1. WHAT IS DNA AND HOW CAN WE USE IT AS EVIDENCE? MAY 30, 2014

2. FIND THE DIFFERENCES BETWEEN THE PHOTOS BELOW

3. AGENDA What is DNA? How is DNA Replicated? What type of evidence is DNA? How can we test DNA? Paternity Testing

4. REMINDERS If you have not taken your test, you must take it today If you know you are failing the course, see me after class Check powerschool to see your grades

8. DNA Deoxyribonucleic Acid

9. DNA Major function is to provide instructions for the cell to make proteins and copies of itself Like a cookbook, with instructions to make each part of the cell and everything it needs to work DNA is heritable (it gets passed on)

10. DNA AS EVIDENCE Circumstantial and Individual Found in: Saliva Semen Blood Skin Urine Hair

11. DNA AS EVIDENCE DNA can be used to link a suspect to a crime, identify a suspect, and identify remains. DNA fingerprinting is the technique used to identify people Most samples found at the scene of the crime are small, and must be amplified to be tested

12. GREEN RIVER KILLER Gary Ridgway

13. HTTP://WWW.BIOGRAPHY.COM/PEOPLE /GARY-RIDGWAY- 10073409/VIDEOS/GARY-RIDGWAY- MINI-BIOGRAPHY-2165764704

14. DNA STRUCTURE Watson and Crick are credited with discovering the structure of DNA

15. DNA STRUCTURE DNA looks like a ladder, but is in the shape of a double helix This allows for improved storage and protection. Without this, mutations would occur frequently.

16. DNA STRUCTURE DNA’s backbone is made up of sugars and phosphates The rungs of the ladder are made up of bases that are in pairs

17. DNA STRUCTURE DNA has four bases that pair together in specific ways: Adenine (A) Thymine (T) Guanine (G) Cytosine (C) A with T and C with G

18. DNA STRUCTURE DNA Replicates by unzipping itself and making new copies (semiconservative replication)

19. DNA FINGERPRINTING Individuals have unique sequences of repeated DNA patterns in the non-coding region of DNA (doesn’t become protein) Variations called polymorphisms Polymorphisms give each person a unique DNA fingerprint Different sequences are seen in the genome of an individual (entire genetic code) Two type of repeats used are VNTR and STR

20. DNA FINGERPRINTING VNTR Variable Number of Tandem Repeats 9 to 80 bases long

21. DNA FINGERPRINTING STR Short Tandem Repeats 2 to 5 bases long Easier to use

22. STEPS IN DNA FINGERPRINTING 1.Extraction 2.PCR 3.Gel Electrophoresis