Question

A researcher is studying linkage between singed bristles and vestigial wings, and conducted crosses between two different strains of fruit flies. When true-breeding flies with singed bristles (s) and normal wings (L) were crossed to true-breeding flies with normal bristles (S) and vestigial wings (l), all F1 offspring had normal wings and normal bristles. The F1 offspring were crossed to flies with singed bristles and vestigial wings. Which F2 offspring is/are recombinant?A.Singed bristles/vestigial wings onlyB.Singed bristles/normal wings onlyC.Singed bristles/normal wings and normal bristles/vestigial wingsD.Singed bristles/vestigial wings and normal bristles/normal wings

Answer 1

Answer:

D.Singed bristles/vestigial wings and normal bristles/normal wings

Explanation:

Parent 1: singed bristles and normal wings ( ssLL )

Parent 2: normal bristles and vestigial wings (SSll)

ssLL X SSll =

F1: SsLl ( normal wings and normal bristles )

SsLl X ssll =

F2:

Sl/sl = normal bristles and vestigial wings = Parental

sL/sl = singed bristles and normal wings = Parental

SL/sl = normal bristles and normal wings = Recombinant

sl/sl = singed bristles and vestigial wings = Recombinant

since, singed bristles/ vesitigal wings and normal bristles/normal wings are different from parental combinations, they are the recombinant offspring.