MCB 2610 Lab final
The ______ _______ method is a quick and easy way to isolate bacteria -
correct answer ✔streak plate
In what orientation do you incubate the plates after they have been streaked?
- correct answer ✔agar half bottom
What must you do to the loop before every use? - correct answer ✔flame it
T/F: The last thing you do before leaving the lab is take off your lab coat -
correct answer ✔false
streaked plate method - correct answer ✔culture is spread out on agar to
make isolated colonies
solid media (agar plates) - correct answer ✔used to isolate bacteria
liquid culture media (broth) - correct answer ✔used to grow cells to high
densities
T/F: When making a smear of the culture, you heat fix the slide before air
drying it completely - correct answer ✔false
What is the magnification value of the ONLY objective that should come in
contact with immersion oil? - correct answer ✔100x
, Pertaining to the Gram stain, cells that retain the primary stain and appear
purple are said to be Gram - correct answer ✔positive
What cellular structure does the counterstain safranin stain? - correct answer
✔outer membrane
direct stain - correct answer ✔stains the organism itself
indirect or negative stain - correct answer ✔stains the background
simple stain - correct answer ✔use only one stain to determine cell
morphology, size and arrangement
Gram staining stains the cell __________, while spore staining stains for
__________. - correct answer ✔cell envelope, endospores
Gram Positive cell characteristics - correct answer ✔thick peptidoglycan
layer, retains crystal violet, no outer membrane
Gram Negative cell characteristics - correct answer ✔thin layer of
peptidoglycan, doesn't retain crystal violet, has outer membrane, safranin
counterstains membrane pink
Gram stain steps and time - correct answer ✔1. crystal violet, 1 minute, 2.
iodine, 1 minute, 3. ethanol, 15-30 seconds, 4. safranin, 30 seconds
Why do bacteria form endospores? - correct answer ✔under environmental
stress
The ______ _______ method is a quick and easy way to isolate bacteria -
correct answer ✔streak plate
In what orientation do you incubate the plates after they have been streaked?
- correct answer ✔agar half bottom
What must you do to the loop before every use? - correct answer ✔flame it
T/F: The last thing you do before leaving the lab is take off your lab coat -
correct answer ✔false
streaked plate method - correct answer ✔culture is spread out on agar to
make isolated colonies
solid media (agar plates) - correct answer ✔used to isolate bacteria
liquid culture media (broth) - correct answer ✔used to grow cells to high
densities
T/F: When making a smear of the culture, you heat fix the slide before air
drying it completely - correct answer ✔false
What is the magnification value of the ONLY objective that should come in
contact with immersion oil? - correct answer ✔100x
, Pertaining to the Gram stain, cells that retain the primary stain and appear
purple are said to be Gram - correct answer ✔positive
What cellular structure does the counterstain safranin stain? - correct answer
✔outer membrane
direct stain - correct answer ✔stains the organism itself
indirect or negative stain - correct answer ✔stains the background
simple stain - correct answer ✔use only one stain to determine cell
morphology, size and arrangement
Gram staining stains the cell __________, while spore staining stains for
__________. - correct answer ✔cell envelope, endospores
Gram Positive cell characteristics - correct answer ✔thick peptidoglycan
layer, retains crystal violet, no outer membrane
Gram Negative cell characteristics - correct answer ✔thin layer of
peptidoglycan, doesn't retain crystal violet, has outer membrane, safranin
counterstains membrane pink
Gram stain steps and time - correct answer ✔1. crystal violet, 1 minute, 2.
iodine, 1 minute, 3. ethanol, 15-30 seconds, 4. safranin, 30 seconds
Why do bacteria form endospores? - correct answer ✔under environmental
stress
