Genes-
The important relationship between DNA and the characteristics of an organism was derived from studies of both fungi (Neurospora crassa) and bacteria (Pneumococcus, E. coli). The main finding that genes act by controlling the specificity of protein synthesis was obtained from work with mutants of the fungus Neurospora crassa that led to propose that 1 gene = 1 enzyme
Bacteria, particularly E. coli have been used to define this relationship more precisely. Thus:1 gene (or cistron) = 1 polypeptide
