1. Breeding New Organisms I don’t mean little brothers or sisters

2. Selective Breeding Example of the Appaloosa Horse One of the oldest ways humans have produced organisms that best suit their purpose Can you think of other examples? –Increase food supply (crop yield) –Improve nutritional values of food –Plants suited for mechanical farming –Drought resistant crops and flowers –Fast race horses In selective breeding individuals with desired characteristics are chosen to produce a new generation

3. Selective Breeding Hybridization –Breeders most important tool –A cross between dissimilar individuals –Example: cross disease resistant plant with high food producing plant

4. Selective Breeding Inbreeding –When a breed is established with the desired character the breeder must maintain it –Inbreeding is the mating of closely related organisms –Insures that the characteristics of the breed are kept for generations Problem: crossing closely related individuals might bring together recessive alleles for a defect Example: blindness and joint deformity in German shepherds and retrievers

5. Mutations A mutation is an inheritable change in genetic information This is where the variation comes from that the breeder selects Remember the definition of phenotype Two types of mutations

6. 1) Chromosomal mutations Changes involving the number or structure of a cell’s chromosomes May result in the change of a genes location May result in the change of the number of copies of a gene May take place during meiosis –Gametes with extra sets of chromosomes may be produced Polyploidy is usually fatal in animals Polyploidy is a healthy condition in many plants Example: banana, wheat, citrus are polyploids

7. 2) Gene mutations Changes involving one or many nucleotides May have dramatic effects on an organism Look at the example on page 199 figure 9-3 Remember protein chemistry, primary sequence, and secondary sequence Remember enzymes and how important the active site is

8. Gene Mutations Change of one nucleotide for another is called a point mutation May change one amino acid in a protein May or may not be important

9. Gene Mutations Addition or deletion of a nucleotide is called a frameshift mutation Can cause tremendous effects in a protein Why’s that? Remember codon’s are read in groups of three A change in the grouping of three, changes the protein sequence