14. Dr. Disney has been raising exotic fruit flies for decades. Recently, he dis

Question

14. Dr. Disney has been raising exotic fruit flies for decades. Recently, he discovered a strain of fruit flies that in the recessive condition have baby blue eyes that he designates as bb. He also has another strain of fruit flies that in the recessive condition have pink wings that are designated as pw. He is able to establish flies that are homozygous for both mutant traits. He mates these two strains with each other. Dr. Disney then takes phenotypically wild-type females from this cross and mates them with double recessive males. In the resulting testcross progeny, he observes 500 flies that are of the following make-up: 41 with baby blue eyes and pink wings 207 with baby blue eyes only 210 with pink wings only 42 with wild-type phenotype Assuming the wild-type alleles for these two genes are b+ and pw+, what is the correct testcross of the F1 flies?

a. b+ pw+/b pw b pw/b pw

b. b+ pw+/b pw b pw+/b+ pw

c. b+ pw/b pw+ b pw/b pw

d. b+ pw/b pw+ b+ pw+/b pw

e. b+ pw+/b pw b+ pw/b pw+

( I know the answer but i dont know why)

Explanation / Answer

Recessive Traits: baby blue eyes (bb); pink wings (pw)

Test cross involves the Crossing of Either homozygous or Heterozygous dominant flies with Homozygous recessive flies. Answer is A & C. The Condition A showing Cis arrangement of the Dominant alleles and Condition C showing the Trans arrangement of the dominant alleles

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

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