Genetically modified (GM) foods generally refer to food products derived from transgenic plants such as canola or rice. GM crops have been produced to express a desired trait, such as resistance to herbicides or higher levels of vitamins. Traditional breeding involves selecting the most suitable plants, and removing weak plants so only the fittest survive to set seeds and the next generation will be fitter. It also involves the crossing of different crops to produce desirable phenotypes in the offspring, and this is a form of genetic modification as a gene transfer occurs. This is done through trial and error, and takes some time.
Transgenic plants refer to genetically engineered plants that have had new genes introduced into their genome in a laboratory so they express a desired phenotype, which is much quicker and more accurate than traditional techniques. The specific gene(s) can be transferred into the plant, which saves a lot of time compared to the traditional breeding techniques using trial and error. There are two common processes by which new genes are introduced, one by firing the gene sequence into the plant cell using gold coated particles or by horizontal gene transfer using a vector such as
agrobacterium tumefaciens
.