Question

Wing size in Drosophila results from a pair of X-linked partially dominant alleles. L^M produces long wings and L^m produces miniature wings. When both alleles are present in the heterozygous condition, medium-sized wings are produced. A female fly with miniature wings is crossed with a male that has long wings.

a). What are the genotypes of the female and male flies described above? What are the genotypes of the gametes that each fly makes? (4 pts)

Female genotype:                                                         Female gamete(s):

Male genotype:                                                            Male gamete(s):

b). What are the genotypic and phenotypic ratios of the F₁ progeny? (6 pts)

c). Under normal circumstances, would you expect to observe male flies with medium-sized wings? Explain. (3 pts)

d). Sepia eyes are produced by an autosomal allele, s, that is recessive to an allele for red eyes, S. If the original female fly with miniature wings (part a.) has sepia eyes and the original male fly with long wings (part a.) is heterozygous for red eyes, what is the probability that they will produce a medium-winged female fly with sepia eyes? (4 pts)

e). Despite the probability you calculated in part d. for producing medium-winged, sepia females, no sepia flies were seen when 100 progeny were observed. Explain why this might be so. (3 pts)

Answer 1

Find the below image for answer

a) The genotype of Female = XLm XLm and male is XLM Y

The gametes from female is XLm and from the male is XLM and Y.