DNA Forensics Bio.3.3.1 Interpret how DNA is used for comparison and identification of organisms.

DNA Identification The repeating sequences in noncoding DNA vary between individuals and thus can be used to identify an individual. The DNA is cut into fragments using restriction enzymes. Restriction enzymes recognize and cut specific nucleotide sequences.

DNA identification Scientists copy DNA using the polymerase chain reaction (PCR).

DNA Identification The DNA fragments are separated by size using gel electrophoresis. Largest piece at the top and smallest at the bottom. The resulting pattern of bands is called a DNA fingerprint.

DNA Identification DNA technology provides the tools to manipulate DNA molecules for practical purposes, such as forensic investigation to determine the identity of a criminal, paternity, and forensics. To which family should these soldier’s remains be given?

Electrophoresis use in forensics Evidence from murder trial Do you think suspect is guilty? blood sample 1 from crime scene blood sample 2 from crime scene blood sample 3 from crime scene “standard” blood sample from suspect OJ Simpson blood sample from victim 1 N Brown blood sample from victim 2 R Goldman “standard” 6

Who’s DNA matches the blood stain? Should a person be convicted on DNA evidence alone? Who’s DNA matches the bloodstain?________________

Which child is adopted?

Which of these mother’s biological children has a different father?