MBIO 3812 Exam 3 2025/2026 Exam
Questions and Verified Answers |
1
Already Graded A+
coliform can ferment... - 🧠 ANSWER ✔✔lactose
what does the presence of coliforms indicate? - 🧠 ANSWER ✔✔whether a water
sample has been contaminated with fecal matter
what is used to determine if a water sample is contaminated with coliforms? - 🧠
ANSWER ✔✔Most Probable Number (MPN) test
MPN calculates... - 🧠 ANSWER ✔✔1. total coliform counts
2. E. coli counts
what was the objective of our MPN? - 🧠 ANSWER ✔✔whether duck pond water
was contaminated with E. coli (coliform)
LTB - 🧠 ANSWER ✔✔Laurel Tryptose Broth
LTB contains - 🧠 ANSWER ✔✔1. Lauryl sulfate: inhibits growth of non-coliforms
100% GUARANTEED PASS
COPYRIGHT©PROFFKERRYMARTIN 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE.
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,2. lactose: coliforms can ferment this
3. Durham tube: indicates lactose fermentations
2
LTB is... - 🧠 ANSWER ✔✔selective for coliforms and gives a PRESUMPTIVE
determination for their presence
after first incubation period, LTB broths in MPN are examined for what two
things? - 🧠 ANSWER ✔✔1. growth (considered + for later calculations)
2. gas bubble
indicate PROBABLE coliform
2 loops of culture from every + (growth) LTB tube goes into... - 🧠 ANSWER ✔✔1.
Brilliant Green Lactose Bile broth (BGLB)
2. E. coli broth (EC)
Brilliant Green Lactose Bile broth contains - 🧠 ANSWER ✔✔1. Lactose:
fermentable by coliforms
2. Durham tube: gas indicates lactose fermentation (+ result if gas)
3. 2% bile: selective for coliforms
100% GUARANTEED PASS
COPYRIGHT©PROFFKERRYMARTIN 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE.
PRIVACY STATEMENT. ALL RIGHTS RESERVED
, why is BGLB important? - 🧠 ANSWER ✔✔it is selective & CONFIRMS presence
of coliforms
3
3 E. coli broth components - 🧠 ANSWER ✔✔1. Lactose: fermentable by coliforms
2. Durham tube: gas indicates lactose fermentation (+ result)
3. bile salts: selective for coliforms
how is EC broth selective for E. coli? - 🧠 ANSWER ✔✔when incubated at 45°C
P value in MPN? - 🧠 ANSWER ✔✔P = total # of + BGLB OR EC
Vn value in MPN? - 🧠 ANSWER ✔✔Vn = combined volume of sample in LTB
tubes that produced - BGLB or EC
Va value in MPN? - 🧠 ANSWER ✔✔Va = combined volume of sample in all LTB
tubes
MPN calculation - 🧠 ANSWER ✔✔MPN/100 ml = 100P ÷ √(VnVa)
selective media - 🧠 ANSWER ✔✔contains compounds that can prevent the growth
of certain bacterial species
how is media selective? - 🧠 ANSWER ✔✔inhibitors
100% GUARANTEED PASS
COPYRIGHT©PROFFKERRYMARTIN 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE.
PRIVACY STATEMENT. ALL RIGHTS RESERVED
Questions and Verified Answers |
1
Already Graded A+
coliform can ferment... - 🧠 ANSWER ✔✔lactose
what does the presence of coliforms indicate? - 🧠 ANSWER ✔✔whether a water
sample has been contaminated with fecal matter
what is used to determine if a water sample is contaminated with coliforms? - 🧠
ANSWER ✔✔Most Probable Number (MPN) test
MPN calculates... - 🧠 ANSWER ✔✔1. total coliform counts
2. E. coli counts
what was the objective of our MPN? - 🧠 ANSWER ✔✔whether duck pond water
was contaminated with E. coli (coliform)
LTB - 🧠 ANSWER ✔✔Laurel Tryptose Broth
LTB contains - 🧠 ANSWER ✔✔1. Lauryl sulfate: inhibits growth of non-coliforms
100% GUARANTEED PASS
COPYRIGHT©PROFFKERRYMARTIN 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE.
PRIVACY STATEMENT. ALL RIGHTS RESERVED
,2. lactose: coliforms can ferment this
3. Durham tube: indicates lactose fermentations
2
LTB is... - 🧠 ANSWER ✔✔selective for coliforms and gives a PRESUMPTIVE
determination for their presence
after first incubation period, LTB broths in MPN are examined for what two
things? - 🧠 ANSWER ✔✔1. growth (considered + for later calculations)
2. gas bubble
indicate PROBABLE coliform
2 loops of culture from every + (growth) LTB tube goes into... - 🧠 ANSWER ✔✔1.
Brilliant Green Lactose Bile broth (BGLB)
2. E. coli broth (EC)
Brilliant Green Lactose Bile broth contains - 🧠 ANSWER ✔✔1. Lactose:
fermentable by coliforms
2. Durham tube: gas indicates lactose fermentation (+ result if gas)
3. 2% bile: selective for coliforms
100% GUARANTEED PASS
COPYRIGHT©PROFFKERRYMARTIN 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE.
PRIVACY STATEMENT. ALL RIGHTS RESERVED
, why is BGLB important? - 🧠 ANSWER ✔✔it is selective & CONFIRMS presence
of coliforms
3
3 E. coli broth components - 🧠 ANSWER ✔✔1. Lactose: fermentable by coliforms
2. Durham tube: gas indicates lactose fermentation (+ result)
3. bile salts: selective for coliforms
how is EC broth selective for E. coli? - 🧠 ANSWER ✔✔when incubated at 45°C
P value in MPN? - 🧠 ANSWER ✔✔P = total # of + BGLB OR EC
Vn value in MPN? - 🧠 ANSWER ✔✔Vn = combined volume of sample in LTB
tubes that produced - BGLB or EC
Va value in MPN? - 🧠 ANSWER ✔✔Va = combined volume of sample in all LTB
tubes
MPN calculation - 🧠 ANSWER ✔✔MPN/100 ml = 100P ÷ √(VnVa)
selective media - 🧠 ANSWER ✔✔contains compounds that can prevent the growth
of certain bacterial species
how is media selective? - 🧠 ANSWER ✔✔inhibitors
100% GUARANTEED PASS
COPYRIGHT©PROFFKERRYMARTIN 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE.
PRIVACY STATEMENT. ALL RIGHTS RESERVED
