Question

What are the three steps of PCR?

1) Denaturation, Annealing, Extension
2) Extension, Denaturation, Annealing
3) Annealing, Extension, Denaturation
4) Denaturation, Extension, Annealing

Answer 1

The three steps of PCR are 1) Denaturation, 2) Annealing, and 3) Extension, which allow the amplification of DNA segments by heating and cooling at specific temperatures to enable the binding of primers and synthesis of a new DNA strand.

Step-by-step explanation:

The three steps of Polymerase Chain Reaction (PCR) are 1) Denaturation, 2) Annealing, and 3) Extension. This sequence of steps is critical for the amplification of DNA.

Denaturation involves heating the DNA to a high temperature to separate the two strands of the DNA helix. During annealing, the temperature is lowered to enable DNA primers to attach to their complementary base pairs on the single-stranded DNA templates. Lastly, extension takes place at an intermediate temperature where the DNA polymerase synthesizes a new strand of DNA by adding nucleotides to the primers.

By repeating these steps typically 25-40 times, PCR can amplify a targeted DNA sequence by millions to over a trillion copies, which can then be used for various genetic analyses.