Balanced ory of sex determine is related to which of following?

The gene balanced theory was proposed by the Bridge. In Drosophila, Y chromosome does not use in sex determination. A single X chromosome in a diploid individual will make it male. The pair of  X chromosomes in a diploid individual make it female. Although both mammals and fruit flies produce XX females and XY males, their chromosomes achieve these ends using very different means. The sex-determining mechanisms in mammals and in insects such as Drosophila are very different. In mammals, the Y chromosome plays a pivotal role in determining the male sex.