sunflowers with flowers 12 cm in diameter are crossed with sunflowers with 24 cm flowers. the f1 plants have flowers that are 18 cm in diameter. in the f2 generation, 4 flowers are 12 cm in diameter, 4 are 24 cm in diameter, and there are 5 phenotypic classes with diameters intermediate to the extremes. assuming that the alleles that contribute to flower diameter act additively, how many genes control flower size in this strain of sunflowers? how much does each additive allele contribute to flower diameter? if there are 256 flowers, how many would you expect in each size class?
