Examine molecular, cellular, organismal, ecological, and evolutionary biology of bacteria. Focus on a large number of bacteria, both Gram-positive and Gram-negative from four major phyla, that live and survive both as free-living microbes, in groups, and in both beneficial and pathogenic associations with eukaryotic hosts. Explore evolution of organelles and behaviors, including receiving and transducing signals that produce a variety of outcomes such as chemotaxis and motility, morphogenesis and development, secretion and virulence, quorum sensing and biofilms, bacterial warfare, and antibiotic production and tolerance. Three lecture hours a week for one semester. Biology 339M and Molecular Biosciences 339M may not both be counted. Prerequisite: Biology 325 or 325H with a grade of at least C-, and Molecular Biosciences 326R (or Biology 326R) with a grade of at least C-.