Polymerase chain reaction

Question 1

what is the purpose of PCRs

Answer 1

Sometimes there is not enough DNA to test and so the original DNA fragment is split and copied. Each time this process occurs the number of DNA fragments doubles.

Question 2

what are four examples where there is little DNA? (requires PCRs)

Answer 2

1. crime scenes
2. preserved extinct animals
3. detecting viruses early
4. genetic screening

Question 3

what are the three stages of PCRs

Answer 3

1. denaturing
2. annealing
3. synthesis

Question 4

describe the denaturing phase

Answer 4

Temperature is raised to 95 degrees separating DNA into 2 complimentary strands

Question 5

describe the annealing phase

Answer 5

Primers are added and will bind to a single strand of DNA when cooled to 50-60 degrees

Question 6

describe the synthesis phase

Answer 6

DNA polymerase and free nucleotides are added and heated to 72 degrees. DNA polymerase will move in a 3’ to 5’ direction and bind nucleotides together to form a new section of DNA