Genetically Genetically Modified Modified

FoodsFoods(GM or GMO (GM or GMO

foods)foods)

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

Common GM FoodsCommon GM Foods VegetablesVegetables CornCorn SoybeansSoybeans TomatoesTomatoes PotatoesPotatoes RiceRice CheeseCheese MeatMeat

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

The components The components of DNA are the of DNA are the same in all same in all organisms. organisms.

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

►Allow the genetically altered cell to grow into a plant

►Allow the plant to propagate

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.

Possible BenefitsPossible Benefitsof GM Foodsof GM Foods

Easing of world Easing of world hungerhungerDevelopment of Development of

crops that can be crops that can be grown in marginal grown in marginal soilsoil

Critics say this Critics say this benefit is used to benefit is used to market GM crops, market GM crops, since the companies since the companies are not working to are not working to alleviate hungeralleviate hunger

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 pest resistant cropscrops

►Reduced herbicide Reduced herbicide use is better for use is better for the environment the environment and reduces costs and reduces costs for farmers for 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

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.

Possible Risks Possible Risks of GM Foodsof GM Foods

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

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

May increase May increase herbicide use herbicide use because of pesticide because of pesticide tolerant GM cropstolerant GM crops

Should GM foods be Should GM foods be labeled?labeled?

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

United States are United States are not required to be not required to be labeled. labeled.

Who is growing (and Who is growing (and eating) GM crops?eating) GM crops?

In 2003, countries that grew 99% In 2003, countries that grew 99% of the global transgenic crops of the global transgenic crops were the United States (63%), were the United States (63%), Argentina (21%), Canada (6%), Argentina (21%), Canada (6%), Brazil (4%), China (4%), and Brazil (4%), China (4%), and

South AfricaSouth Africa (1%). (1%).

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