Question

For the above cross, the Phenotype of the offspring would be?

Red Eyed 100%

Red Eyed 75%

Red Eyed 50%

Red Eyed 25%

Red Eyed 0%

White Eyed 100%

White Eyed 75%

White Eyed 50%

White Eyed 25%

White Eyed 0%

Answer 1

The phenotype of the offspring would be 75% red-eyed and 25% white-eyed.

This is largely based on the assumption that the allele R codes for red eye and is dominant over the allele r, which codes for white eye. This means allele r is recessive and can only be expressed in homozygous conditions.

Thus, from the genotypes of the offspring from the cross, 3 offspring have the genotype Rr, a re-eye phenotype, while 1 offspring has rr genotype, a white-eye phenotype.

In other words, the phenotypic ratio from the cross is 3:1 red-eyed offspring to white-eyed offspring.

This is also equivalent to 75%:25%.