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Advances since Watson & Crick. 13-1 Changing the Living World. Selective Breeding Choosing the “best” traits for breeding Most domestic animals are products of SB. HORSES. Even Cows, Sheep, & Pigs. All Products of Selective Breeding (Artificial Selection). Hybridization.
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13-1 Changing the Living World Selective Breeding Choosing the “best” traits for breeding Most domestic animals are products of SB
Even Cows, Sheep, & Pigs All Products of Selective Breeding (Artificial Selection)
Hybridization Crossing dissimilar individuals to bring together the best traits of both organisms Produces hybrids * Hybrids can be different species crossed together or different types within the same species.
Golden Doodle Puggle Designer breeds or mutts?
INBREEDING Inbreeding = continued breeding of similar individuals (ex. pure breed dogs) Has risks… increases breed’s susceptibility to disease & deformities Golden retrievers - epilepsy Dalmations - hereditary deafness
Increasing Variation Mutations can happen randomly, as in this Scottish fold cat. Cat enthusiasts bred these cats from a single cat with a mutation for the ears. Breeders can increase variation in a population by inducing mutations Mutation = any change in DNA
Biotechnology • Any process that uses our understanding of living things to create a product DNA TECHNOLOGY
Genetic Engineering The process of making changes in the DNA code of living organisms
Genetic Engineering • The human manipulation of the genetic material of a cell. • Recombinant DNA (rDNA)- Genetically engineered DNA prepared by splicing genes from one species into the cells of a different species. Such DNA becomes part of the host's genetic makeup and is replicated.
Genetic Engineering • Genetic engineering techniques are used in a variety of industries, in agriculture, in basic research, and in medicine. This genetically engineered cow resists infections of the udders and can help to increase dairy production.
Genetic Engineering • There is great potential for the development of useful products through genetic engineering • EX., human growth hormone, insulin, and pest- and disease-resistant fruits and vegetables Seedless watermelons are genetically engineered
Genetic Engineering • We can now grow new body parts and soon donating blood will be a thing of the past, but will we go too far? Photo of a mouse growing a "human ear"
Genetic engineering can be accomplished through transformation. Transformation is when a cell takes in DNA from outside the cell. This DNA becomes part of the cell’s DNA. This can be accomplished with the help of bacteria.
Bacterial Transformation The changing of one strain of bacteria into another strain.
Plasmid: a circular piece of DNA found in bacteria F+ bacterium contains a plasmid F- bacterium does not contain a plasmid
Steps of Bacterial Transformation 1-Remove the plasmid from the bacterium.
Steps of Bacterial Transformation 2-Isolate the gene of interest. A gene of interest is a piece of DNA that codes for a protein we want more of
Steps of Bacterial Transformation 3-Open the plasmid by cutting it with a restriction enzyme This leaves “sticky ends” Which need to be the complement of the sticky ends left on the DNA fragment you want to insert.
Sticky Ends The restriction enzyme EcoR1 cuts the DNA at the sequence GAATTC, between the G and the A
Steps of Bacterial Transformation 4-Insert the gene of interest
Steps of Bacterial Transformation 5-Insert the plasmid with recombinant DNA into a new bacterium. Recombinant DNA: DNA produced by combining DNA from different organisms
Steps of Bacterial Transformation 6-The bacteria reproduces itself and the plasmid. All descendants express the inserted gene
Other Types of Transformation • Plants: -Use bacteria that insert their plasmid into plant cells -removing cell walls sometimes allows plant cells to take up foreign DNA on their own
Other Types of Transformation • Animals: -Many egg cells are large enough that DNA can be directly injected
Genetically Engineered Products
Production of Human Insulin • Insulin regulates the blood sugar level. • The gene for human insulin is inserted into yeast or bacteria, from which large quantities of the human insulin are manufactured http://publications.nigms.nih.gov/genetics/images/ch1_diagram.gif http://www.ingenious.org.uk/media/4.0_SAC/webimages/1032/1/10321271_3.jpg
Golden Rice • Undernourished people in poorer countries may have blindness caused by a lack of vitamin A • Contains beta-carotene, which forms Vitamin A
Golden Rice • Genes for making beta-carotene are taken from daffodils and inserted into the genome of rice http://www.bairesbiotec.org.ar/images/speake1.jpg http://www.jewishworldreview.com/toons/varvel/biotech.protest.gif
Recombinant Bovine Growth Hormone • rBGH is a genetically engineered version of a hormone, which is found in the pituitary gland of cows and controls milk production • rBGH can increase cows’ milk production by as much as 20-30% http://www.healingdaily.com/detoxification-diet/rBGH.jpg http://simple.wikipedia.org/wiki/Image:Milk_glass.jpg
Spider Silk • Elastic, light weight fiber 5 times stronger than steel • One method involves inserting the gene from a weaving spider into a fertilized goat egg. The resultant “spider-goat” produces milk that can be manufactured into strong fibers. http://www.chm.bris.ac.uk/motm/spider/goat.jpg
Spider Silk • To make flak jackets, rope, textiles, sutures, artificial tendons, and bandages for burn victims
Glowing Organisms • Genes that make jellyfish glow are inserted into other organisms • The organism glows under UV light http://www.fluorescentpets.com/prod31.jpg
Gene causes these mice to glow in the dark. Normally, the gene is found in jellyfish.
Bt Crops • Bt is a bacterium that is toxic to some insects. In the lab, the gene that produces the toxic effect is inserted into the DNA of plants • Bt crops produce an insecticide protein thousands of times more powerful than the chemical spray insecticides
Transgenic Organisms : Any organism whose genome incorporates and expresses genes from the same or a different species Genetically modified products: Altering the DNA of an organism to get it to express different traits.
TransgenicOrganisms Contains genes from other species Microorganisms (bacteria) Animals (mouse; medical uses) Plants (agricultural uses) *GM Crops
DNA Technologies • DNA technologies allow scientists to identify, study, and modify genes. • Forensic identification is an example of the application of DNA technology.
Applications of DNA Technology • DNA fingerprinting in forensics • Human Genome Project