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green Which of the following statements are true of biofilms? none false In nature, biofilms are remarkably homogenous. No. Naturally occurring biofilms are not homogeneous (uniform), but tend to be heterogeneous (not uniform). true Biofilms usually contain many different kinds of organisms. Yes. There are nearly always a large number of different kinds of microorganisms living together in a biofilm. false Biofilms tend to exhibit similar internal structures. No. Different biofilms tend to exhibit different internal structures. false Biofilms exhibit similar chemical properties. No. Different biofilms tend to exhibit different properties for most measurements and observations that researchers make. false Biofilms exhibit similar electrical properties. No. Different biofilms tend to exhibit different properties for most measurements and observations that researchers make. Some common attributes shared by biofilms include . . . none true are viscoelastic Yes. Biofilms appear to show aspects of both solids and liquids (viscoelastic). false are pathogenic No. Some, but not all, biofilms are pathogenic (disease causing). true tend to attach to surfaces Yes. Biofilms tend to share a common manner of attaching themselves to surfaces. true make it harder to destroy harmful microorganisms Yes. Individual microorganisms that are not part of a biofilm are easier to kill with the appropriate chemicals than microorganisms that are part of biofilms. false are stationary No. Biofilms are capable of movement. Which of the following statements are true of biofilm communication? none false communication is enhanced by viscoelasticity No. Viscoelasticiy refers to the ability to exhibit properties of both solids and liquids. false communication is inhibited by the biofilm matrix substance (EPS) No. In biofilms, the matrix material (EPS) that holds cells close together allows concentrations of cell-produced, chemical signal-molecules to build up in sufficient quantities for communication. true communication can set up a sort of division of labor Yes. Cell signaling can cause cells of the same bacterium variety to form subpopulations that carry out different activities (see the example of Pseudoalteromonas cited in this section of the hypertextbook). true communication can take place by quorum sensing Yes. An example of quorum sensing is that some disease-causing bacteria will not produce toxins until they sense that they have established an adequate population to survive host defenses. false microorganisms are too simple to communicate No. Cells in biofilms can coordinate behavior using biochemical signaling molecules. Which of the following statements are true of microorganism susceptibility to antimicrobial agents (chemicals designed to kill microorganisms)? none true Planktonic microorganisms tend to be more easily destroyed by antimicrobial agents than the same microorganisms in a biofilm. Yes. The illustration at the end of this section shows how biofilms can help microorganisms better survive attacks by antimicrobial agents compared to microorganisms in a planktonic state. false Microorganisms in a biofilm tend to be more easily destroyed by antimicrobial agents than the same microorganisms in a planktonic form. No. The illustration at the end of this section shows how biofilms can help microorganisms better survive attacks by antimicrobial agents compared to microorganisms in a planktonic state. false Antimicrobial agents tend to have about the same effectiveness in destroying planktonic microorganisms as they do in destroying microorganisms in a biofilm. No. The illustration at the end of this section shows how biofilms can help microorganisms better survive attacks by antimicrobial agents compared to microorganisms in a planktonic state. false Persister cells in biofilms revert to a susceptible state more readily than persister cells in a planktonic form. No. Persister cells in a planktonic form tend to revert to a susceptible state more readily than persister cells in biofilms. true Microorganisms in biofilms can better apply neutralizing power to fight off antimicrobial substances than microorganisms in a planktonic state. Yes. The collective power of groups of cells tends to lead to slow or incomplete penetration of antimicrobial agents into a biofilm.