Genetically modified food can also be achieved by altering their DNA (or genes) by genetic engineering techniques. This usually involves inserting a gene into the organisms' DNA to create a certain trait.
For example, some corn crops have been genetically modified so that they become more resistant to herbicides and insect pests.
In most countries Genetically Modified foods (GM) as well as foods containing GM source foods have to be labelled by law, giving consumers the choice to use them or not. Agriculturally speaking the opposite of GM foods are "Organic" crops.