1. Mutations
Chapter 12.4

2. Mutation
A result of changes in individual genes or the gene arrangements on chromosomes
Original code (order of bases) is changed
2 different kinds
Gene mutation
Chromosome mutation

3. Gene Mutations Mutations occurring within a gene
Usually a letter change, removal, or addition
Three different types:
Deletion
Insertion
Point mutation

4. Gene deletions and insertions
Gene deletion  nucleotide is left out
Gene insertion  an extra nucleotide is added
These are called frame-shift mutations
causes the order of bases to switch, which causes change in codons, which in turn changes amino acid sequence

5. Point mutations
Point mutation  a base is substituted for one other base
Will only affect one amino acid in the protein

6. Point Mutation
- Deletion

7. Chromosome Mutations
Mutations that occur within a chromosome or between chromosomes
4 different types:
Deletions
Duplications
Inversions
Translocations

8. Deletions and Duplications
Chromosomal deletion  part of a chromosome are removed
Chromosomal duplication  part of a chromosome is duplicated

9. Inversion and Translocation
Chromosomal inversion  portion of a chromosome is reversed
Chromosomal translocation  part of one chromosome attaches to another, different chromosome

11. Mutagens Mutagen an agent that causes a mutation
environmental factors such as radiation, heat, and chemicals

12. Passing On of Mutations
Mutations that occur in “body cells” do not get passed on to offspring
Mutations that occur in “sex cells” do get passed on to offspring

13. Mutation and Evolution
Mutations could cause a new allele for a characteristic
Mutations could also be the fuel that drives evolution
individuals that underwent mutations may be better suited for survival than the original