Q. True breeding Drosophila flies with curved wings and dark bodies were mated with true breeding short wings and tan body Drosophila, The F1 progeny was observed to be with curved wings and tan body. The F1 progeny was again allowed to breed and produced flies of the following phenotype, 45 curved wings tan body, 15 short wings tan body, 16 curved wings dark body and, 6 short wings dark body. The mode of inheritance is