Herbicide tolerant crops can withstand a certain chemical herbicide, so that when the crops are sprayed, along with the weeds, in order to kill the weeds, the crops are not harmed (University of California Seed Biotechnology Center, n.d.).
Example: Soybean
Insect resistant crops have been genetically modified so that when certain insects eat them, the insects die. These are also known as BT crops (University of Arizona, 2017).
Examples: Cotton, Maize
The gene for ACP thioesterase, which comes from a California Bay Tree, the Umbellularia Californica, is injected into canola oil, which creates high levels of laurate. Laurate is a saturated fatty acid with a 12-carbon atom chain that makes the canola oil better suited for food manufacturing and to increase the oil quality (Phillips, 2008).
Example: Canola
Virus resistant GMOs are created by injecting a coat protein gene from the virus, which creates the shell of the virus, in order to protect the genetic material (World Health Organization, 2017).
Example: Genetically modified papaya is resistant to Papaya Ringspot Virus (PRSV), which is a plant virus spread largely by aphids, which are small sap-sucking insects (Gonsalves, Tripathi, Carr, & Suzuki, 2010).
Sources
Image by CESAR AUGUSTO RAMIREZ VALLEJO from Pixabay. https://pixabay.com/photos/nature-fruit-tropical-papaya-2548846/
University of California Seed Biotechnology Center (Ed.). (n.d.). Herbicide Tolerance. Retrieved from http://sbc.ucdavis.edu/Biotech_for_Sustain_pages/Herbicide_Tolerance/
University of Arizona. (2017, October 10). Pest Resistance to Biotech Crops Surging. Retrieved from https://phys.org/news/2017-10-pest-resistance-biotech-crops-surging.html
Phillips, T. (2008). Genetically Modified Organisms (GMOs): Transgenic Crops and Recombinant DNA Technology. Retrieved from https://www.nature.com/scitable/topicpage/genetically-modified-organisms-gmos-transgenic-crops-and-732/
World Health Organization. (2017, February 15). Frequently asked questions on genetically modified foods. Retrieved from https://www.who.int/foodsafety/areas_work/food-technology/faq-genetically-modified-food/en/
Gonsalves, D., Tripathi, S., Carr, J., & Suzuki, J. (2010). Papaya Ringspot Virus. Retrieved from https://www.apsnet.org/edcenter/disandpath/viral/pdlessons/Pages/PapayaRingspotvirus.aspx