Question

Wild type fruit flies have broad, straight wings and pale-colored bodies with dark transverse stripes. Some fruit flies mutant for the wing size trait and produce nubby, vestigial wings, an allele that is recessive to the wild type allele. Ebony body color is recessive to the normal pale, striped body color. Two flies heterozygous for both traits mentioned above are mated. What proportion of their offspring will exhibit the dominant phenotype for both traits?

Answer 1

Answer:

9/16

Explanation:

Let  broad, straight wings be represented by the allele W. Homozygous condition will be WW or ww while heterozygous condition will be Ww

Let pale-colored body with dark transverse stripes is represented by C. Homozygous condition will be CC or cc while heterozygous condition will be Cc.

Heterozygous condition for both trait will be WwCc. Hence a mating between two flies that are heterozygous for both trait will be;

                               WwCc     x       WwCc

This will yield offspring in the following phenotypic ratio;

Broad, straight wings with pale-colored body/dark transverse stripes - 9/16

Broad, straight wings with ebony body colour - 3/16

Nubby, vestigial wings with pale-colored body/dark transverse stripes - 3/16

Nubby, vestigial wings with ebony body colour - 1/16.

See the attached image for the Punnet square result of the cross.

The proportion is 9/16