Editorial use only Barbara McClintock (1902-1992), US geneticist, studying maize (Zea mays). McClintock is most famous for her work in the 1940s and 1950s on the genetics of maize. She discovered the moving of genes in chromosomes, by observing patterns of kernel coloration. She named these genes transposable elements, and showed how certain genes were responsible for certain physical traits in the corn. In 1983 she received the Nobel Prize in Physiology or Medicine for her work on mobile genetic elements. Photographed in April 1963, in her laboratory at Cold Spring Harbor at the Carnegie Institution Department of Genetics, New York, USA.