OPENSTAX MICROBIOLOGY CHAPTER
9 EXAM QUESTIONS AND ANSWERS.
VERIFIED 2025/2026.
Differential Media - ANS make it easy to distinguish colonies of different microbes by
changing the color of the colony or the color of the medium.
Enrichment Media - ANS encourages growth of desired microbe that represent a fraction of
the organisms present in an inoculation.
Selective Media - ANS Inhibit growth of unwanted organisms and support thee growth of
organisms of interest.
Halotolerant - ANS Do not need a high concentration of salt to grow, but can still survive and
divide in the presence of salt.
Halophiles - ANS require high salt concentration for growth.
Thermophiles - ANS Optimal temep 50c
important for biotechnology
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
, Listeria monocytogens - ANS Grows in refrigerators on/ in
-soft cheese
-deli meat
-hummus
-ice cream
Does not harm humans but can cross the placenta of a pregnant woman and kill the fetus.
Psychophile
Psychophiles - ANS Cold loving, optimal temp at 15c
Mesophiles - ANS Middle Loving, Optimal temp 20-45c
Most human pathogens.
Normal microbiota
Helicbactor pylori - ANS neutrophile, survives in the stomach because it creates a micro
environment where the pH is nearly neutral.
Does it by urease with breaks down euro two form NH4+ and CO2
Alkaliphiles - ANS grow optimally at pH above 8.5
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
9 EXAM QUESTIONS AND ANSWERS.
VERIFIED 2025/2026.
Differential Media - ANS make it easy to distinguish colonies of different microbes by
changing the color of the colony or the color of the medium.
Enrichment Media - ANS encourages growth of desired microbe that represent a fraction of
the organisms present in an inoculation.
Selective Media - ANS Inhibit growth of unwanted organisms and support thee growth of
organisms of interest.
Halotolerant - ANS Do not need a high concentration of salt to grow, but can still survive and
divide in the presence of salt.
Halophiles - ANS require high salt concentration for growth.
Thermophiles - ANS Optimal temep 50c
important for biotechnology
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
, Listeria monocytogens - ANS Grows in refrigerators on/ in
-soft cheese
-deli meat
-hummus
-ice cream
Does not harm humans but can cross the placenta of a pregnant woman and kill the fetus.
Psychophile
Psychophiles - ANS Cold loving, optimal temp at 15c
Mesophiles - ANS Middle Loving, Optimal temp 20-45c
Most human pathogens.
Normal microbiota
Helicbactor pylori - ANS neutrophile, survives in the stomach because it creates a micro
environment where the pH is nearly neutral.
Does it by urease with breaks down euro two form NH4+ and CO2
Alkaliphiles - ANS grow optimally at pH above 8.5
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
