GCU Microbiology Lab Midterm Exam Questions With
Complete Solutions
Acid-fast versus nonacid-fast cell Correct Answers Acid-fast
cell
Red
-Primary dye-Carbol Fuschin
-Decolorizer-Acid Alcohol
-Secondary Dye-Methylene blue
(Final color-red)
Purpose of the acid-fast stain- To differentiate between acid fast
and non-acid fast bacteria
Contain Mycolic acid which resists staining.
Nonacid-fast cell
Blue
Do not contain Mycolic acid.
Air Dry Correct Answers letting slide dry by sitting
As you rush to be in time for the Microbiology lab, you
accidentally spill coffee on your lab coat and the white fabric
gets stained. Is this a biological stain or simply a compound that
is capable of imparting color to the fabric? Explain your
reasoning. Correct Answers This is a compound stain. A
biological stain would be differential staining. No, it is not,
because this stain is not used to observe the microorganisms.
, Aseptic Methods Correct Answers In order to prevent
contaminating microbes from entering cultures, we use aseptic
methods to prevent such. The streak for isolation technique is
the most common aseptic technique used to obtain discrete
colonies of bacteria given in a mixed broth.
Bacteria culture Correct Answers The microbial cell growth on
nutrient media. Bacterial growth.
Bacterial Colony Correct Answers A cluster of closely backed
cells that originates from a single cell. Site of bacterial growth;
cluster of microorganism growing on agar surface.
Bacterial Media Correct Answers Allows us to isolate
bacterium, identify morphology.
Biological stain (Benzene) Correct Answers Organic colorless
solvent; chromosphore-chem group that imparts color to the
benzene; auxchrome-has an ionization property, makes stain
biological.
Brightfield Microscope Correct Answers a microscope that
allows light rays to pass directly to the eye free from deflection
Bunsen Burner Correct Answers A small adjustable gas burner
used in laboratories. Used for heating, sterilization, and
combustion.
Complete Solutions
Acid-fast versus nonacid-fast cell Correct Answers Acid-fast
cell
Red
-Primary dye-Carbol Fuschin
-Decolorizer-Acid Alcohol
-Secondary Dye-Methylene blue
(Final color-red)
Purpose of the acid-fast stain- To differentiate between acid fast
and non-acid fast bacteria
Contain Mycolic acid which resists staining.
Nonacid-fast cell
Blue
Do not contain Mycolic acid.
Air Dry Correct Answers letting slide dry by sitting
As you rush to be in time for the Microbiology lab, you
accidentally spill coffee on your lab coat and the white fabric
gets stained. Is this a biological stain or simply a compound that
is capable of imparting color to the fabric? Explain your
reasoning. Correct Answers This is a compound stain. A
biological stain would be differential staining. No, it is not,
because this stain is not used to observe the microorganisms.
, Aseptic Methods Correct Answers In order to prevent
contaminating microbes from entering cultures, we use aseptic
methods to prevent such. The streak for isolation technique is
the most common aseptic technique used to obtain discrete
colonies of bacteria given in a mixed broth.
Bacteria culture Correct Answers The microbial cell growth on
nutrient media. Bacterial growth.
Bacterial Colony Correct Answers A cluster of closely backed
cells that originates from a single cell. Site of bacterial growth;
cluster of microorganism growing on agar surface.
Bacterial Media Correct Answers Allows us to isolate
bacterium, identify morphology.
Biological stain (Benzene) Correct Answers Organic colorless
solvent; chromosphore-chem group that imparts color to the
benzene; auxchrome-has an ionization property, makes stain
biological.
Brightfield Microscope Correct Answers a microscope that
allows light rays to pass directly to the eye free from deflection
Bunsen Burner Correct Answers A small adjustable gas burner
used in laboratories. Used for heating, sterilization, and
combustion.
