1. Chapter 13.3 (Pgs. 372-376): Mutations

2. Mutations Are heritable changes in genetic information
Have two major types:
Chromosomal mutations
Point mutations
Can be harmful or beneficial

3. Chromosomal Mutations
Involve changes in the number or structure of chromosomes
Deletion
Loss of all or part of a chromosome
Duplication
Produces an extra copy of all or part of a chromosome
Inversion
Reverses the direction of parts of a chromosome
Translocation
Part of one chromosome breaks off and attaches to another chromosome

4. Point Mutations
Are mutations that involve changes in one or more nucleotides
Occur at a single point in the DNA sequence
Can cause changes to occur further along the DNA molecule from the initial mutation

5. Point Mutations Substitution Sickle Cell Anemia
One nucleotide is changed to a different nucleotide
Sickle Cell Anemia

6. Point Mutations Insertion or Deletion Huntington’s Disease
One nucleotide is inserted or removed from the DNA sequence
Huntington’s Disease
Muscular Dystrophy

7. Point Mutations Frameshift
Mutations that change the “reading frame” of DNA
Change the sequence of DNA from the initial point of mutation

10. Causes of Mutations Include naturally-occuring errors
Can occur during replication
Include chemical and physical agents in the environment, called mutagens
Chemicals
Radiation

11. Effects of Mutations Can be harmful Can be helpful
Change protein structure or gene activity in a negative way
Sickle cell anemia
Can be helpful
Change protein structure or gene activity in a positive way
Increase disease resistance
Create better physiological function
Some mutations have no effect at all