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Genetic engineering (GE) allows scientists to make changes directly to the DNA of a living organism. Changing the DNA, changes the traits. Scientists have looked at all kinds of uses of genetic engineering such as improving the nutrition of the food or how fast it ripens. One area that is getting a lot of interest is improving drought tolerance so plants don't die if there are periods without rain.

There are three uses of genetic engineering that can be found in foods you eat:

  • Insect resistance (Bt) -Insect resistance is obtained by inserting a gene for a protein that is toxic to certain insects.
  • Herbicide tolerance (Ht)- Herbicide tolerant plants have a gene that blocks the effectiveness of herbicides. This allows weeds to be sprayed without killing the crop plants.
  • Disease resistance - Disease resistance is obtained by inserting a harmless gene from a virus. The plants learn to recognize the gene and turn it off. If the plant is later infected with the virus, it continues to turn the gene off. The virus can't reproduce without the gene and the infection is stopped.

Check out these pages about how GE is currently being used in food crops.

Link to page on genetic engineering to fight insects link to cartoon on genetically engineered papaya Link to page on genetically engineered cotton

 

A complete list of approved GE crops is available from the United States Food and Drug Administration. Completed Consultations on Bioengineered Foods Not all of the foods that have been genetically engineered are being sold. GE food crops that are currently sold in the U.S. are soy, corn, rapeseed (canola oil), cotton, papaya, and sugar beets. GE alfalfa is eaten indirectly through animal products(starting after 2011 crop).

Many farmers choose to grow GE crops and are willing to pay extra for GE seeds because the added traits make farming easier. They need to spray and till the soil less often and the chemicals used are less toxic. This chart and the linking pages show the percentage of acres in GE corn, soy and cotton. Adoption of Genetically Engineered Crops in the U.S. (USDA, 2010).

However, not all farmers want to grow GE crops. Check out the page "Should we worry that transgenes spread?" in the controversy section to learn about the spread of pollen from GE plants.