Question

In 1910, Morgan did a series of experiments with the fruit fly Drosophila, an organism where females are XX and males are XY. When a mutant male fly with white eyes was crossed with a wild-type female with red eyes, none of the F1 progeny had white eyes but 18% of the F2 flies had white eyes. Unexpectedly, all of these white-eyed F2 flies were males. From these results, Morgan concluded that the white eye trait is caused by a recessive allele located on the X chromosome. Instead of fruit flies, suppose Morgan had done his experiments with grasshoppers, where females are XX and males are XO. In this case, if a male with a recessive X-linked trait was crossed with a wild-type female, what would you expect among the F2 progeny?

Answer 1

All the F2 progeny with recessive traits would be males

Explanation: This is because the x-linked trait chromosomes are recessive, The F1 when crossed would contain females but when crossed again the F2 progeny with recessive traits would be males