born Feb. 7, 1918, Chicago, Ill., U.S.
died March 29, 1997, Brookline, Mass.
U.S. geneticist.
She received her Ph.D. from Columbia and later taught at Hunter College and Harvard University. Questioning the traditional belief that chromosomal genes are the only apparatus for transmitting genetic information to a cell, she discovered (1953) in the alga Chlamydomonas the existence of a second genetic transmitting system, a gene not located on the alga's chromosomes that controls the cell's sensitivity to the antibiotic streptomycin, and she observed that both male and female Chlamydomonas can transmit the nonchromosomal gene.