1. Chapter 13 Changing the Living World

2. Selective Breeding and Hybridization  Selective Breeding  Allowing only those organisms with desired characteristics to reproduce  Domestic animals (purebreds) such as dogs and horses are the result of selective breeding  Hybridization  Crossing dissimilar individuals to bring together best of both organisms  Often hardier than either parent

3. Inbreeding  Continued breeding of individuals with similar characteristics  Maintains characteristics  Dog and horse breeders use this method  Risks:  Organisms are genetically similar  Chance of recessive alleles for genetic defects more prevalent  Blindness and joint deformities in dogs  Foal death in Arab foals

5. Increasing Variation  Selective breeding not possible without wide variations in natural populations  Sometimes want more variations than are possible  Can increase genetic variation by inducing mutations (the ultimate source of variation)  Can occur spontaneously  Can use radiation and chemicals to produce them

6. Producing New Kinds of Bacteria  Induced mutations work in bacteria as well  Used to produce hundreds of strains of helpful bacteria  Includes oil eating bacteria- used in oil spill cleanup

7. Warm Up  Define selective breeding……

8. Science of Dogs  Netflix  National Geographic - Science of Dogs

9. Chapter 13 Manipulating DNA

10. Tools of Molecular Biology  Genetic engineering:  Making changes in the DNA code of living organisms  Uses:  DNA extraction  Cutting DNA  Separating DNA

11. Tools of Molecular Biology  DNA Extraction:  Simple chemical procedure  Cells opened  DNA separated from other cell parts  Cutting DNA  Use restriction enzymes  Cuts DNA at specific sequences  DNA from one organism that is spliced into the DNA of another is called recombinant DNA

12.  Separating DNA  Use gel electrophoresis  Mix DNA fragments placed in gel  Power source turned on  DNA molecules have negative charge  So move to positive end  Smaller fragments travel faster than larger ones  Used to compare gene composition of two individuals or separate one gene from another

13. Which DNA strands come from the same person? 1 2 3 4 5 6 7 8 9 10 11 12

14. Restriction Enzyme Animation  http://www.dnalc.org/ddnalc/resources/restricti on.html http://www.dnalc.org/ddnalc/resources/restricti on.html

15. Cell Transformation  Changing DNA then putting it back into a living cell and having it work  This process was done by a scientist named Griffith.

17. Transforming Bacteria  Foreign DNA spliced into circular DNA of bacteria known as plasmid  Has DNA sequence that promotes plasmid replication  Have genetic markers that let researchers identify which bacteria carry the recombinant DNA and which ones don’t

19. Warm Up  DNA from one organism that is spliced into the DNA of another is called…  A. Combination DNA  B. Repolymerized DNA  C. Recombiant DNA  D. Transformed DNA

20. Chapter 13 Applications of Genetic Engineering

21. Genetic Engineering  Can the genes from plants and animals work in each other?  Yes  The basic mechanisms of gene expression are shared by both plants and animals

22. Transgenic Organisms  Transgenic- contain genes from other species  Same techniques are used to insert DNA from one species into another Species 1 Species 2

23. Transgenic Microorganisms  Because they grow quickly they are used to produce many beneficial substances:  Insulin  Growth hormone  Clotting factor

24. Transgenic Animals / Plants  Animals  Used for:  Study of genes  Improve food supply  Produce faster growing, leaner meats  Study of diseases on human immune system  Plants  Produce natural pesticides  Resistant to weed killers

28. Cloning  A member of a population of genetically identical cells  Microorganisms easy to grow  More difficult in multicellular organisms

29. Cloning  1997  Ian Wilmut cloned a sheep  Procedure:  Nucleus of egg cell removed  Body cell from donor is fused with the nucleus  Fused cell begins to divide  Embryo placed in uterus of foster mother  Animals that have been cloned:  Cows  Pigs  Mice  Sheep  Controversial  Animals may suffer  Genetic deformities  Health problems  Humans  Unethical !!!!!