science · 07 July 1861 · 163 years ago
birth
Born 7 Jul 1861; died 4 May 1912 at age 50.
American geneticist who was born in the year that the Civil War began, and despite difficult times and limited women's educational opportunities, became one of the first American women to achieve recognition for her contributions to scientific research. As a cell biologist and geneticist, her great contribution to science was as one of the first scientists to find that sex is determined by a single difference between two classes of sperm - the presence or absence of an X chromosome.