1. 13.1 Changing the Living World

2. 1. Selective Breeding
Allowing only those animals with desired characteristics to reproduce
Example: breeding dogs

3. 2. Selective Breeding Luther Burbank:
Developed disease-resistant potatoes
Went on to develop 800+ varieties of plants

4. 3. Selective Breeding Hybridization:
Crossing dissimilar individuals to bring out the best of both organisms
Hybrids are produced
Burbank’s plants: disease resistant and food producing

5. 4. Selective Breeding Inbreeding
Continued breeding of individuals with similar characteristics
Breeds of dogs are maintained through inbreeding
Serious problems can arise
Two recessive alleles for a disease can be passed on more easily
Joint problems and blindness

6. 5. Increasing Variation
Variation can be introduced by inducing mutations
Induce mutation through radiation and chemicals
New Bacteria
Oil “eating” bacteria
Caused variation which allowed some bacteria to digest oil
Cleaning of oil spills

7. 6. New plants Polyploidy Causes chromosomes to not split apart
Creates 3N or 4N individuals
Usually fatal, but plants survive
These plants can be stronger and larger than normal, diploid plants

8. 13.4 Applications of Genetic Engineering

9. 1. Transgenic Organisms Transgenic: contains genes from other species
Tobacco plant with gene to cause it to fluorescently glow

10. Transgenic Organisms

11. 2. Transgenic Organisms Microorganisms:
Bacteria are commonly used because they are small and easy to grow

12. 3. Transgenic Organisms Microorganisms
Can be used to produce insulin, growth hormone and clotting factor easily
Human genes to produce these compounds were inserted into the bacteria

13. 4. Transgenic Organisms Animals
Mice with immune systems similar to humans
Allows scientists to study the effects of diseases on the immune system
Livestock with growth hormone to grow larger and faster

14. 5. Transgenic Organisms Plants
52% of the soy beans and 25% of corn were genetically modified
Contain natural insecticide so the crop does not need to be treated with pesticides
Resistant to weed-killing chemicals
The plant can still grow while weeds are killed

15. 6. Cloning
producing a genetically identical individual from a single cell
1997 Ian Wilmut cloned a sheep and named her Dolly

16. 7. What happens during cloning?
Nucleus from one cell is put into an egg cell where the nucleus has been removed
The cell begins to divide and produce a new individual, genetically identical to the donor

17. 8. Cloning One hope for cloning is to help endangered species
Controversial because cloned animals may have genetic defects and health problems