Question

Which of the following is in the correct order for one cycle of polymerase chain reaction (PCR)? Which of the following is in the correct order for one cycle of polymerase chain reaction (PCR)? Extend primers; anneal primers; denature DNA. Denature DNA; add fresh enzyme; anneal primers; add dNTPs; extend primers. Denature DNA; anneal primers; extend primers. Add fresh enzyme; denature DNA; anneal primers; add dNTPs; extend primers. Anneal primers; denature DNA; extend primers.

Answer 1

Answer:

Denature DNA; anneal primers; extend primers.

Explanation:

PCR (polymerase chain reaction) amplifies a small amount of sample DNA into multiple copies. The reaction mixture mainly consists of Taq polymerase enzyme, primers, sample DNA to be amplified, and deoxyribonucleotides (dNTPs). The first step is the denaturation of the DNA molecule into single strands and is facilitated by heat. This is followed by primer annealing to the single-stranded DNA molecules. Primers attach to the primer-binding site on each DNA strand which in turn now serves as a template for DNA synthesis catalyzed by Taq DNA polymerase. Extension of primers by the addition of dNTPs produces new DNA molecules.