Folding fact #103
1910 Thomas Hunt Morgan proved that genes are carried on chromosomes, establishing the basis of modern genetics. With his co-workers, he pinpointed the location of various fruit fly genes on chromosomes, establishing the use of Drosophila fruit flies to study heredity. Morgan's group also demonstrated the existence of sex-linked genes, and over the next ten years expanded the idea to other trait linkages, using "crossing-over" to help determine the location of genes.