What is the role of the X chromosome in Drosophila sex determination?
Determines the number of autosomes
Determines the sex of the individual
Promotes male development
Promotes female development
In Drosophila, the X chromosome is essential for determining sex. The sex of a person is determined by the amount of X chromosomes compared to the amount of sets of autosomes (A).
Female Drosophila have a pair of X chromosomes, while males possess a single X and a single Y chromosome. The male or female gender of an individual is determined by a ratio of X chromosomes to the numbers of autosomes (A). For example, a 1:1 ratio (one X chromosome to two sets of autosomes) results in a female fly, but a 1:2 ratio (one X chromosome to four sets of autosomes) results in a male fly.
Option 4 is the correct answer.