Correct Answers
When performing a chemorepellent assay, why does the zone where bacteria have
moved away from the disc get larger as the concentration of toxin gets higher?
a. the higher the concentration of the toxin the more bacteria die close to the disc, so
the bigger the zone.
b. the higher the concentration of the toxin the more toxic it is so bacteria move away
faster
c. the higher the concentration of the toxin the further it will diffuse from the disc, so the
further the bacterium must move to avoid it - Answer-c
When microbiologists talk about bacterial growth, they are typically referring to an
increase in bacterial cell numbers and not in cell size.
True
False - Answer-True
You have isolated a newly discovered mesophilic bacterium. You find that at 38 degrees
Celsius, the bacteria grow to 1x10^6 cells. If you move this organism to 10 degrees
Celsius, you would expect the generation time of this organism to
a. increase
b. decrease
c. stay the same - Answer-increase
People shouldn't overuse antibiotics because antibiotics induce resistance
a. true
b. false - Answer-b. false
If you want to sanitize a sample, it is better to use:
a. 70% alcohol
b. 90% alcohol
c. 100% alcohol - Answer-a. 70% alcohol
Which part of the body is likely to have microbial normal flora?
, a. mouth
b. lungs
c. genital tract
d. stomach
e. these will all have normal flora - Answer-e.
Bonnie Bassler and her research group study ______________
a. endosymbiont theory
b. oceanic pollution
c. gene transfer
d. quorum sensing - Answer-d.
Which of the following symbiotic relationships best describes that which 'Fertis the
Fistulated Steer' experiences?
a. mutualistic
b. commensal
c. toxic
d. parasitism - Answer-a.
Which of the following bacterial toxins are actively secreted by the bacterium?
a. superantigens
b. neurotoxins
c. enterotoxins
d. endotoxins
e. all except D - Answer-e
Which of the following are eukaryotic microbes?
a. viruses
b. protozoa
c. bacteria
d. yeasts
e. b and d - Answer-e
Protozoa are considered "transitional" organisms because they may not contain all the
usual membrane-bound organelles you would expect to find in a eukaryotic cell
true
false - Answer-true
You just landed a position as a Graduate Teaching Assistant in a microbiology
laboratory class and are gradin laboratory notebooks. How would you grade this
student's lab book entry?