Week 8 DNA Fingerprinting Flashcards
What is DNA fingerprinting?
A technique used to identify individuals of the same species based on differences in their DNA.
Why is DNA fingerprinting more accurate than other methods?
It uses unique DNA sequences which vary more precisely between individuals.
What percentage of DNA differs from person to person?
Only 0.1% (1 in 1000 bases).
What is RFLP?
Restriction Fragment Length Polymorphism – uses restriction enzymes to cut DNA at specific sites and analyze fragment lengths.
What is gel electrophoresis used for in DNA fingerprinting?
To separate DNA fragments by size, producing a banding pattern unique to each individual.
What is a Southern Blot?
A technique to transfer DNA from a gel to a membrane and detect specific sequences using a probe.
What are VNTRs?
Variable Number Tandem Repeats – short sequences repeated a variable number of times between individuals.
What is PCR?
Polymerase Chain Reaction – a technique used to amplify specific DNA sequences.
What are the key steps in PCR?
Denaturation (94°C), Annealing (50–60°C), and Extension (72°C), repeated for ~30 cycles.
What are major applications of DNA fingerprinting?
Forensics, paternity testing, disease diagnosis, genealogy, and crime scene investigation.
How was DNA used after the 9/11 attacks?
DNA profiles were used to match tissue samples from victims to family reference samples using STR, mtDNA, and SNPs.
How is mtDNA used in forensic analysis?
It’s maternally inherited and useful for old or degraded samples where nuclear DNA is absent.
What does Y-chromosome analysis help with?
Tracing male lineage and identifying male contributors in mixed DNA samples.
How is DNA fingerprinting used in nonhuman analysis?
To verify plant or animal identity, trace food origin, and detect illegal hunting or fraud.
Give an example of nonhuman DNA forensic use.
Matching bear blood at a den to prove illegal hunting in Pennsylvania.
