A grey male fly was crossed with a black female fly all the offspring had grey bodies what were the genotypes of the parents and the offspring
Answers
According to the question, parents are gray, short-winged fly and a black, long-winged fly. Since gray body color is dominant over black and long wings are dominant over short, the parents are homozygous for these recessive traits. The genotype of a parent with gray, short-wing is Ggll and that of black, the long-winged fly is ggLl. The ratio of black and gray progeny is 1:1 (25 percent gray, long wing and 25 percent gray, short wing: 25 percent black, short wing; and 25 percent black, long wing). Likewise, the ratio of progeny with short and long wings is also 1:1. A cross between heterozygous dominant and homozygous recessive gives 1 dominant: 1 recessive progeny. This means the parent fly with gray, short-wings is heterozygous for the body color and the parent fly with black, long-wings is heterozygous for wing length. Therefore, the genotype of the parent with gray, short-wing is Ggll and that of black, the long-winged fly is ggLl. Thus, the correct answer is option B.