7. Ruth Ella Moore (1903-1994)
By completing a doctorate in bacteriology, Ruth Ella Moore became the first African-American woman to earn a PhD in the life sciences. She was also appointed Head of the Department of Bacteriology at Howard University College of Medicine in Washington, D.C.
Besides overcoming social barriers in her field, Moore focused her research on Enterobacteriaceae, a family of bacteria that includes Salmonella and E. coli. She also published a study on the relationship between gut microorganisms and antibiotics.