Final answer:
Two red-eyed fruit flies can produce white-eyed offspring if both parents are heterozygous for the red eye color allele (Ee). A cross between two such heterozygous individuals (Ee x Ee) can indeed result in a white-eyed offspring due to the combination of recessive alleles (ee).
Step-by-step explanation:
It is indeed possible for two red-eyed fruit flies to have white-eyed offspring, but only under specific genetic conditions. The correct crosses that could result in white-eyed offspring are: the cross Ee x Ee. For this outcome to occur, both parents must be heterozygous for the eye color gene, which means they both have one dominant (red eye color) allele and one recessive (white eye color) allele.
Let's break this down: If both red-eyed parents are heterozygous (Ee), then there is a 25% chance for the offspring to be white-eyed (ee) when we apply the Punnett square method. This can be visualized as follows:
- The father contributes an 'E' or an 'e' allele.
- The mother contributes an 'E' or an 'e' allele.
When both parents contribute an 'e' allele, the offspring will have the genotype 'ee' and will exhibit white eyes, which is a recessive trait and only expressed when there are two copies of the recessive allele.
Option a) is incorrect because the cross EE x ee will only result in red-eyed offspring. Option b) is not possible as explained above; with heterozygous parents, there is a chance for white-eyed offspring. Option d) is incorrect because it does not take into account the possibility of heterozygous red-eyed parents. Option c) is correct, as explained.