1. Aseptic technique refers to
The microbial inoculum placed into a test tube or onto a petridish.
The prevention of contamination.
The isolation of on species of bacteria from a mixedcommunity.
The autoclave or sterilizing procedures.
Cleanliness in the laboratory.
2. This method can be used to sterilize a liquid media withoutharming heat labile ingredients.
Autoclaving
Pasteurization
Freezing
Cold filtration
Addition of ethylene oxide to the media
3. Consider two parallel cultures. They are in all ways identicalexcept that one contains test substance X. You observe that abacterium you are studying grows equally well in both media.Therefore, test substance X is ___________.
A macronutrient
A micronutrient
An essential nutrient
A toxin
Not a nutrient
4. A microbe uses CO2 as its sole source of carbon andoxidizes H2 as its source of energy, to whichnutritional group does this microbe belong?
Photoautotroph
Chemoorganotroph
Photoorganotroph
Chemoautotroph
5. A mutant bacterium does not produce a functional hydroxamate.This bacterium would have difficulty obtaining ___________.
Phosphate
Iron
Ammonia
Thiosulfate
Hydrogen sulfide
6. A medium containing methylene blue and incubated at 55º Cenriches for ______.
Mesophilic mycoplasma
Hyperthermophilic gram negatives
Gram positives
Thermophilic gram negatives
Thermophilic gram positives
7. Bacterium “A” has a growth rate constant of 4doubles/hour. Bacterium “B” has a generation time of0.25 hours/double. Which bacterium grows faster?
“A” grows faster than “B”
“B” grows faster than “A”
A” and “B” grow at the same rate
No conclusion can be made from this data
8. Assume you inoculated 100 cells into 100 ml of nutrient broth.You then inoculated 100 cells of the same species into 200 ml ofnutrient broth. After incubation for 12 hours, you should have
More cells in the 100 ml
More cells in the 200 ml
The same number of cells in both.
9. _________ halodurics use K+ as their osmolyte.
All
Some
No
10. A medium containing 3.2% NaCl and 0.025% phenethyl alcoholwould enrich for _________.
Nonhalophiles
Gram-negative halodurics
Gram-negative halophiles
Gram-positive hyperhalophiles
Gram-positive halophiles