Final answer:
When crossing a homozygous red-eyed female fruit fly with a white-eyed male fruit fly, all offspring are expected to have red eyes due to the dominant nature of the red eye allele on the X-chromosome. Males will be hemizygous with genotype XWY, while females will be heterozygous with genotype XWXw. This demonstrates an X-linked inheritance pattern in Drosophila melanogaster.
Step-by-step explanation:
In the context of inheritance patterns in fruit flies, also known as Drosophila melanogaster, which serves as an essential model organism in genetic studies, the eye color trait is X-linked. Eye color in Drosophila is determined by a gene located on the X-chromosome. The red eye color allele is dominant (represented by XW), while the white eye color allele is recessive (represented by Xw).
When crossing a homozygous red-eyed female fruit fly (genotype XWXW) with a white-eyed male (genotype XwY), we can predict the genotype of the offspring. Female fruit flies receive one X-chromosome from each parent, while male fruit flies receive the X-chromosome from their mother and the Y-chromosome from their father. Therefore, the male offspring will have genotype XWY (red eyes) and the female offspring will have genotype XWXw (red eyes, but heterozygous). Consequently, the expected outcome of such a cross would be all offspring having red eyes.
If, hypothetically, you were to cross a white-eyed male (XwY) with a heterozygous red-eyed female (XWXw), the reverse of the original question, the resulting offspring would have different genotypes and phenotypes. In this scenario, 50% of the male offspring would have red eyes (XWY) and the other 50% would have white eyes (XwY). Similarly, 50% of the female offspring would be heterozygous with red eyes (XWXw) and the remaining 50% would be homozygous recessive with white eyes (XwXw).