Practical Review Questions with Complete
Solutions {Grade A}
What lab safety level is this lab? - correct answer BLS 2
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
, BMS 504 Exam (latest update 2025-2026)
Practical Review Questions with Complete
Solutions {Grade A}
MSA plate - correct answer mannitol salt agar
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
, BMS 504 Exam (latest update 2025-2026)
Practical Review Questions with Complete
Solutions {Grade A}
pink
pseudomonas aeruginosa - correct answer gram negative
rod
pink
complex vs defined media - correct answer complex: contains several chemicals exact
composition is unknown (nutrient broth and agar)
Defined: all chemicals are known
quadrant streak - correct answer allows you to isolate bacterial colonies or pure
cultures
making max number of streaks without overlapping
like a dilution
Important pieces of microscope - correct answer objective lens (ones we turn), stage
(where slide goes), course focus (big nob that moves stage up and down), fine focus
(small nob that focuses picture), light source
focal point - correct answer where a lens converges parallel light rays