1. Do Now: 3/16 Period 4: Science & Computers 3 rd period today – get right to work! Period 2: Radiation levels in Tokyo are 20 times above background levels, with recent measurements about 10 μSv/day. Remember the 1% / 5 year cancer threshold we talked about yesterday is 1 Sv. 1. The Tokyo Metropolitan Government has assured residents of Japan’s capital city that the area is still safe. Do you agree? Justify your answer. 2. 100 mSv/hr is considered to be the level “dangerous to human health.” How many hours of exposure at this level will produce the 1% cancer effect?

2. Syllabus Update There is NO CHANGE to the assigned readings. GEL ELECTROPHORESIS is now today’s topic, because of our “breaking science news” day yesterday. GENOMICS / BIOINFORMATICS will no longer be a topic in class. There is NO CHANGE to the assigned readings.

3. GEL ELECTROPHORESIS WHAT IT IS: A method for separating DNA fragments based on their size. WHY IT’S USEFULL: – Isolating important sequences from others – Measuring & mapping DNA sequences – Identification (DNA fingerprinting) HOW IT WORKS: Different sized DNA molecules move through a gel at different speeds, causing them to separate.

5. Virtual Lab http://learn.genetics.utah.edu/content/labs/g el/

6. Short fragments of DNA move faster through gel

7. Gel Electrophoresis in Criminal Investigations Suspect & crime scene DNA collected. PCR with standard primers Cut samples with same restriction enzyme Separate DNA fragments by gel electrophoresis.

8. DNA Paternity Testing Each fragment seen in child sample must come from mother or father. Which gel has the right father?

10. Plasmid Mapping Extra Credit You have been given gel electrophoresis data from the digestion of a fictitious plasmid, pOLY1, with several restriction enzymes. Each enzyme cuts the plasmid in one or two locations. Use the fragment sizes to make a map that shows how the restriction sites are arranged on the plasmid. Indicate the distance between sites in kbp.