Question

How can PCR amplify one segment of DNA from a complex mixture of potential template molecules?

a) By separating the DNA into individual strands
b) By using a specific polymerase enzyme
c) By targeting specific sequences with primers
d) By using gel electrophoresis

Answer 1

PCR amplifies a specific DNA segment by using specific primers that bind to targeted sequences, coupled with DNA polymerase that extends these primers in a repeated cycle, creating millions of copies. Therefore, the correct option is C.

Step-by-step explanation:

PCR, or Polymerase Chain Reaction, can amplify one segment of DNA from a complex mixture of template molecules by using specific primers that target the sequences of interest. During the procedure, the targeted DNA is denatured by heating, which separates the DNA into single strands. Next, the annealing phase allows the primers to hydrogen-bond to their complementary sequences on the DNA strand. Finally, DNA polymerase extends these primers, creating a new complementary strand in the extension phase. This cycle is repeated to exponentially amplify the targeted DNA segment, allowing scientists to produce millions of copies in a short amount of time. This selective and efficient method is due to the specificity of the primers used in the PCR process.