XY sex-determination system
Videos
The XY sex-determination system is a sex-determination system present in many mammals, some insects, some snakes, some fish, and some plants.
Pollen cones of a male Ginkgo biloba tree, a dioecious species
Ovules of a female Ginkgo biloba
PBB Protein SRY image
Nettie Stevens in 1904
ZW sex-determination system
Videos
The ZW sex-determination system is a chromosomal system that determines the sex of offspring in birds, some fish and crustaceans such as the giant river prawn, some insects, the Schistosomatidae famil
XY sex-determination system
…species with XY sex determination, an organism must have at least one X chromosome in order to survive. The XY system contrasts in several ways with the ZW sex-determination system found in birds, some insects, many reptiles, and various other animals, in which the heterogametic sex is female. A temperature-dependent sex determination…
ZW sex determination in birds (as exemplified with chickens)
Mice X Y chromosomes