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Exam 2
Microbiology
Question | Answer |
---|---|
These are prokaryotes that grow in severe conditions: | extremophiles |
Prokaryotic cells divide by _________ ________: | binary fission |
What type of growth involves population doubling during each division? | exponential growth |
This is the time it takes for population to double: | generation time |
What environmental conditions influence generation time? | nutrients and temperature |
Generation time depends on: | bacterial species (genetics) and its growth conditions |
These are polysaccharide-encased communities: | biofilms |
This system results in nutrients not being renewed and waste not being removed | closed systems |
This system is required to maintain growth and nutrients are added but wastes are removed continuously: | open systems |
Lag phase, exponential (log) phase, stationary phase, and death phase are all: | stages of a population growth curve |
During this phase the number of cells do not increase and begin synthesizing enzymes required for growth: | Lag phase |
During this phase cells divide at a constant rate and are most sensitive to antibiotics (endospore formation begins) | Exponential (log) phase |
During this stage nutrient levels are now too low to sustain log growth and total number of bacteria in the population remain constant so for every cell that divides, two cells die: | Stationary phase |
During this stage the total number of viable cells decrease and die at a constant rate: | Death phase |
Which bacteria have this temp range: 5-15 degrees Celsius? | Pyschrophile |
Which bacteria have this temp range: 25-30 degrees Celsius? | Psychrotroph |
Which bacteria have this temp range: 25-45 degrees Celsius? | Mesophile |
Which bacteria have this temp range: 45-70 degrees Celsius? | Thermophiles |
Which bacteria have this temp range: 70-122 degrees Celsius? | Hyperthermophiles |
These are found in Arctic and Antarctic regions: | Psychrophile |
These are important in food spoilage: | Psychrotroph |
These are common in hot springs: | Thermophiles |
These are usually members of Archaea found in hydrothermal vents, volcanoes | Hyperthermophiles |
These undergo aerobic respiration and require oxygen as the terminal electron acceptor in ETS | aerobes |
These do not use aerobic metabolism; toxic forms of oxygen are harmful to these bacteria: | anaerobes |
These can maintain life via fermentation, anaerobic respiration, or by aerobic respiration: | Facultative anaerobes |
These do not use aerobic metabolism but have enzymes that detoxify oxygen's poisonous forms: | aerotolerant anaerobes |
These are aerobes that require oxygen levels from 2 to 10%, use aerobic respiration, and have a limited ability to detoxify hydrogen peroxide and superoxide radicals: | Microaerophiles |
This grows only when O2 is available: | obligate aerobe |
This grows best when O2 is available, but also grows without it: | facultative anaerobe |
This cannot grow when O2 is present: | obligate anaerobe |
This grows only if small amounts of O, are available: | microaerophile |
This grows equally well with or without O | aerotolerant anaerobe |
______________ grow optimally at pH below 5.5: | Acidophiles |
______________ grow optimally at pH above 8.5: | Alkaliphiles |
These withstand up to 10% NaCl: | Halotolerant |
These require high salt concentrations up to 9%: | Halophiles |
These require 9-30% salt concentrations: | extreme halophiles |
____________ use organic carbon: | heterotrophs |
_____________ use inorganic carbon as CO2 (carbon fixation) | autotrophs |
______________ bacteria have complicated nutritional requirements: | fastidious |
These obtain energy from sunlight; carbon from CO2: | photoautotrophs |
These obtain energy from sunlight; carbon from organic compounds: | photoheterotrophs |
These obtain energy from inorganic compounds; carbon from CO2: | chemolithoautotrophs |
These obtain energy and carbon from organic compounds: | chemoorganoheterotrophs |
These are aerobic bacteria that require increased CO2: | capnophiles |
These can incubate in gas-tight container with a chemical packet: | microaerophilic |