In 1910,Morgan Did a Series of Experiments with the Fruit

question 57

Multiple Choice

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 progeny had white eyes.Unexpectedly,all of these white-eyed F₂ flies were males.Based on these results,Morgan concluded that white eyes is caused by a recessive X-linked allele.Suppose Morgan had found that half of the F1 progeny had white eyes but all of these white-eyed F₁ flies were females.In this case,a valid hypothesis would be

• A)White eyes is caused by a recessive Y-linked allele.
• B)White eyes is caused by a dominant Y-linked allele.
• C)White eyes is caused by a dominant X-linked allele.
• D)White eyes is caused by a dominant autosomal allele.