polymerase chain reaction

Question 1

what does the method do

Answer 1

a method by which a small, specific section of DNA can be copied repeatedly to get a large quantity of that particular bit of DNA

= amplification of DNA

Question 2

primers used

Answer 2

2 primers

one primer to bind on each DNA strand

OR

1 primer each to indicate the start and end of the DNA sequence to be copied/amplified

Question 3

first step of PCR

Answer 3

denaturation step - H-bond and make the DNA template single-stranded

Question 4

second step

Answer 4

annealing step - allow primers to bind to complementary DNA sequence by H-bonds

Question 5

step 3

Answer 5

extension / polymerisation step - allow DNA nucleotides to bind to the exposed template and thermostable DNA polymerase to join them by phosphodiester bonds

Question 6

what are primers

Answer 6

pieces of single stranded DNA complementary to separated strands

• make out the region to be amplified
• act as a starting point for thermostable DNA polymerase