Question

You cross a true breeding wild type female with a true breeding male that is homozygous for the mutations for black body color and vestigial wings. This cross produces an F1 generation that is heterozygous for both loci. You cross one of the heterozygous females with a true breeding male from the original mutant stock. The cross produces 1,728 flies with the following phenotypes: Normal body normal wings 462 flies, Black body vestigial wings 460 flies, normal body vestigial wings 396 flies, black body normal wings 410 flies. How many flies would you expect to see for each phenotype if the loci are assorting independently?

Answer 1

The predicted numbers are based on the assumption that the traits of body color and wing size in fruit flies assort independently. If the traits do assort independently, we would expect equal numbers of flies for each phenotype. However, the observed numbers deviate slightly from the expected numbers, suggesting that there may be some degree of linkage between the loci for body color and wing size.

Step-by-step explanation:

The predicted numbers are based on the assumption that the traits of body color and wing size in fruit flies are assorting independently. This means that the inheritance of one trait does not affect the inheritance of the other trait.

According to the data obtained from the cross, if the traits are assorting independently, we would expect to see equal numbers of flies for each phenotype. So, in this case, we would expect to see 432 flies for each phenotype: normal body normal wings, black body vestigial wings, normal body vestigial wings, and black body normal wings.

However, the observed numbers deviate slightly from the expected numbers, which suggests that the traits may not assort completely independently. There may be some degree of linkage between the loci for body color and wing size.