Final answer:
In a cross between a white-eyed male fruit fly and a heterozygous red-eyed female, the progeny would have a 1:1:1:1 genotypic ratio with 50% of offspring exhibiting wild-type red eye color. This is due to X-linked inheritance where white-eyed trait is recessive and red-eye color is dominant.
Step-by-step explanation:
The question deals with X-linked inheritance in Drosophila melanogaster, commonly known as fruit flies. When considering a cross involving eye color, the white-eyed trait is recessive and is denoted as Xw while the red or wild-type eye color is dominant and denoted as XW. Males have one X chromosome and one Y chromosome (XY), making them hemizygous for X-linked traits, while females have two X chromosomes (XX).
In a cross between a white-eyed male (XwY) and a female that is heterozygous for red eye color (XWXw), the offspring's genotypes and phenotypes can be predicted using a Punnett square. The female can produce two types of gametes: XW or Xw, while the male can only produce Xw or Y. This results in the following offspring genotypes:
- XWXw - Red-eyed female (heterozygous)
- XwXw - White-eyed female (homozygous recessive)
- XWY - Red-eyed male (hemizygous)
- XwY - White-eyed male (hemizygous for the white allele)
The phenotypic ratio of offspring would be 1 red-eyed female : 1 white-eyed female : 1 red-eyed male : 1 white-eyed male. Therefore, the ratio of offspring with the wild-type or red eye color is 50% (half the females and half the males).