1. Genetic Mutations

2. Genetic mutations Not all are harmful Most cause little/no change
Have to be reproductive cell mutations to repeat in future generations
Somatic mutations not inheritable

3. What are mutations?
Changes in the genetic sequence that affect genetic information
Two types
Gene mutations
Chromosomal mutations
Normal Human Karyotype
Rust’s Disease

4. Examples of mutations
Changes in the DNA sequence that affect genetic information
Normal: Thesunwashotbuttheoldmandidnotgethishat. The sun was hot but the old man did not get his hat.
Translation changed in ribosome: t hes unw ash otb utt heo ldm and idn otg ish at.
Missing letter or base: the sun wsh otb utt heo ldm and idn otg ish at.

5. How do mutations happen?
Environmental agents
UV light, chemicals, radiation
Meiosis
more/less chromosomes
Mistakes in DNA replication

6. What happens when there is a mutation?
The mistake can cause the cell to make an incorrect protein
see a different phenotype than normal ex. White Buffalo
If the mutation occurs in a single type of cell,
it will affect only the cell that carries it ex. Skin cells
If the mutation occurs in a sex cell,
it can be passed to the offspring and affect their phenotype
Mutations can introduce genetic variation
the change can be helpful, harmful or neither

7. Where do they happen? Gene Mutations Chromosome Structural Changes
replication
transcription
translation
Chromosome Structural Changes
Mitosis
Meiosis

8. Gene Mutations Point Mutations Substitute one base for another
involve one nucleotide
single point in a DNA sequence
Substitute one base for another

9. Gene Mutations Frameshift insertion or deletion of a base
shifts entire sequence for translation
different group of amino acids
changes the protein function

10. Review Gene mutations Point mutations – mistakes with 1 nucleotide
Substitution of the wrong nucleotide (nitrogen base) in place of correct one
Frameshift mutations – occur when a nucleotide is either inserted or deleted, altering the trios of nitrogen bases
More severe than point mutations because it effects all of the amino acids in the protein

11. Chromosome Structural Changes
Deletion - loss of all or part of chromosome
- missing genes may prove fatal
Duplication - segment repeated
- usually harmless

12. Chromosome Structural Changes
Inversion - connection broken & sequence reversed - may be fatal
Translocation - non-homologous chromosomes sharing or exchanging information

13. Review Chromosomal mutations
Change in the number or structure of the chromosomes
Deletion
Duplication
Inversion
translocation