The genetic process in which the sex of an organism is determined is called sex determination. Miss N. M. Stevell and Wilson proposed the theory of sex determination in insects after extensive research. According to this doctrine, the method of gender determination is sterile.
- XX-XY System: According to this system female is homogametic or XX and male is heterogametic or XY. Females produce one type of egg (X) and males produce two types of sperm (X and Y). When a woman’s egg X meets a man’s sperm X, a female child (XX) will be produced. Again, the union of the woman’s egg X with the man’s sperm Y will produce a son (XY). This method determines the sex of animals such as humans, Drosophila, various insects, cannabis, cockroaches, Elodea etc.
- XX-X0 System: According to this system female is homogametic or XX and male has X chromosome and not Y. Females produce the same type of egg (X) and males produce two types of sperm (X and A). When a woman’s egg X meets a man’s sperm X, a female child (XX) will be produced. Again, the union of the woman’s egg X with the man’s sperm A will produce a son (XA). This method determines the sex of animals like grasshoppers, beetles, Orthoptera, Heteroptera, Dioscorea (plants).