gonad, indifferent

gonad, indifferent A gonad in an embryo that has not differentiated into a definitive testis or ovary. An indifferent gonad becomes a testis if the embryo has a Y chromosome, but if the embryo has no Y chromosome, the indifferent gonad becomes an ovary. The absence of a Y chromosome permits the indifferent gonad to become an ovary, but both X chromosomes are needed for the ovary to function normally.