Too funny, actually there is a Z chromosome used in sex determination (W & Z are counterparts to X & Y in birds). Also, sex is not determined strictly by genes

Too funny, actually there is a Z chromosome used in sex determination (W & Z are counterparts to X & Y in birds). Also, sex is not determined strictly by genes it's determined by gamete size. And yes there are two sexes and gender is not binary, but it is by bimodal with significant overlap. https://open.lib.umn.edu/evolutionbiology/chapter/7-4-sex-its-about-the-gametes-2/ https://open.lib.umn.edu/evolutionbiology/chapter/7-4-sex-it...