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MIP302 FINAL EXAM WITH CORRECT ACTUAL
QUESTIONS AND CORRECTLY WELL DEFINED
ANSWERS LATEST 2024 – 2025 ALREADY GRADED A+
thermophiles - (answers)bacteria that live in environments with elevated
temperatures (above 131°F)
super/hyper thermophile - (answers)bacteria that live in environments with
extremely elevated temperatures (above 300°F)
Differential Media - (answers)allows for growth of bacteria, but differentiates
bacteria based on some characteristic appearance on a media type
Selective media - (answers)allows for certain types of bacteria to grow (inhibits
others)
Aerobic bacteria - (answers)require atmospheric oxygen
microaerophilic bacteria - (answers)Require atmospheric oxygen but at reduced
levels
facultative anaerobes - (answers)Grow with or without oxygen (better with
oxygen)
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obligate anaerobe - (answers)grow in absense of atmospheric oxygen
Ambient air - (answers)Normal air
candle jar - (answers)reduced levels of O2, higher levels of CO2
GasPak - (answers)reduced environment (devoid of O2)
Redox indicators for Gaspak and Candle jar - (answers)Redox indicator methylene
blue (blue when oxidized, white in reduced state)
Catalase Test - (answers)To see if bacteria produces enzyme catalase; add 3%
H2O2 to a DRY smear of bacteria; produces bubbles=(+); delayed/no bubbles=(-)
Oxidase Test - (answers)To see if bacteria produces cytochrome oxidase (uses
cytochrome C and cytocrhome oxidase in ETC); uses Oxidrop as reagent;
blue/maroon=oxidized, (+); colorless= reduced, (-); 3 MIN
PR Glucose Broth - (answers)Testing for glucose fermentation; Differential media
(ability to ferment carb); phenol red indicator (yellow in acidic, red in basic);
contains peptone and beef extract in PR broth; Durham tube put in tube to catch
gas; yellow=(+); red=(-); 18-24 hours
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Nitrate Broth - (answers)Differential media [ability to reduce nitrate (NO3) to
nitrite (NO2)] using anaerobic resp.; Nitrate A and Nitrate B reagents (react w/
nitrite--> red); RESULTS: red during first round, (+) nitrate reductase, (-) nitrite
reductase; Colorless during first round, inconclusive, add zinc; Red during second
round (Nitrate A, B, and zinc) (-) for nitrate and nitrite reductase; Colorless during
second round (+) nitrate and nitrite reductase; 48 HOURS
MacConkey Agar - (answers)To test for lactose fermentation of Gram (-) rods;
differential media (lactose fermentation); selective media (grows Gram - enteric
bacilli, inhibits Gram - cocci and Gram +); neutral red reagent (red in acidic, yellow
in basic); contains peptone and beef extract; RESULTS: red/dark-pink colonies
surrounded by zone of bile salt, strong lactose fermenter; colorless colonies, do
not ferment lactose; if no growth, cannot make conclusions about lactose
fermentation; 18-24 HOURS
Phenylethyl Alcohol (PEA) Agar - (answers)Test for Gram (+) growth; Selective
(selective component 1/4 phenylethyl OH); not as stringent as MacConkey;
RESULTS: growth, most likely Gram (+) but have to do a Gram stain to check; 18-
24 HOURS
Blood Agar (BAP) - (answers)Used to cultivate medically significant bacteria; all-
purpose media; differential (ability to hemolyze red blood cells); includes TSA and
sheep red blood cells; RESULTS: BETA, complete hemolysis, clear zone
surrounding colonies; ALPHA, incomplete lysis, green-ish brown area surrounding
colony; GAMMA, no lysis; Don't look at colony itself to determine results; 24
HOURS
Pseudosel Agar (Cetrimide Agar) - (answers)Used to isolate and identify
