Embryos are gonadally identical, regardless of genetic sex, until a certain point in development; when the testis-determining factor causes male sex organs to develop, whereas lack of this factor will cause the embryo to develop as physically female.
Embryos are gonadally identical until a certain point in development;. This is regardless of genetic sex. The testis-determining factor causes male sex organs to develop. Lack of this factor will cause the embryo to develop as physically female.