What are GM organisms? A result of technology that has altered the DNA of living organisms (animals, plants or bacteria) A result of technology that has altered the DNA of living organisms (animals, plants or bacteria) Other terms that mean the same thing: Genetically engineered Genetically engineered Transgenic Transgenic Recombinant DNA (rDNA) technology Recombinant DNA (rDNA) technology
How does this differ from Mendel and his peas? GM vs. Selective breeding Selective breeding -slow and imprecise -modification of genes that naturally occur in the organism GM -very fast and precise -can introduce genes into an organism that would not occur naturally!
What is a Genetically Modified (GM) Food? Foods that contain an added gene sequence Foods that contain an added gene sequence Or foods that have a deleted gene sequence Or foods that have a deleted gene sequence Animal products from animals fed GM feed (food) Animal products from animals fed GM feed (food) Products produced by GM organisms Products produced by GM organisms VIDEO #1 VIDEO #1 http://www.teachersdomain.org/resource/tdc02.sci.life.gen.breeding/ http://www.teachersdomain.org/resource/tdc02.sci.life.gen.breeding/ http://www.teachersdomain.org/resource/tdc02.sci.life.gen.breeding/
Why are foods genetically modified? Genetic engineering offers a rapid and precise method of altering organisms as compared to traditional methods that are slow and inaccurate.
Common GM Foods Vegetables Tomatoes Potatoes Rice Cheese Meat Fruit VIDEO #2 http://www.teachersdomain.org/resource/tdc02.sci.life.gen.b tcorn/
Why do it? Examples Rice is not high in essential nutrients Rice is not high in essential nutrientsModification: –ADD (+) daffodil genes and a bacterium = beta-carotene content drastically increased –ADD (+) genes from a french bean = double the iron content. Tomatoes- Introduce genes to increase shelf life. Tomatoes- Introduce genes to increase shelf life.
How is genetic modification possible? The components of DNA are the same in all organisms. Sequences that code for proteins can be moved from one organism to another.
How can DNA be moved from one organism to another? Find an organism with the desired trait (“gene of interest”) Isolate the gene sequence that codes for the desired trait Use restriction enzymes to “cut” the DNA out Insert the gene sequence into the genome of the plant or animal cell
How can DNA be moved from one organism to another? A vector can carry DNA. The vector can be a pellet from a gene gun. Viruses and bacteria also can be utilized to transfer genes.
Possible Benefits of GM Foods Easing of world hunger Development of crops that can be grown in different soil Development of drought resistant crops Development of salt-tolerant crops Development of crops that make more efficient use of nitrogen and other nutrients Faster maturation time Longer shelf life/less waste
Possible Benefits (con’t) Reduced use of pesticides and herbicides ► Development of pest resistant crops ► Reduced herbicide use is better for the environment and reduces costs for farmers
Possible Benefits (con’t) Improved crop quality Development of frost resistant crops Development of disease resistant crops Development of flood resistant crops Save $$ (more profits) Improved nutritional quality Development of foods designed to meet specific nutritional goals VIDEO #3 http://www.teachersdomain.org/ resource/tdc02.sci.life.gen.salmo n/
Who makes sure GM foods are safe? Government agencies regulate GM foods GM foods in the United States are required to be labeled only if the nutritional value is changed or a new allergen is introduced.
Possible Risks of GM Foods Insects might develop resistance to pesticide- producing GM crops Herbicide-tolerant crops may cross- pollinate weeds, resulting in "superweeds"
Possible Risks (con’t) Certain gene products may be allergens causing harm to human health There may be unintended harm to wildlife and beneficial insects Natural selection disrupted Help me! I live in the corn belt!
Possible Risks (con’t) Human Safety Human Safety Creation of biological weapons Creation of biological weapons Access and Intellectual Property Domination of world food production by a few companies and developing countries $$$ and ownership
Possible Risks (con’t) Ethics “Playing God” Tampering with nature by mixing genes among species Labeling Not mandatory in some countries (ex: Canada and the United States) Mixing GM crops with non-GM confounds labeling attempts