6.1.3 manipulating genomes

Question 1

what is PCR (polymerase chain reaction) used for

Answer 1

to amplify and produce copies of DNA fragments

Question 2

what does the PCR reaction mixture contain

Answer 2

reaction mixture contains DNA sample, free nucleotides, primers and DNA polymerase

Question 3

what is the function of primers

Answer 3

short pieces of DNA that are complementary to the start of the DNA sample which allows DNA polymerase to bind to it

Question 4

what is the PCR method

Answer 4

heat to 95 degrees to break hydrogen bonds between DNA strands
cool to 50-65 degrees so that primers can anneal to the strands
heat to 72 degrees so that DNA polymerase can line up free nucleotides in complementary base pairing to create 2 copies of each fragment

Question 5

how do we work out how many strands there are at the end of PCR

Answer 5

number of fragments x 2^number of cycles

Question 6

what is electrophoresis