In the life cycle of Drosophila meiosis takes place in the adult stage in ovaries and testes of adult Drosophila. It occurs before the fertilization of the eggs.
Sex is determined by X and Y chromosomes. Males and females are easily distinguished.
In salivary glands and certain other tissues, multiple rounds of DNA replication without chromosomal division result in giant chromosomes.
After meiosis, fertilization occurs and the eggs are laid by the female. This is the stage 1in the life cycle of Drosophila.