1.2.5 PCR

Question 1

What is PCR a technique for?

Answer 1

the amplification of DNA in vitro

Question 2

How does PCR amplify DNA?

Answer 2

using complementary primers for specific target DNA sequences.

Question 3

What does PCR stand for?

Answer 3

Polymerase Chain Reaction

Question 4

Requirements of PCR (6)

Answer 4

• DNA template
• Primers
• Nucleotides
• pH buffer (maintains optimum)
• Heat tolerant DNA Polymerase
• Thermal cycler machine (to carry out PCR)

Question 5

Uses of PCR

Answer 5

• Forensics: DNA from crime scene can be amplified to determine who was there
• Paternity: DNA can be amplified to prove who is a parent or related
• Diagnosis: Embryonic DNA samples can be amplified to check for genetic disorders

Question 6

PCR step 1

Answer 6

DNA heated to between 92 and 98 degrees in order to denature DNA and break the bonds between strands

Question 7

PCR step 2

Answer 7

DNA cooled to between 50 and 65 degrees in order to allow primers to bind to target sequences

Question 8

PCR step 3

Answer 8

DNA heated to between 70 and 80 degrees for heat tolerant polymerase to replicate the region of DNA

Question 9

What does the thermal cycler do?

Answer 9

allows PCR to be automated