Through questioning science Anne Fausto-Sterling came up with alternatives to the concept of having only two sexes, male and female. She argues that through biological development there is a possibility of having five sexes instead of two. She believes there are male, female, merm (male pseudohermaphrodites, i.e. when testicular tissue is present), ferm (female pseudohermaphrodites, i.e. when ovarian tissue is present), and herm (true hermaphrodites, i.e. when both testicular and ovarian tissue is present).
