Question

A researcher makes a promoter construct in flies that expresses Gal4 in all of the legs, and by chance, it is on the X-chromosome. She breeds a male of this new Gal4 line into a line that is homozygous for a UAS: GFP (Green Flourescent Protein) line AND a heat shock Gal80 line that is expressed in all cells when the temperature is raised above 26^*C; both those constructs on autosomes. If all constructs work as expected and segregation works in a Mendelian fashion, what happens in the F1 when the temperature is shifted from 28*C to 20*C.

A. GFP will begin to be expressed in the 1st in one half of the females

B. GFP will begin to be lost in the legs of one half of the progeny

C. GFP will begin to be lost in the legs of all of the females

D. GFP will begin to be expressed in the legs of all of the females

E. GFP will begin to be expressed in the legs of one half of the males

Answer 1

GFP will begin to be expressed in the legs of all of the females.

It is because since in Drosophila females are made from ratio of autosomes and sex chromosome.

So all the constructs will be expressed since all females have autosomes and sex chromosomes.