Suppose you are carrying out a series of crosses with an insect where the mechanism of determination is unknown. you discover a mutant female with short wings and decide to cross it with a wild-type male that has normal wings. none of the f₁ progeny have short wings but among the f₂ progeny 26% have short wings. however, all of these short-winged f₂ progeny are females. based on these results, a valid hypothesis would be . females are xx. males are xy and black wing scales are caused by n recessive allele on the x chromosome b. females are xx. males are xy and black wing scales are caused by a dominant allele on the x chromosome. c. females are zw. males are zz and black wing scales are caused by a recessive allele on the z chromosome. d. females are zw, males are 11 and black wing scales are caused by a dominant allele on the z chromosome.