Homework Soursehow does sex determination in Drosophila differ from sex det
how does sex determination in Drosophila differ from sex determination in humans?
| a. | In Drosophila, sex determination is environmental with the sexual phenotype being determined by the temperature during embryonic development while in humans X and Y sex chromosomes determine sex. |
| b. | Drosophila uses a XX-XO system of sex determination with males having one X chromosome and females having two X chromosomes while humans use a XX-XY system of sex determination. |
| c. | In Drosophila, the presence of a Y chromosome determines the male sex and flies with one X chromosome without a Y are female while in humans the presence of two X chromosomes produces the female sex while a single X chromosome without a Y chromosome results in the male sex. |
| d. | In Drosophila, sex is determined by the X:A ratio (the number of X chromosomes divided by the number of haploid sets of autosomal chromosomes), while in humans the presence of a Y chromosome produces the male sex and the absence of a Y chromosome results in the female sex. |
| e. In Drosophila, an individual with two sets of autosomes and XXY chromosomes would be a male, while in humans such an individual would be a female. |
Solution
Option D is the correct answer.
Presence of 1:1ratio of X and autosomes confers female sex. Presencebof Y chromosome makes the fly normal male with the ability to produce sperm.absence of Y chromosome with X :A ratio of 0.5 makes it sterile male. Whereas in humans presence of Y chromosome makes normal men.
