Genetically Genetically Modified Modified

FoodsFoods

What is a Genetically What is a Genetically Modified (GM) Food?Modified (GM) Food?

Foods that contain an added gene Foods that contain an added gene sequencesequence

Foods that have a deleted gene Foods that have a deleted gene sequencesequence

Animal products from animals fed Animal products from animals fed GM feedGM feed

Products produced by GM Products produced by GM organisms organisms

Why are foods Why are foods genetically modified?genetically modified?

Genetic engineering offers a rapid Genetic engineering offers a rapid and precise method of altering and precise method of altering organisms as compared to traditional organisms as compared to traditional methods that are slow and methods that are slow and inaccurate.inaccurate.

Common GM FoodsCommon GM Foods VegetablesVegetables TomatoesTomatoes PotatoesPotatoes RiceRice CheeseCheese MeatMeat

How is genetic How is genetic modification possible? modification possible?

The components of The components of DNA are the same DNA are the same in all organisms. in all organisms. *Remember this *Remember this from last unit???from last unit???

Sequences that Sequences that code for proteins code for proteins can be moved from can be moved from one organism to one organism to another.another.

How can DNA be moved How can DNA be moved from one organism to from one organism to

another?another?►Find an organism with the desired trait►Isolate the gene sequence that codes for the desired trait►Insert the gene sequence into the genome of the plant cell

How can DNA be moved How can DNA be moved from one organism to from one organism to

another?another?

Its quite simple,

REALLY!!!

How can DNA be moved How can DNA be moved from one organism to from one organism to

another?another?

►Allow the genetically altered cell to grow into a plant

►Allow the plant to reproduce

How can DNA be moved How can DNA be moved from one organism to from one organism to

another?another? A vector can A vector can

carry DNA. The carry DNA. The vector can be a vector can be a pellet from a pellet from a gene gun. gene gun. Viruses and Viruses and bacteria also bacteria also can be utilized can be utilized to transfer to transfer genes.genes.

Watch the clip to demonstrate the process. http://www.dnalc.org/view/15476-Mechanism-of-Recombination-3D-animation-with-with-basic-narration.html

Possible BenefitsPossible Benefitsof GM Foodsof GM Foods

Easing of world Easing of world hungerhunger Development of crops Development of crops

that can be grown in that can be grown in marginal soilmarginal soil

Reduced strain on Reduced strain on nonrenewable nonrenewable resourcesresources Development of Development of

drought resistant cropsdrought resistant crops Development of salt-Development of salt-

tolerant crops tolerant crops Development of crops Development of crops

that make more that make more efficient use of nitrogen efficient use of nitrogen and other nutrientsand other nutrients

Possible BenefitsPossible Benefits of GM Foods of GM Foods

Reduced use of Reduced use of pesticides and pesticides and herbicidesherbicides►Development of Development of

pest resistant cropspest resistant crops ►Reduced herbicide Reduced herbicide

use is better for the use is better for the environment and environment and reduces costs for reduces costs for farmers farmers

Possible Benefits Possible Benefits of GM Foodsof GM Foods

Improved crop qualityImproved crop quality Development of frost Development of frost

resistant crops resistant crops Development of disease Development of disease

resistant cropsresistant crops Development of flood Development of flood

resistant cropsresistant crops Improved nutritional Improved nutritional

qualityquality Development of foods Development of foods

designed to meet specific designed to meet specific nutritional goals nutritional goals

Who makes sure GM Who makes sure GM foods are safe?foods are safe?

Government Government agencies regulate agencies regulate GM foodsGM foods GM foods in the GM foods in the

United States are United States are required to be labeled required to be labeled only if the nutritional only if the nutritional value is changed or a value is changed or a new allergen is new allergen is introduced.introduced.

Possible Risks Possible Risks of GM Foodsof GM Foods

Insects might Insects might develop resistance develop resistance to pesticide-to pesticide-producing GM producing GM crops crops

Herbicide-tolerant Herbicide-tolerant crops may cross-crops may cross-pollinate weeds, pollinate weeds, resulting in resulting in "superweeds""superweeds"

Possible Risks Possible Risks for GM Foodsfor GM Foods

Certain gene Certain gene products may be products may be allergens, thus allergens, thus causing harm to causing harm to human health human health

There may be There may be unintended harm unintended harm to wildlife and to wildlife and beneficial insects beneficial insects

Photo courtesy of T. W. Davies, Cal. Acad. of Sciences.

Time to ThinkTime to Think

• What is a genetically modified food?

• What are some benefits of genetically modified foods?

• What are some possible risks of genetically modified food?