Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Unit 6
MICRO EXAM 2
| Question | Answer |
|---|---|
| What temperature is most commonly used in autoclaves to sterilize growth media and other devices prior to experimentation? | 121°C |
| Which method would be LEAST effective at sterilizing a glass hockey stick to use in the spread-plate method? | pasteurization |
| Knowledge of microbial growth patterns is useful in working with the control of microbial growth. | True |
| The thermal death time is the time needed to kill all the bacteria in a particular culture at a certain temperature. | True |
| During production of a drug, all work area surfaces must be disinfected using sterilized disinfectants. Which of the following statements about disinfectants are true? | Disinfectants are used to inhibit or destroy pathogens. Endospores and viruses can resist disinfectant treatment. Disinfection can occur by physical or chemical means |
| Heat sterilization can occur in two forms: moist or dry. Autoclaving is the most commonly used application of moist heat for sterilization. Which of the following statements about autoclaving is true? | The effectiveness of an autoclave is dependent on an increase in pressure and corresponding increase in temperature. |
| Imagine that you are using a filter to sterilize a drug solution. You use a filter with a 0.22 μm pore size. Which of the following microbes will effectively be removed by this filter? | yeast bacteria such as E. coli fungi |
| Your laboratory supervisor has given you a plastic petri dish filled with soil to sterilize using radiation. What type of radiation will you use? | ionizing radiation |
| A microbiologist wants to study the virus particles from a urine sample, but not any bacteria that might be present. How can the bacteria be eliminated without harming the viruses? | Filter the sample with a 0.2 ïm pore filter |
| Most microorganisms are particularly susceptible to antimicrobial agents during the logarithmic growth phase. | True |
| What does the minimum inhibitory concentration (MIC) of a chemical tell you? | It tells you the lowest concentration of the chemical that is needed to inhibit the growth of a specific microorganism. |
| The use of chemical agents directly on exposed body surfaces to destroy or inhibit vegetative pathogens is | antisepsis |
| A chemical that denatures proteins is most likely to be classified as a(n) ________ agent. | bacteriocidal |
| What is meant by selective toxicity? | Chemotherapeutic agents should act against the pathogen and not the host. |
| Why are chemotherapeutic agents that work on the peptidoglycan cell wall of bacteria a good choice of drug? | Humans and other animal hosts lack peptidoglycan cell walls. |
| Why is polymyxin only used on the skin? | It can also damage living human cell membranes, but the drug is safely used on the skin, where the outer layers of cells are dead. |
| Quinolones and fluoroquinolones act against what bacterial target? | DNA gyrase |
| Why is it difficult to find good chemotherapeutic agents against viruses? | Viruses depend on the host cell's machinery, so it is hard to find a viral target that would leave the host cell unaffected. |
| What is meant when a bacterium is said to become "resistant" to an antibiotic? | The bacterium is neither killed nor inhibited by the antibiotic. |
| When a patient is treated with antibiotics, __________. | the drug will kill or inhibit the growth of all of the sensitive bacterial cells |
| The process of acquiring antibiotic resistance by means of bacteriophage activity is called | transduction |
| Which of the following mutations would not result in antibiotic resistance? | Silent mutation |
| R-plasmids are most likely acquired via | bacterial conjugation |
| Which antibiotic is overcome by beta-lactamases? | Penicillin |
| How might efflux pumps increase antibiotic resistance in bacteria? | Resistant bacteria can have more efflux pumps, and can have less specific efflux pumps. |
| Bacteria that are resistant to sulfonamide have enzymes that have a greater affinity for what? | PABA |
| Why would an efflux pump for penicillin located on a bacterial cell membrane not be effective at providing resistance to the drug? | Penicillin disrupts the cell wall, which is located outside of the cell membrane. |
| Membrane transport proteins are required for which mode(s) of antibiotic resistance? | Efflux pumps, beta-lactamases, and modification of porins all utilize membrane transport proteins. |
| Penicillin and other β-lactam antibiotics inhibit cell-wall synthesis. What makes them effective at killing bacterial cells? | Bacteria are generally hypertonic relative to their environment, so they burst when their cell wall is weakened by the action of these antibiotics. |
| When treating a fungal infection, the best target for selective toxicity would be __________. | ergosterol synthesis |
| Which of the following would be useful for treating Candida? | an azole |
| Most drug-resistant bacteria isolated from patients contain a(n) | R plasmid |
| Widespread antimicrobial drug resistance is usually passed by | horizontal gene transfer. |
| Antibiotic resistance is a major concern as microbes can rapidly develop resistance when antibiotics are not used appropriately. Which of the following examples best describes how this occurs? | In any population of microbes, some individuals may have resistance genes. When exposed to an antibiotic, there is selection for the microbes that have these genes. |
| Among the recommendations from the Centers for Disease Control and Prevention to limit the development of antibiotic resistance are __________. | to treat with the oldest, effective antimicrobial |
Created by:
user-1993459