1. Aim: How do scientists identify people using DNA Fingerprinting?

2. LO: SWBAT explain how scientists identify people using DNA fingerprinting
DN: Why do we fingerprint people? What is it useful for?
HW: read pp , page 339 #18-19
Fri: Review Book- Respiration
Quarterly- Next Wed/Thurs

3. Why do we Fingerprint?
So we can identify people

4. Why is DNA used to identify people?
People have different DNA base sequences, therefore each individual will have a different DNA fingerprint.

5. Genetic Markers: ATTGCCTAGG - Individual 1 ATTGCCATGG - Individual 2
particular stretches of ____ that are _________ among individuals.
DNA
variable
Our __________ regions are highly _________ from one individual to another and serve as good ________________ to be used for DNA fingerprinting.
noncoding
variable
genetic markers

6. How do scientists make a DNA Fingerprint?
Investigators need to find some ____ of the perpetrator.
DNA
Where can the investigators find the DNA?
Blood
Hair
Nails
Skin

7. Only a small amount of DNA is needed!
Polymerase Chain Reaction: PCR
The sample of DNA is amplified (___________)
multiplied

8. PCR Animation

9. – + Gel Electrophoresis
Amplified DNA is cut with specific __________________.
2) DNA segments are loaded into wells in a porous ____.
3) Electric current is passed through the gel making one side of the gel __ charged and one side __ charged.
restriction enzymes
gel – +

11. Gel Electrophoresis
DNA is ___________ charged & moves through the gel to the _________ side.
5) Smaller segments move _______ & ________ than the larger segments.
negatively
positive
faster
farther

13. Gel Electrophoresis
6) The gel is then ________ so we can see the DNA ________ patterns.
stained
banding
Result: The smaller segments of DNA are found closer to the _________ end than the larger segments.
positive

15. **Separates DNA segments
according to _____.
SIZE

16. - + Gel Electrophoresis __ __ __ __ __ __ __ __ __ __
DNA Suspect A Suspect B Suspect C
from CS
__ __ __ __
__ __
__ __ __ __ +

17. DNA Fingerprint Questions:
What is the charge of DNA?
Where would we find the smallest DNA fragments, closer to the + end or the – end?
Why do we get different banding patterns for each individual?
4) Which suspect was at the crime scene?