- Recombination in dihybrid crosses
You have screened for several new recessive mutations in a species of wasp.
Wasps homozygous for apricot (aa) have pale orange eyes. (Wild-type eyes are brown.)
Wasps homozygous for blunt (bb) have short wings. (Wild-type wings are long.)
You make a pure-breeding double-mutant (apricot, blunt
) line and cross it with wild-type wasps. The F1
is wild-type in appearance.
You testcross the F1
dihybrids with the double-mutant line (the “tester” genotype) and obtain four phenotypes in the F2
Determine the following for each F2
the haploid genotype of the gamete it received from the F1 dihybrid
its full diploid genotype
whether the gamete it received from the F1 dihybrid was recombinant (REC) or nonrecombinant (nonREC).