2025-2026) Practical Review Questions
with Complete Solutions {Grade A}
Parts of a light microscope - correct answer Glass lens (eyepiece or ocular lens), glass
lens (objective lens) stage with slide, glass lens (condenser), light source
Proper nomenclature - correct answer genus is capitalized and species is lowercased
total magnification - correct answer objective lens x ocular lens
ex. 10X objective lens coupled with a 10X ocular lens would give 100X total
magnification
gram negative stain - correct answer red/pink
gram positive stain - correct answer retain crystal violet and stain purple
Gram negative tests - correct answer -Gram stain
-Morphology
-Lactose fermentation
-Oxidase test
-Indole test
-Urea test
-Motility
-Hydrogen sulfide test
, BMS 504 Exam study Guide (latest update
2025-2026) Practical Review Questions
with Complete Solutions {Grade A}
Indole test - correct answer Tests organisms ability to breakdown Tryptophan to
indole. Utilized Kovac's reagent. Positive - Red, Negative- No color change
Methyl Red Test Results - correct answer positive - red
negative - yellow
Measures the production of mixed acids by fermentation of glucose
Voges-Proskauer Test - correct answer *Postive VP Test:*
-color change to red, 2.3-butanediol fermentation (acetoin produced).
*Negative VP Test:*
-No color change, no 2,3 butanediol fermentation (acetoin is not produced).
Measures the production of the neutral end product acetoin by fermentation of
glucose
Citrate test results - correct answer positive: blue
negative: green
ability of an organism to use citrate as its sole carbon source (instead of utilizing
glucose)
oxidase test results - correct answer Color change to purple is positive. (Cue tip test)
identifies bacteria that have cytochrome oxidase (e.g., Pseudomonas)