Question

Which of the following is true of PCR?

	1.	The enzyme used denatures at ~45oC
	2.	It requires primers which bind to the target DNA
	3.	All the options are true
	4.	It synthesizes RNA molecules

Answer 1

Here option 2 is correct

PCR has 3 basic steps :denaturation, primer annealing, primer extension

During the second step, primers(a short sequence of nucleotides that provides a starting point for DNA synthesis) anneal to each of the single stranded DNA at its 3' end.

In the remaining options,

1.The enzyme used for PCR is Taq polymerase which is a thermostable DNA polymerase which remains active around 700C.

4.During the third step Taq polymerase extends the primers, synthesising new strands of DNA.