DNA Profiling Flashcards
What are DNA profiles?
Some of an organism’s genome (all the genetic material in an organism) consists of repetitive, non-coding base sequences - sequences that don’t code for proteins and repeat over and over.
The number of times these non-coding sequences are repeated differs from person to person, so the length of these sequences in nucleotides differs too
The number of times a sequence is repeated at different, specific places (loci) in a person’s genome (and so the number of nucleotides there) can be analysed using electrophoresis. This creates a DNA profile
The probability of two individuals having the same DNA profile is very low because the chance of two individuals having the same number of sequence repeats at each locus in DNA is very low
Use of DNA profile in forensic science
Use DNA profiles to compare samples of DNA collected from crime scenes (e.g. DNA from blood, semen, skin cells, hair) to samples of DNA from possible suspects
PCR is used to amplify multiple areas of DNA
The PCR products are run on an electrophoresis gel and the DNA profiles produced are compared to see if any match (i.e. have the same same pattern of bands on the gel)
Compare bands of DNA sample of person with known DNA sample(from the crime scene)
Use of DNA profiles in medical diagnosis
Unique patter of several alleles, could link to genetic disorders
