Keywords: Genetic corn.jpg An ear of corn the kernels are varied in color Researchers suggest that retroviruses have additional stretches of DNA that act as switches turning on genes when inserted next to them in the cell's chromosomes Similar activation of genes causes the variation in pigmentation of these corn kernels Topics/Categories Food and Drink Science and Technology -- Genetics Type Color Photo Source National Cancer Institute Linda Bartlett Photographer 2002 1980 Reuse Restrictions None - This image is in the public domain and can be freely reused Please credit the source and/or author listed above Linda Bartlett Photographer PD-USGov-HHS-NIH Media from National Cancer Institute Visuals Online Images uploaded by Fæ Food with black background Fruit on black background 1980 photographs Corncobs |