Topic 6A: Dna Profiling Flashcards
What is DNA profile?
Its a fingerprint of an organisms DNA
Summarise the process of obtaining a DNA profile in 5 steps
- DNA sample obtained
- PCR used to amplify DNA
- Flouresent Tag added
- Gel electrophoresis seperated DNA
- Gel Viewed under UV light
What is the exception for having the same DNA as someone?
Identical twins
What does PCR stand for?
Polymerase chain reaction
What is the purpose od PCR?
To amplify DNA by making millions of copies of specific regions of DNA in a few hours
Describe process of PCR (9)
- reaction mixture containing DNA sample, free nucleotides, primers and DNA polymerase made
- mixture heated to 95°C to break hydrogen bonds between two strands of DNA
– Mixture cooled between 50°C and 65°C primers can anneal to strand
-reaction mixture heater to 72°C so DNA polymerase can work
– DNA polymerase lines up free DNA nucleotides alongside template strand complimentary base pairing means new complimentary strand is formed
– Two new copies of documents of DNA formed and one cycle of PCR is complete
- process repeats/ reheated to 95°C
- exponential amount of DNA
- flourescent tag added
How is gel electrophoresis used to separate DNA? (4)
– DNA placed in the well in a slap of Joe and covered in Papa solution that conducts electricity
– Electrical current passed through gel
– DNA fragments move towards anode because they’re negatively charged
– Short DNA fragments me fast travel further three ciao so DNA fragment separate according to length
Suggest uses of DNA profiling(2)
- determination of genetic relationships i.e. Paternity test
- ised on animals and plants to prevent inbreeding
What is the theory behind unique DNA profiles?(4)
– Danny profiling analyses introns (STR)
– introns are variable
– We have a large number of entrance which have many combinations of Locus
