CCRI micro exam 2 vito Questions And Answers With Verified Study Quiz

Chlorine and iodine are classified as - halogens Obligate aerobes can only live - when oxygen is present Microorganism found thriving in a the permafrost region of the Arctic are - pychrophiles Facultative halophiles - tolerate an elevated salt concentration in the environment Most bacteria prefer to grow at which pH range? - Most bacteria prefer to grow at which pH range? The spectrophotometer is used in microbiology to - indirectly measure microbial growth Pyrimidine dimers are formed in DNA when DNA - absorbs UV radiation These microorganisms are anaerobic but can live in the presence of oxygen even though they do not actually use the oxygen - aerotolerant Which statement is true concerning penicillin? - it destroys the cell wall of bacteria by breaking down peptidoglycan A type of antibiotic that injures the plasma membranes is - polymyxin B This type of bacteria is most likely to spoil refrigerated food - psychrotrophs Cultures of a bacterial species were incubated on the shelf of a refrigerator, out on a lab bench top, on the shelf of a 37° C incubator and on the shelf of a 50° C incubator. After incubation, there was nogrowth at 37° C and 50° C, slight growth out on the bench top, and abundant growth at refrigeration. What term could be used for this species? - psychrotroph Most human diseases are caused these microorganisms - mesophiles A microorganism that does not have the enzymes catalase or superoxide dismutase would find it difficult to live in an environment with - oxygen Which antibiotic binds to the 50s portion of the ribosome and inhibits the formation of the peptide bond? - chloramphenicol Microorganisms living around deep sea hydrothermal vents are classified as - hyperthermophiles Sulfanilamides inhibit - enzyme function Mesophiles grow best - body temperature Fungi are not affected by penicillin because they lack - peptidoglycan in their cell walls Competitive inhibitors stop enzyme action by binding to - the active site of the enzyme Microorganisms that can live in the Dead Sea are classified as - extreme halophiles When bacteria are placed in a hypotonic solution, what physiological process occurs? - osmotic lysis Microorganisms that live in hot springs are - hyperthermophiles Microorganisms that use oxygen in lesser amounts than obligate aerobes are - microaerophilesIf the bacterial membrane is destroyed by an antibiotic, which of the below would be responsible? - polymixin B If 1 mL of bacteria from an original culture is transferred from a stock culture to 9 mL of sterile broth, then 1mL of the broth culture is transferred to 9 mL of a second broth culture, how much has the original culture been diluted? - 1:100