A. Drosophila exhibits XY type of sex determination. Males produce two types of sperms, one having X chromosome and one having Y chromosome whereas females have only X-type of chromosomes. Grasshoppers exhibit XO type of sex determination. Males produce two types of gametes, one with X chromosome and other with no sex chromosome. Thus, both show male heterogamety.
B. Female heterogamety can be seen in female birds. In these, the females have one Z and one W chromosome whereas males have a pair of Z chromosomes besides the autosomes.
