Class 12 NEET Biology Principles of Inheritance and Variation Questions Part 1

The female Drosophila possesses two homomorphic sex chromosomes (XX) and the male Drosophila contains two heteromorphic sex chromosomes (XY). The differential or nonhomologous region of Y-chromosome is mostly heterochromatic. The female parent produces only one type of eggs (22+X). The male parent produces two types of gametes (22+Y) and (22+X). They are produced in equal proportions. As the two types of sperms are produced in equal proportions, there are equal chances of getting a male or female fly in a particular mating.