2 Methods of Developing Organisms With Desirable Traits Selective BreedingCloningGenetic Engineering
3 Selective BreedingThe process of selecting a few organisms with desirable traits to serve as parents of the next generation.Used for thousands of years with various plants and animals.TypesInbreedingHybridization
4 InbreedingTwo individuals that have identical or similar sets of alleles are crossed.Resulting organisms are very similar to their parents.Used to produce breeds of animals with specific traitsEx. Purebred Lab retrievers, German shepherdsIncreases probability that organisms may inherit alleles that lead to genetic disorders.Ex. Hip problems in many breeds of dogs
5 Hybridization Two genetically different individuals are crossed Organism is bred to have the best traits from both parentsEx. Corn with many kernels crossed with disease-resistant cornMost crops grown on farms and in gardens are hybrids.
6 CloningAlthough selective breeding does not allow the breeder to control whether the desired allele will be passed or not, cloning does.CloneOrganism that is genetically identical to the organism from which it was produced.Cloning PlantsSmall part is cut from plant and regrows into a genetically identical plant.
8 Cloning Animals Dolly the Sheep Removed egg cell from one sheep Nucleus in egg cell replaced with nucleus from a six-year old sheepEgg implanted into uterus of 3rd sheepDolly born 5 months later, genetically identical to the six-year old sheep
9 Genetic EngineeringGenes from one organism are transferred into the DNA of another organism.Called “Gene Splicing”DNA molecule cut openGene from another organism is spliced into itUsed toProduce medicineImprove food cropsTry to cure human genetic disorders
10 Genetic Engineering in Bacteria Bacteria used because they reproduce rapidly.Insulin gene spliced into bacteria so that they will produce insulin.
12 Genetic Engineering in Other Organisms Used in plants and other animals.Ex. Human clotting gene inserted into cows. Cows then produce clotting protein in milk, which can then be extracted for humans.Gene TherapyWorking copies of a gene inserted directly into cells of a person with a genetic disorderUsed to correct some genetic disorders
14 DNA Fingerprinting DNA pattern is unique for each individual Used often in crime investigations
15 Human Genome ProjectIdentified the DNA sequence of every gene in the human genome.Involves nearly 60,000-80,000 genesMay lead to new treatments and prevention strategies for many genetic disorders and for diseases such as cancer.
16 Summary QuestionsName three techniques that people have used to produce organisms with desired traits.Why do scientists want to identify the DNA sequence of every human gene?What is genetic engineering? Describe three possible benefits of this technique.Explain how a DNA fingerprint is produced. What information can a DNA fingerprint reveal?