1. Section 13.3

2.  The sequence of bases in DNA are like the letters of a coded message.  What would happen if one or a few of those letters changed accidentally, altering the message?  What effects would you predict such changes would have on genes and the polypeptides for which they code?

3. A permanent change of the nucleotide sequence of the DNAof an organism.

4. - Chromosomal mutations - Point mutations

5.  A mutation involving a long segment of DNA.  These mutations can involve ◦ deletions ◦ insertions ◦ Inversions ◦ translocations  In some cases, the deleted sections may attach to another chromosome, disrupting both the one that loses the DNA and the one that gains it.

6.  A mutation involving a single nucleotide base ◦ substitution ◦ insertion ◦ Deletion

7. Substitutions – can affect one amino acid. - may have no affect …….It all depends on what is substituted Examples: CCC  CCACCC  ACC proline  prolineproline  threonine

8. Insertions / Deletions  These are referred to as frameshift mutations because everything downstream of the mutation in affected. a. Insertions b. Deletions THE CAT ATE THE DOG THE CAT TAT ETH EDO G (Insertion of extra T) THE CAA TET HED OG (Deletion of T)

9. Mutations may be artificially or naturally induced by Mutagens, including ◦ Pesticides ◦ Tobacco smoke ◦ Environmental pollutants ◦ Radiation Outcome may be ◦ Good ◦ Bad ◦ Neutral Click Smog for video