Polymerase Chain Reaction

Question 1

PCR method of DNA replication

Answer 1

1. PCR uses heat to separate double stranded DNA (not helicase)
2. Two separate strands used as template strands
3. New strand built by specialized polymerase can with stand high heat (TAQ polymerase)
4. TAQ needs a primer to begin
5. Temperature is decreased at this point so primers can anneal to opposite ends of template strand
6. Temperature increases again for polymerase to work
7. When the new copies are made the process repeats

Question 2

Uses for PCR ?

Answer 2

Forensics- only need one cell that contains some genetics info

Medical diagnosis- early detection of HIV before antibodies are present

Genetic research- fossil remains can contain enough genetic info to decide if two species are related

Question 3

Polymorphism

Answer 3

Any difference in DNA that can be detected between individuals can be present in both coding and non coding regions

Question 4

RFLP analysis

Answer 4

Compares different lengths of DNA fragments made by restriction endonucleases

Large quantities of DNA will smear after gel electrophoresis

Question 5

Steps of RFLP analysis?

Answer 5

1. Gel placed on nylon membrane and chemical added to denature double stranded DNA into single stranded
2. Electric current used to cause single stranded DNA to migrate onto nylon membrane (southern blotting)
3. Nylon membrane soaked in solution containing complimentary radioactive probes which anneal and certain regions
4. Nylon then placed against x Ray film and an autos diagram produced when probes burn image into x Ray film

Question 6

What is PCR?

Answer 6

Amplification of a DNA sequence by repeated cycles of strand separation and replication