1. Bell Ringer – 4/22/2014  Happy Earth Day!  Bell ringers are next to the homework bin. You have 5 mins after the bell rings to complete it.

2. Today  Alien Activity wrap-up  Lecture/notes – Mutations (13.3)  Independent work – Study Guide

3. Data Tables for Alien Gene Analysis GENE A DNACAA GGA TAT mRNAGUU CCU AUA Amino AcidsVal - Pro - Ile TraitHairless

4. Mutation  In Biology, a mutation happens when the DNA sequence of an individual is changed  For example, if … ACGTGACCAGGTCCGTGA became ACGTGACCGGGTCCGTGA we would say that the A mutated to a G

5. What causes mutation?  Mutation can be caused by a number of things  Chemicals  Radiation  Ultraviolet light  Viruses  Random chance

6. Types of mutations Two categories of mutations:  Gene mutations (affect 1 gene)  Point mutations  Frameshift mutations  Silent mutations  Chromosomal mutations  Change # or structure of whole chromosome

7. Point mutations  Point mutations affect just one nucleotide (one “point”)  Also called substitution mutations  For example,  THE FAT RED CAT ATE THE RAT could mutate to…  THE FAT RED HAT ATE THE RAT  Even though only one letter (nucleotide) was changed, the sentence doesn’t say the same thing it did before

8. Frameshift mutations  Frameshift mutations involve changing the spacing of the codons  These can either be insertion or deletion mutations  For example…  THE FAT RED CAT ATE THE RAT could mutate to  THE FAT EDC ATA TET HER AT or  THE FFA TRE DCA TAT ETH ERA T  By deleting the “R”, the entire sentence is now complete nonsense.

9. Silent mutations  Some mutations don’t have any effect at all.  For example,  AUG UAC UCG GUA could mutate to  AUG UAC UCU GUA  Where is the mutation?  Did it have an effect?

10. Silent mutations  One of the benefits of having multiple codons for each amino acid.  Mistakes can happen, but they won’t necessarily cause damage.

11. Study Guide  You have the rest of the period to work on your Chpt. 13 study guide (Due Friday)  EXPECTATIONS:  You must stay in your seat  You can work with the people at your table  Voice level should be quiet, no yelling across the room  Ask Ms. D or classmates questions now if you have any!