Final answer:
The ZZ-ZW sex determination system results in a male if the sex chromosomes are homozygous ZZ, and a female if heterozygous ZW. This is unlike the mammalian system where XX denotes females and XY denotes males.
Step-by-step explanation:
In the ZZ-ZW sex determination system, a eukaryotic diploid cell from an organism with two pairs of autosomes and a pair of sex chromosomes, consisting of Z and W, will determine the sex of the individual. If the sex chromosomes are homozygous for Z (ZZ), the result is a male. Alternatively, if the configuration is heterozygous with ZW, it results in a female.
This system is utilized by various species including birds, some fish, crustaceans, insects such as butterflies and moths, and reptiles. Unlike in mammals, where females are XX and males are XY, in the ZZ-ZW system, females have different sex chromosomes (ZW), which is the heterogeneous pair. The W chromosome is crucial for female sex determination, akin to the role of the Y chromosome in mammals.