Aseptic technique refers and consider two parallel cultures | Homework Helpers

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
        AIDition 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