简答题If one calculates the volume needed to house the essential components of a free-living cell- proteins, nucleic acids, ribosomes, and so on, cells in _______ diameter are probably the lower limit. A、 0.15-0.2 micrometer B、 0.5-1 micrometer C、 0.5-1 nanometer D、 1.5-2 micrometer简答题Regarding membrane linkages, which statement is true? A、Eukarya have ester linkages; Bacteria have ether linkages. B、Bacteria have ester linkages; Archaea have ether linkages. C、Bacteria and Eukarya have ester linkages; Archaea linkages are not yet known. D、Archaea have ester linkages; Eukarya have ether linkages.简答题Depending on the cell type, sterols can make up from ______ of the total lipids of eukaryotic membranes. A、25 to 40% B、5 to 25% C、0.5 to 2.5% D、1 to 5%简答题_______ present in the membranes of many Bacteria, they are molecules similar to sterols, and may play a role similar to that of sterols in eukaryotic cells. A、Isoprenes B、Hopanoids C、Phytanyl D、Lipoproteins简答题The structure of the lipopolysaccharide (LPS) of G- bacteria does NOT contain ________. A、O-specific polysaccharide B、Core polysaccharide C、Lipid A D、Isoprene简答题Pseudopeptidoglycan is a characteristic of the walls of A、Bacteria and Archaea B、Eukarya C、Bacteria D、Archaea简答题Which structure is involved in the genetic exchange (conjugation) between cells? A、porin B、capsule C、pilus D、fimbria简答题Which is the only group of microorganisms that contain lipopolysaccharides (LPS)? A、gram-positive bacteria B、gram-positive and gram-negative Bacteria C、Archaea D、gram-negative bacteria简答题An organism of the genus Staphylococcus will be __________, while an organism of the genus Spirochaeta will be __________. A、spherical / rod-shaped B、coiled / spherical C、spherical / coiled D、rod-shaped / coiled简答题Which structural component(s) allow(s) for motility in Escherichia coli? A、peritrichous flagella B、cilia C、pili D、polar flagella