Updated by: Arabinda Naik
In Drosophila 8 numbers of chromosomes are present. Among which 6 autosomes and 2 sex chromosomes. So, the male has three pairs of autosomes and XY chromosomes 6+XY and the female have three pairs of autosomes and XX chromosomes 6+XX. The male is heterogametic and produce two types of sperm 3+X And 3+Y and the female are homogametic, and all ova contain one type of ova 3+X and 3+X. It is found that male or female daughter formation chance is always 50%. The ovum fertilised by the X carrying sperm develops into a female while ovum fertilised by the Y carrying sperm develops into a male.