[genetics] Barbara McClintock’s most famous accomplishment is the discovery of transposons, or jumping genes. She used phenotypic color variations in corn kernels to study transposable elements. She received the Nobel Prize in Physiology or Medicine in 1983.
[computer science] Grace Hopper invented the first compiler for a programming language, helped develop COBOL (one of the first high-level programming languages), and popularized the term “debugging” after removing a moth from a computer. She was also a US Navy Rear Admiral and an avid teacher, among her many accomplishments.