Genetic Fingerprinting Flashcards
What is 95% of DNA made up of?
Introns
What do introns consist of?
Many variable number tandem repeats
What does VNTRs stand for?
Variable number tandem repeats
What are introns?
The NON-CODING regions of your DNA
What is the probability of two individuals having the same VNTRs?
Very low
What is the relationship between relation and similarity of VNTRs?
The more closely related you are, the more similar the VNTRs are
What is genetic fingerprinting?
The analysis of VNTR DNA fragments
What can genetic fingerprinting be used for?
Used to determine genetic relationships and the genetic variability within a population
What are the 7 stages that the process of genetic fingerprinting can be separated into?
- Collection
- Extraction
- Digestion
- Separation
- Hybridisation
- Development
- Analysis
What size does the DNA sample have to be for genetic fingerprinting?
It can be the smallest sample of DNA
What samples can you collect the DNA from for use in genetic fingerprinting?
Blood, body cells, hair follicles
If the sample of DNA is small then what has to be done?
Then PCR is used to amplify the amount of DNA
Describe the ‘digestion’ stage of genetic fingerprinting:
Once we have a larger sample, restriction endonucleases are added to cut the DNA into smaller fragments. Make sure to select restriction endonucleases that have a complementary active site to the sequence which is found just before the VNTRs. Ensures you have the entire length of the VNTR maintained.
Describe the ‘separation’ stage of genetic fingerprinting:
The DNA samples are loaded into small wells in agar gel. The gel is placed in a buffer liquid with an electrical voltage applied
DNA is negatively charged, so the DNA samples move through the agar gel towards the positive end of the gel.
What charge does DNA have and why?
DNA is negatively charged because the oxygens within the phosphate group are negative