Genetically modified organisms (GMOs) can be engineered in several ways to alter plant traits. Some common applications include making crop plants resistant to herbicides, allowing farmers to spray fields without damaging crops. Corn, soybeans, and cotton in the US are often engineered for herbicide resistance. GMOs are also used to improve crop quality, increase nutrient levels, and produce pharmaceuticals and vaccines in plants. However, the ethics and impacts of GMO technology are debated, with concerns about environmental effects, corporate control of seeds and genes, and impacts on developing countries.