of the target DNA. The temperatures and times vary with the enzyme and primers, but the sequence remains the same.

Each PCR cycle includes three sequential steps: denaturation to separate the double-stranded DNA, annealing for primers to bind to their complementary sequences, and extension where DNA polymerase extends from the primers to synthesize new DNA. All three steps occur in every cycle in that order, enabling exponential amplification of the target DNA. The temperatures and times vary with the enzyme and primers, but the sequence remains the same.