Let Cy = curly wings and Cy+ = wild type. In Drosophila, the Cy allele behaves as a dominant mutation that produces curly wings in the heterozygous condition (Cy/Cy+), but also behaves as a recessive lethal mutation. Flies homozygous for the Cy allele die before reaching adulthood. If you crossed flies heterozygous for the Cy allele, what phenotypes would you find in the adult F1 generation?