BMS 504 (latest update ) Practical Review Questions with Complete Solutions {Grade A}

BMS 504 (latest update 2025-2026)
Practical Review Questions with Complete
Solutions {Grade A}



Which component of the Gram stain procedures colors the Gram-negative cells?
a. crystal violet

b. safranin
c. iodine

d. acetone - correct answer b. safranin


What is the purpose of using acetone alcohol during the Gram-stain procedure?
a. a fixative

b. a mordant
c. a dye

d. a decolorizing agent - correct answer d. a decolorizing agent


Prior to applying acetone alcohol to the slide, crystal violet stains _________ bacterial
cells purple

a. all
b. gram-positive

c. gram-negative
d. gram-neutral - correct answer a. all


Bacterial taxes can occur in response to which external cue(s)?

, BMS 504 (latest update 2025-2026)
Practical Review Questions with Complete
Solutions {Grade A}


a. light gradients
b. pressure gradients

c. all of the answers are correct
d. chemical gradients - correct answer c. all of the answers are correct


Directed movement by a bacterium along a chemical gradient is referred to as:

a. aerotaxis
b. chemotaxis

c. phototaxis
d. nutrotaxis - correct answer b. chemotaxis


When inoculating an MIO tube you should:

a. press the inoculating needle into the media stopping about 1/3 away from the
bottom
b. touch the top of the tube with an inoculating needle
c. press the inoculating needle into the media and touch the bottom of the tube

d. touch the top of the media with an inoculating loop - correct answer a. press the
inoculating needle into the media stopping about 1/3 away from the bottom


which type of bacteria grows strictly in the absence of oxygen?

a. obligate anaerobe
b. obligate aerobe