1. Gene Mutations

2. Mutation Mutation – changes in the genetic material. Gene Mutations
Chromosomal Mutations

3. Gene Mutation Point mutation: changes in one/few nucleotides
Substitutions: one base is changed to another
only affects one amino acid

4. Gene Mutation Frameshift mutations: shift codon reading frame
Insertions: base is inserted into the DNA
Deletion: base is removed from DNA
every amino acid that follows the point is changed
Proteins cannot perform their normal functions

5. Chromosomal Mutation
Changes in the number or structure of chromosomes.
Change the location of genes and the number of copies of a gene.
Deletion: loss of all or part of chromosome
Duplication: produce an extra copy of chromosome part
Inversion: reverse the direction of part of chromosomes
Translocation: part of one chromosome breaks off and attaches to another

6. Chromosomal Mutations

7. Significance of Mutations
Many have no effect
Some produce defective proteins that disrupt normal activity
Source of genetic variability
Polyploidy: organism has an extra set of chromosomes
plants are often larger and stronger
bananas and citrus fruits

8. Gene Regulation
DNA regulatory sites: proteins bind to regulate transcription
controls if a gene is turned on or off

9. Bacteria Gene Regulation
operon - a group of genes that work together
lac operon allows lactose to be used as food
lac genes are turned off by repressors and turned on by the presence of lactose
lac repressor binds, the operon is off & transcription doesn’t occur
Add lactose, the repressor changes shape and falls off the operator
Transcription can occur

11. Development & Differentiation
During development, cell differentiate - become specialized in structure and function
Hox genes control embryos’ cell differentiation
Mutations can completely change development