Sex chromosomes SEX DETERMINING SIGNAL MALE FEMALE Fruitfly XY XX of X: s Mammals XY XX Y(+or) Nematodes x0ⅩX of X: s hermaphrodite Birds ZZ ZW Some reptiles temperatureFruitfly XY XX # of X’;s Sex chromosomes SEX DETERMINING SIGNAL MALE FEMALE Mammals XY XX Y (+ or -) Nematodes XO XX # of X’;s hermaphrodite Birds ZZ ZW ? Some Reptiles temperature