In the friut fly Drosophila melanogaster, vestigial wings and hairy body are pro

Question

In the friut fly Drosophila melanogaster, vestigial wings and hairy body are produced by two recessive genes located on different chromosomes. THe normal alleles, for long wings and hairless bodies are both dominant. Suppose a vestigial-winged, hairy male is crossed with a homozygous normal female.

a.)What phenotypes would be expected amounf the progeny, and what are the pheotype frequencies?

b.)If the F1 from the cross are permitted to mate randomly among themselves, what are the expected phenotypic frequencies in the F2?

Explanation / Answer

a) Normal 100%
b) (1) Hairy-and-Vestigial-Winged = 6.25%

                      (because the probability of 2 independent events occurring together is the product

                                         of their probabilities, and 0.25 X 0.25 = 0.0625)

    (2) Hairy (but not Vestigial-Winged) = 18.75%

                      (because the overall probability for hairy is 25%, including the 6.25% that is also

                                  vestigial-winged, and 0.25 - 0.0625 = 0.1875)

     (3) Vestigial-Winged but not Hairy = 18.75%

      (4) Normal = 50%

                      (notice that 1.00 - (2)(0.625) - (2)(0.1875) = 0.5)

Related Questions

Navigate

• Browse (All)
• Browse I
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.