1. Daily Warm-Up Dec. 17th What is a genetic mutation? Homework:
-Read 13.3
Turn in:
-Transcription sheet if haven’t already

2. Mutations and Cancer

3. Genetic Change What is a mutation?
Change in the DNA sequence that changes the genetic message

4. Types of Mutations Point mutation Frameshift mutation
Involves one or a few bases in the DNA sequence
Could be base substitution, insertion or deletion
Frameshift mutation
Changes DNA sequence and causes codons to be read differently
Could be insertion or deletion

5. Base Substitution AGC CTA AGT CTA DNA AGC CTA AGC TTA DNA
One or few bases are replaced by different ones
AGC CTA AGT CTA DNA
UCG GAU UCA GAU mRNA
Ser – Asp Ser – Asp Protein
AGC CTA AGC TTA DNA
UCG GAU UCG UAU mRNA
Ser – Asp Ser – Tyr Protein
May or may not change amino acid at that position
Does NOT cause frameshift No
Change
Change

6. Insertion Addition of one or few bases AUG CCU AUU GCC U
ATG CCT ATT GCC T
AUG CCU AUU GCC U
Met – Pro Iso – Ala
Causes frameshift - changes how codon sequence is read

7. Deletion One or a few bases are removed TGC TCA G TG –T CAG
ACG AGU G AC A GUC
Thr – Ser Thr – Val
Causes frameshift – changes how codon sequence is read

8. Other Terms
Silent mutation- change in DNA that codes for same amino acid
Nonsense mutation- creates a stop codon
Missense mtuation- change in amino acid

9. Chromosomal Mutation
Change in the number of chromosomes or structure of a chromosome

10. Mutagens Factors in the environment that can cause mutations.
Examples?
Pesticides, tobacco smoke, pollutants, X-rays, ultraviolet light

11. Are mutations beneficial or harmful?

12. Polyploidy
Extra sets of chromosomes (ex. 4n)