Drosophila (fruit flies) usually have long wings (+ is the symbol used to represent this allele), but mutations in two different genes can result in bent wings ( b t ) or vestigial wings (vg). The bent and vestigial wing alleles segregate independently. In symbolizing fruit fly alleles, it is common to use two letters as opposed to only one. If flies that have long wings and are heterozygous for both the bent wing gene and the vestigial wing gene are mated, what is the probability of offspring with bent wings only?.