Researchers studying the rigidity and fexibility of the cell envelope used chemotaxis to measure the ability of microbes to squeeze through tight spaces. E. coli, a gram-negative bacterium, was able to traverse narrower channels than B. subtilis, a gram-positive microbe, even though both cells are the same size when grown without restriction. E. coli has the more fexible cell envelope because _______.
A) it has fewer flagella B) there are fewer protein receptors C) it has only a single membrane D) lipopolysaccharide has no charge E) there is less structural carbohydrate
A clinical laboratory that identifies the bacterial agents that cause human disease would refer to Bergey's Manual of ______ Bacteriology for guidance in identification.
A) Evolutionary B) Classical C) Systematic D) Determinative
Archaea have been found in many microenvironments in the human body. Which of the following microenvironments is most likely to fit with the designation of Archaea as "extremophiles?"
A) The gingiva and the gut are anaerobic. B) The inner ear can withstand increased pressure. C) The temperature of the testes is less than 37°C. D) The surface of the tongue has salt receptors.