The phenotype is the physical manifestation of the genotype and the polypeptides it codes for—for example, the rose. The color and shape of the petals (the phenotype) are the result of chemical reactions within the cells of each petal. Polypeptides synthesized from the directions encoded within the cell’s genes (the genotype) are part of those reactions. Different versions of a gene will produce different polypeptides, which in turn will cause different molecular interactions and ultimately a different phenotype.