Pseudomonas aeruginosa; Selective (P. aeruginosa can grow, all others inhibited
MIP302 FINAL EXAM WITH CORRECT ACTUAL
QUESTIONS AND CORRECTLY WELL DEFINED
ANSWERS LATEST 2024 – 2025 ALREADY GRADED A+
thermophiles - (answers)bacteria that live in environments with elevated
temperatures (above 131°F)
super/hyper thermophile - (answers)bacteria that live in environments with
extremely elevated temperatures (above 300°F)
Differential Media - (answers)allows for growth of bacteria, but differentiates
bacteria based on some characteristic appearance on a media type
Selective media - (answers)allows for certain types of bacteria to grow (inhibits
others)
Aerobic bacteria - (answers)require atmospheric oxygen
microaerophilic bacteria - (answers)Require atmospheric oxygen but at reduced
levels
facultative anaerobes - (answers)Grow with or without oxygen (better with
oxygen)
,2|Page
obligate anaerobe - (answers)grow in absense of atmospheric oxygen
Ambient air - (answers)Normal air
candle jar - (answers)reduced levels of O2, higher levels of CO2
GasPak - (answers)reduced environment (devoid of O2)
Redox indicators for Gaspak and Candle jar - (answers)Redox indicator methylene
blue (blue when oxidized, white in reduced state)
Catalase Test - (answers)To see if bacteria produces enzyme catalase; add 3%
H2O2 to a DRY smear of bacteria; produces bubbles=(+); delayed/no bubbles=(-)
Oxidase Test - (answers)To see if bacteria produces cytochrome oxidase (uses
cytochrome C and cytocrhome oxidase in ETC); uses Oxidrop as reagent;
blue/maroon=oxidized, (+); colorless= reduced, (-); 3 MIN
PR Glucose Broth - (answers)Testing for glucose fermentation; Differential media
(ability to ferment carb); phenol red indicator (yellow in acidic, red in basic);
contains peptone and beef extract in PR broth; Durham tube put in tube to catch
gas; yellow=(+); red=(-); 18-24 hours
, 3|Page
Nitrate Broth - (answers)Differential media [ability to reduce nitrate (NO3) to
nitrite (NO2)] using anaerobic resp.; Nitrate A and Nitrate B reagents (react w/
nitrite--> red); RESULTS: red during first round, (+) nitrate reductase, (-) nitrite
reductase; Colorless during first round, inconclusive, add zinc; Red during second
round (Nitrate A, B, and zinc) (-) for nitrate and nitrite reductase; Colorless during
second round (+) nitrate and nitrite reductase; 48 HOURS
MacConkey Agar - (answers)To test for lactose fermentation of Gram (-) rods;
differential media (lactose fermentation); selective media (grows Gram - enteric
bacilli, inhibits Gram - cocci and Gram +); neutral red reagent (red in acidic, yellow
in basic); contains peptone and beef extract; RESULTS: red/dark-pink colonies
surrounded by zone of bile salt, strong lactose fermenter; colorless colonies, do
not ferment lactose; if no growth, cannot make conclusions about lactose
fermentation; 18-24 HOURS
Phenylethyl Alcohol (PEA) Agar - (answers)Test for Gram (+) growth; Selective
(selective component 1/4 phenylethyl OH); not as stringent as MacConkey;
RESULTS: growth, most likely Gram (+) but have to do a Gram stain to check; 18-
24 HOURS
Blood Agar (BAP) - (answers)Used to cultivate medically significant bacteria; all-
purpose media; differential (ability to hemolyze red blood cells); includes TSA and
sheep red blood cells; RESULTS: BETA, complete hemolysis, clear zone
surrounding colonies; ALPHA, incomplete lysis, green-ish brown area surrounding
colony; GAMMA, no lysis; Don't look at colony itself to determine results; 24
HOURS
Pseudosel Agar (Cetrimide Agar) - (answers)Used to isolate and identify
Pseudomonas aeruginosa; Selective (P. aeruginosa can grow, all others inhibited
