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Bio 411 Test 2 Questions with Answers (100% Correct
Answers)
obligate aerobes Answer: require oxygen
Mycobacterium tuberculosis Answer: example of obligate aerobe
facultative anaerobes Answer: grow via fermentation or anaerobic
respiration when oxygen is not available
E Coli Answer: example of facultative anaerobes
obligate anaerobes Answer: unable to use oxygen and are harmed by it
clostridium Answer: example of obligate anaerobes
aerotolerant anaerobes Answer: tolerate but cannot use oxygen
streptococcus mutans Answer: example of aerotolerant anaerobes
microaerophiles Answer: require oxygen concentration lower than air.
Need 1-10%
21% Answer: the percent of oxygen in the atmosphere
campylobacter spp Answer: example of microaerophiles
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Agar Answer: -Complex polysaccharide
-Used as solidifying agent for culture media in Petri plates, slants, and
deeps
-Generally not metabolized by microbes
-Liquefies at 100°C
-Solidifies at ~40°C
culture medium Answer: nutrients prepared for microbial growth
chemically defined media Answer: exact chemical composition is known
Complex Media/All purpose Answer: have nutrients (extracts, digests of
yeasts, meats, or plants). Chemical composition varies batch to batch
Nutrient broth
Nutrient Agar
Tryptic soy broth (TSB)
Reducing media Answer: used for the cultivation of anaerobic bacteria
contains sodium thioglycolate
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sodium thioglycate Answer: •reacts with all oxygen and removes
oxygen from media
•Added with heat, removes oxygen from media
Capnophiles Answer: microbes that require high CO2 conditions
ex: campylobacter
Selective media Answer: -suppress unwanted microbes and encourage
desired microbes
-contain inhibitors to suppress growth
Eosin methylene blue (EMB) Answer: contains dyes (methylene blue)
that are
toxic for Gram positive bacteria. The selective medium for gram
negative bacteria and the differential medium for lactose fermenting
bacteria
-E Coli has green metallic sheen
methylene blue Answer: blue in the presence of oxygen but is colorless
in an anaerobic environment
© 2025 All rights reserved
Bio 411 Test 2 Questions with Answers (100% Correct
Answers)
obligate aerobes Answer: require oxygen
Mycobacterium tuberculosis Answer: example of obligate aerobe
facultative anaerobes Answer: grow via fermentation or anaerobic
respiration when oxygen is not available
E Coli Answer: example of facultative anaerobes
obligate anaerobes Answer: unable to use oxygen and are harmed by it
clostridium Answer: example of obligate anaerobes
aerotolerant anaerobes Answer: tolerate but cannot use oxygen
streptococcus mutans Answer: example of aerotolerant anaerobes
microaerophiles Answer: require oxygen concentration lower than air.
Need 1-10%
21% Answer: the percent of oxygen in the atmosphere
campylobacter spp Answer: example of microaerophiles
© 2025 All rights reserved
,2
Agar Answer: -Complex polysaccharide
-Used as solidifying agent for culture media in Petri plates, slants, and
deeps
-Generally not metabolized by microbes
-Liquefies at 100°C
-Solidifies at ~40°C
culture medium Answer: nutrients prepared for microbial growth
chemically defined media Answer: exact chemical composition is known
Complex Media/All purpose Answer: have nutrients (extracts, digests of
yeasts, meats, or plants). Chemical composition varies batch to batch
Nutrient broth
Nutrient Agar
Tryptic soy broth (TSB)
Reducing media Answer: used for the cultivation of anaerobic bacteria
contains sodium thioglycolate
© 2025 All rights reserved
, 3
sodium thioglycate Answer: •reacts with all oxygen and removes
oxygen from media
•Added with heat, removes oxygen from media
Capnophiles Answer: microbes that require high CO2 conditions
ex: campylobacter
Selective media Answer: -suppress unwanted microbes and encourage
desired microbes
-contain inhibitors to suppress growth
Eosin methylene blue (EMB) Answer: contains dyes (methylene blue)
that are
toxic for Gram positive bacteria. The selective medium for gram
negative bacteria and the differential medium for lactose fermenting
bacteria
-E Coli has green metallic sheen
methylene blue Answer: blue in the presence of oxygen but is colorless
in an anaerobic environment
© 2025 All rights reserved
