Forensic Science DNA Analysis Review/OJ Case

exactly what the title said.

What is DNA & why is it important to forensic scientist/investigator?

Individualized genetic code/directly identifies people

What are the 3 parts of a DNA nucleotide

Sugar, Phosphate, Nitrogen Base

According to the rules of base pairing, how does DNA pair

Adenine + Thymine / Guanine + Cytosine

5 examples of nucleated body cells with DNA

hair, white blood cells, skin, saliva, semen

Difference between coding and noncoding regions of DNA

Coding - codes for proteins/ Non Coding - doesn’t

How can DNA profiling (fingerprinting) be used to identify people

1.extracting DNA for sample 2. Amplifying specific DNA regions 3.Analyzing size and number of DNA fragments 4. Comparing DNA profile to reference 5. Determining a match or exclusion

What is restriction enzyme

Cuts DNA at recognition sites

What is RFLP

Restriction Fragment Length Polymorphism

During gel electrophoresis, what happens to DNA

separated by size of DNA

What is PCR, how is it useful to forensic scientists

Plymerase Chain Reaction, allows for amplification on small amounts of DNA

What is the job of DNA polymerase

synthesise new DNA strands using existing template

Steps in PCR process

1. Denaturation - DNA heated

2. Annealing - primers bind to target

3. Extension - DNA polymerase extends the primers

What are advantages to PCR

Amplify small DNA, fast process, highly sensitive, analyzes deguded samples

What is short tandem repeat STR

short severance of DNA that’s repeated

STR advantages

highly valuable for identification

CODIS

Combined DNA Index System - FBI database

Compare/Contrast Nuclear DNA and Mito DNA

Nuc - nucleus Mito - mitochondira

Nuc - both parents Mito - mother

DNA fragments can be sorted according to size with what technique

Gel Electrophoresis

Watson and Crick (and Franklin)

Discovered double helix shape for DNA

Alec Jeffreys

Developed DNA fingerprinting

Factors that affect DNA evidence at crime scene

Environmental, contamination, degradation

Properly collected DNA evidence, how?

documented, minimize contamination, store in appropriate facility - CHAIN OF CUSTODY

what are buccal cells and how are they used to obtain DNA samples

Cheek swab - cells from inside cheek - is cells, DNA

OJ Simpson

Suspect

Nicole Brown Simpson

Victim

Ronald Goldman

Victim

Mark Fuhrman

Police Officer on Scene (the racist one)

Marcia Clark

Prosecutor

Chris Darden

Prosecutor

Johnnie Cochran

Defense Lawyer - Dream Team

F. Lee Bailey

Defense Lawyer - Dream Team

Alan Dershowitz

Defense Lawyer - Dream Team

Barry Scheck

Defense Lawyer - Dream Team

Robert Kardashian

Defense Lawyer - OJ’s friend - more for publicity