Practical Review Questions with Complete
Solutions {Grade A}
what does growth look like in nutrient broth? - correct answer cloudy=growth
clear=no growth
colony morphology - correct answer circular, irregular, filamentous, elevated
staphylococcus aureus - correct answer gram positive
cocci
purple
escherichia coli - correct answer gram negative
rod
pink
selective media - correct answer inhibits growth of certain bacteria and allows other
bacteria to grow
differential medium - correct answer specific chemicals to indicate bacteria that
posses or lacks a biochemical process
MSA plate - correct answer mannitol salt agar
, BMS 504 Exam (latest update 2025-2026)
Practical Review Questions with Complete
Solutions {Grade A}
tests for mannitol fermentation
selective agent: NaCl, prevents growth of most gram negative
differentiating agent: mannitol and pH indicator (mannitol fermentation leads to
yellow color change or organge)
EMB plate - correct answer Eosin methylene blue agar
selective agent: eosin and methylene blue prevent growth of most gram positive
differential agent: lactose and pH indicator, lactose fermentation purple or green
color change
proteus mirabilis - correct answer gram negative
rod
pink
bacillus subtilis - correct answer gram positive
rod
purple
serratia marcescens - correct answer gram negative
rod
pink
, BMS 504 Exam (latest update 2025-2026)
Practical Review Questions with Complete
Solutions {Grade A}
pseudomonas aeruginosa - correct answer gram negative
rod
pink
kirby bauer test - correct answer tests antimicrobial properties of 6 different
compounds
compounds are on disks (placed with forceps) and are placed on top of a lawn or
spread plate of bacteria
spread plate is done using a hockey stick (dipped in ethanol and then passed through
flame to sterilize)
measure zones of inhibition after incubation
from center of disk to edge of area with no growth diameter (in mm)
viable plate count - correct answer way to quantify the concentration of bacteria
using dilution