suppose that three loci, each with two alleles (a and a, b and b, c and c), determine the differences in height between two homozygous strains of a plant. these genes are additive and equal in their effects on plant height. one strain (aa bb cc) is 10 cm in height. the other strain (aa bb cc) is 22 cm in height. the two strains are crossed, and the resulting f1 are interbred to produce f2 progeny. match the f2 phenotypes and expected proportions of progeny Phenotype (Height) Proportion of F2 10 cm 12 cm 14 cm 16 cm 18 cm 20 cm 22 cm 12/64 15/64 20/64 36/64 1/64 6/64