I'm going to be brief and not explain mechanisms, because I need to get back to gossipy sensationalism, but this should give you an idea of the diversity:
Fruit flies: ratio of X chromosomes to autosomes. "Whenever the ratio of X’s to A’s was 1.0 or greater, the fly was female, and whenever it was 0.5 or less, the fly was male. Flies with an X:A ratio between 0.5 and 1.0 developed characteristics of both sexes."
Birds, butterflies, and some reptiles: as zdenka describes.
Honeybees: diploid embryos develop from fertilized eggs and become female; haploid embryos develop from unfertilized eggs and become male.
Wasps: similar, but you can get sterile diploid males.
Some fish: females XY, males YY.
Some reptiles: it depends not on chromosomes but on the temperature at which the egg was kept.
Clown fish: start out as male. The largest and most dominant male becomes female when its reproducing time. (That's right: Marlin wants to find Nemo so Marlin can have a sex change and Nemo can fertilize his [her] eggs.)
Okay, away from giant ants and back to (post-)Fritzmas!
no subject
Fruit flies: ratio of X chromosomes to autosomes. "Whenever the ratio of X’s to A’s was 1.0 or greater, the fly was female, and whenever it was 0.5 or less, the fly was male. Flies with an X:A ratio between 0.5 and 1.0 developed characteristics of both sexes."
Birds, butterflies, and some reptiles: as zdenka describes.
Honeybees: diploid embryos develop from fertilized eggs and become female; haploid embryos develop from unfertilized eggs and become male.
Wasps: similar, but you can get sterile diploid males.
Some fish: females XY, males YY.
Some reptiles: it depends not on chromosomes but on the temperature at which the egg was kept.
Clown fish: start out as male. The largest and most dominant male becomes female when its reproducing time. (That's right: Marlin wants to find Nemo so Marlin can have a sex change and Nemo can fertilize his [her] eggs.)
Okay, away from giant ants and back to (post-)Fritzmas!