LIFESCI 15 Lecture Notes - Lecture 9: Dna Profiling, American And British English Spelling Differences, Asteroid Family
Document Summary
Real fingerprints not left behind in many crimes. Can prove innocence of people unjustly convicted. Dna = long sequence of letters that carry the info of how to build molecules for the body. Different enough (3 million different based pairs) Thm #1: on average, individuals differ in their dna sequence at 0. 1% of their bases: 3 million difference out of 3 billion base pairs. Short tandem repeats: repeating units 4-5 nucleotides long. Thm #2: for an str locus, many (2 or 3 dozen or more) alleles exist within the population, but each individual can only have 2 of them. Comparing str loci: choose 6 features for which individuals vary a lot, compare dna sample for those 6 features. If they are the same at all of them, it matches. Creating a dna fingerprint: dna fragment containing each str region is amplified using pcr.
