1. Mutations
Chapter 12-4

2. Unusual Mutations

3. Any change to the genetic code
What are mutations?
Any change to the genetic code
Gene mutations:
A change in one or a few nucleotides in a gene
Chromosomal Mutations:
a change in the number or structure of chromosomes

4. Gene mutations
A) Point mutation: Change of one nucleotide in the genetic sequence. Will change that specific codon.
Substitution
Insertion
Deletion
B) Frameshift mutations: Shift in the reading frame of nucleotides that may cause every codon after the mutation to be different.

5. Chromosomal Mutations
A change in one or a few chromosomes
4 Types:
1) Deletion: Loss of part / all
2) Duplication: Segment is repeated
3) Inversion: Segment is reversed
4) Translocation: Segment breaks off and is reattached

6. Gene mutation: Substitution

7. Gene Mutation: Deletion or Insertion?

8. Gene Mutation:
Deletion
Insertion

9. Now do the practice problems in your notes…

10. Mutation vs. variation
It’s important to remember that losing the function of a gene doesn’t always affect health. For example, most mammals have hundreds of genes that code for olfactory receptors, proteins that help us smell. Losing one of these genes probably doesn’t make all that much difference.
In contrast to variations that cause disease, there are many more examples of variations that are neither good nor bad, but just different—like blood types and eye color. Just like with disease alleles, the process of mutation creates these more neutral variations. But with neutral variations, it can be impossible to tell which allele is the "normal" one that existed first and which is the "mutant"—and the distinction is often meaningless.

11. Unharmful Mutations
Mila Kunis has complete heterochromia. Kate Bosworth has sectoral heterochromia. Angelina Jolie has central heterochromia.
Mila Kunis has complete heterochromia. Kate Bosworth has sectoral heterochromia. Angelina Jolie has central heterochromia.

12. Good mutations?

13. Amoeba Sisters
(7:00)