Beadle, George Wells (1903–1989)
American geneticist. During his study mutations
in the bread mold Neurospora crassa, he and Edward Tatum found
that genes are responsible for the synthesis
of enzymes and that these enzymes control
each step of all biochemical reactions occurring in an organism. For this
discovery they shared with Joshua Lederberg
the 1958 Nobel Prize in Physiology or Medicine.