Question

which of the following is true of PCR?

a. the enzyme used denatures at 45 degrees celsius

b. it requires primers that bind to the target DNA

c. it synthesizes RNA molecules

d. all options are true.

Answer 1

The purpose of PCR is to make a huge number of copies of a gene, gene amplification of the organism. This technique uses the dNTPs, primers, Taq DNA polymerase and template DNA. The DNA is synthesised artificially and large number of copies of genome is generated. Taq DNA polymerase is the most common enzyme used in PCR . This enzyme is extremely heat resistant with a half-life of 40 minutes at 95°C. PCR consists of the following steps: Denaturation is a process in which the template dsDNA denatures into single-strand and acts as a template to facilitate amplification. Next step is Annealing in which the primer binds to the single-stranded complementary DNA. At last Extension is carried by Taq DNA polymerase and starts DNA synthesis by adding nucleotides to the growing DNA strand. These steps repeat for 25 to 40 times in which after each cycle of amplification, the DNA templated doubled. The primers are synthesised complementary to the DNA of the organism or target which is to be amplified.

So the answer is option B. PCR requires primers that bind to the target DNA.