BIOL 271 Microbiology w/ Lab | Module 4. Microbial growth, universal, selective and differential growth media

BIOL 271 Microbiology w/ Lab | Module 4. Microbial growth, universal,
selective and differential growth media
200 Questions — Review Set


Question 1
Universal growth media supports the growth of most non-fastidious microorganisms. True
or False?
✓ True
□ False
Correct Answer: True
Feedback: Universal media like nutrient agar and tryptic soy agar contain basic nutrients that support a wide
range of non-fastidious bacteria.


Question 2
Selective media allows all types of bacteria to grow equally. True or False?
□ True
✓ False
Correct Answer: False
Feedback: Selective media contain inhibitors that suppress certain organisms while allowing others to grow.


Question 3
Differential media can distinguish between bacterial species based on their metabolic
activities. True or False?
✓ True
□ False
Correct Answer: True
Feedback: Differential media contain substrates and indicators that reveal metabolic differences through
color changes.


Question 4
Blood agar is an example of a differential medium. True or False?
✓ True
□ False
Correct Answer: True
Feedback: Blood agar differentiates bacteria based on hemolytic patterns (alpha, beta, gamma hemolysis).

,Question 5
MacConkey agar is both selective and differential. True or False?
✓ True
□ False
Correct Answer: True
Feedback: MacConkey agar selects for Gram-negative bacteria and differentiates lactose fermenters from
non-fermenters.


Question 6
Eosin Methylene Blue (EMB) agar is only a selective medium. True or False?
□ True
✓ False
Correct Answer: False
Feedback: EMB agar is both selective (for Gram-negative) and differential (lactose fermentation produces
color changes).


Question 7
Selective media never contain antibiotics. True or False?
□ True
✓ False
Correct Answer: False
Feedback: Selective media often contain antibiotics, salts, or dyes to inhibit unwanted organisms.


Question 8
Mannitol salt agar selects for halophiles. True or False?
✓ True
□ False
Correct Answer: True
Feedback: Mannitol salt agar contains 7.5% NaCl, which selects for halophilic organisms like Staphylococcus
species.


Question 9
Mannitol salt agar differentiates based on lactose fermentation. True or False?
□ True
✓ False

,Correct Answer: False
Feedback: Mannitol salt agar differentiates based on mannitol fermentation, not lactose.


Question 10
Sabouraud dextrose agar is a selective medium for fungi. True or False?
✓ True
□ False
Correct Answer: True
Feedback: Sabouraud dextrose agar has a low pH that selects for fungi while inhibiting most bacteria.


Question 11
Nutrient agar is an example of a differential medium. True or False?
□ True
✓ False
Correct Answer: False
Feedback: Nutrient agar is a universal/general-purpose medium, not differential.


Question 12
LB agar is considered a universal growth medium. True or False?
✓ True
□ False
Correct Answer: True
Feedback: LB (Luria-Bertani) agar supports the growth of many bacteria, especially E. coli.


Question 13
Differential media rely solely on pH indicators for differentiation. True or False?
□ True
✓ False
Correct Answer: False
Feedback: Differential media can use various indicators including pH dyes, hemolysis, and substrate
metabolism.


Question 14
Selective media can be both liquid and solid. True or False?
✓ True

, □ False
Correct Answer: True
Feedback: Selective media exist in both broth and agar forms.


Question 15
All fastidious organisms grow well on universal media. True or False?
□ True
✓ False
Correct Answer: False
Feedback: Fastidious organisms require enriched media with specific growth factors, not universal media.


Question 16
Thayer-Martin agar is selective for Neisseria species. True or False?
✓ True
□ False
Correct Answer: True
Feedback: Thayer-Martin agar contains antibiotics that select for Neisseria gonorrhoeae and N. meningitidis.


Question 17
XLD agar differentiates based on lactose and sucrose fermentation. True or False?
✓ True
□ False
Correct Answer: True
Feedback: Xylose Lysine Deoxycholate (XLD) agar differentiates enteric pathogens based on sugar
fermentation.


Question 18
HEK agar is used to differentiate Salmonella and Shigella. True or False?
✓ True
□ False
Correct Answer: True
Feedback: Hektoen enteric agar differentiates Salmonella (black colonies) from Shigella (green colonies).


Question 19