UAMS Microbiology Exam #1 Updated Questions
and Answers (2026) | Latest Practice Review
with Detailed Explanations | Grade A+
• Gram stain, culture, organism identification, and antimicrobial susceptibility. -
✓✓In the health care system, the physician consults with the patient and retrieves a
specimen. The specimen is then sent to the lab, a report is generated, and the report
is sent to the physician. What are the 4 things included in the report from the micro
lab?
• Specimen collection. It is a tube closed on the bottom and open at the top with
swabs inserted into the culturette container. -✓✓What is a culturette used for?
• Collect the specimen with a culturette tube, plate it using either an agar or broth
medium, incubate the culture, and then ID. Determine antimicrobial susceptibility
and report results. -✓✓What is the complete procedure done by the lab for
collecting and then identifying an organism?
• Coccus, coccobacillus, vibrio, bacillus, spirillum, and spirochete. -✓✓What are
the different morphologies of bacteria?
• Coccus (one single colony), diplococci (two colonies), staphylococci (multiple
colonies in a triangle shape), streptococci (multiple colonies in a linear row),
sarcina (multiple colonies that can be on top of one another in a square shape), and
tetrad (four colonies in a square). -✓✓What are the different bacterial
arrangements for cocci?
• Rod shaped. The genus (Bacillus anthracis). Single bacillus, diplobacilli,
streptobacilli, and palisade (rods laid side by side, forming a fence-like appearance;
,can also be V-shaped). -✓✓What does bacillus or bacilli refer to? What about
Bacillus? What are the bacilli arrangements?
• Bacteria that is capable of altering its morphology to take on many different
shapes. -✓✓What does the term pleomorphic refer to? Ex. Pleomorphic bacilli
• Spores are cells with very thick walls that can survive many extremes, allowing a
bacterium protection in order to preserve its genetic material. -✓✓What are spores
and what do they allow a bacterium, such as bacilli with spores?
• Filamentous and fusiform. -✓✓What are the two different forms of bacilli rods?
• Hans Christian Gram. Crystal violet, iodine, decolorizer, and safranin. The cell
wall structure of the bacteria is what determines if it is gram pos or neg. The thick
peptidoglycan layer on gram pos MOs retains the crystal violet-iodine complex.
On gram neg MOs, there is only a thin layer of peptidoglycan under a layer of
lipids. The lipid layer retains the stain and the decolorizer then dissolves the lipid
layer, removing the crystal violet-iodine complex. -✓✓Who invented the Gram
stain and staining method? What are the reagents involved? How is Gram stain
able to work? What makes some bacteria gram pos and others neg?
• Safranin. Once the decolorizer dissolves the lipid layer holding the crystal violet-
iodine complex, the safranin is able to stain the thin peptidoglycan layer
underneath, causing the bacteria to appear pink. The pink bacteria can then be
identified as Gram neg. -✓✓What is the counter stain that is used alongside Gram
stain to identify the Gram neg bacteria? How does this work?
• Cells from a culture are taken and spread over a thin area of a slide and then heat
fixed. The smear doesn't need to be too thin or too thick, otherwise it will be
unable to be read properly. Smears are heat fixed using a bunsen burner, an electric
, incinerator, or methanol. This is done to kill the bacteria on the slide, prevent
bacteria from washing off the slide, and allowing the smear to take up stain better.
-✓✓What is smear? What is important when preparing a smear? How are smears
heat fixed and why?
• Place the slide on a staining rack and cover the smear with crystal violet solution.
Let stand for 30-60 seconds. Rinse with tap water to remove the crystal violet, then
shake off excess water. Cover the smear with Gram's iodine and let stand for 30-60
seconds. Rinse with water, then shale off excess. Decolorize the smear with
acetone-alcohol and rinse with water as soon as the purple/blue color no longer
runs off the slide. *Be careful to not over or under decolorize* Shake off excess
water and counterstain with safranin for 30 seconds, rinse with water, and dry slide
by air or by blotting. -✓✓What is the Gram staining procedure?
• Gram neg cells such as human cells will appear washed out and gram pos bacteria
will appear gram neg or partially stained. Gram neg cells such as human cells will
appear dark red / purple and other gram neg bacteria appear gram pos. -✓✓What
will happen is the decolorizer is left on too long? What about under-decolorized?
• Damaged cells are a potential problem when looking at older culture, they will
not take up stain. This can be due to antibiotics. Overheating a slide distorts cells
from their normal shape, causing them to look weird when viewing. Improper
reagent use can be a source of error when one is omitted or they are used in the
wrong order. Excessive rinsing can wash out the crystal violet or crystal violent
iodine complex away, Prolonged counterstaining might cause the crystal violet
complex to be leached from the Gram pos MOs. -✓✓How will damaged cells pose
as a source of error when staining? How does overheating a slide pose as a source
of error? What about improper reagent use? What about excessive rinsing and
prolonged counterstaining?
• Media is used to culture specimens, isolate bacteria, biochemicals used for
identification, and used for antibiotic susceptibility.
and Answers (2026) | Latest Practice Review
with Detailed Explanations | Grade A+
• Gram stain, culture, organism identification, and antimicrobial susceptibility. -
✓✓In the health care system, the physician consults with the patient and retrieves a
specimen. The specimen is then sent to the lab, a report is generated, and the report
is sent to the physician. What are the 4 things included in the report from the micro
lab?
• Specimen collection. It is a tube closed on the bottom and open at the top with
swabs inserted into the culturette container. -✓✓What is a culturette used for?
• Collect the specimen with a culturette tube, plate it using either an agar or broth
medium, incubate the culture, and then ID. Determine antimicrobial susceptibility
and report results. -✓✓What is the complete procedure done by the lab for
collecting and then identifying an organism?
• Coccus, coccobacillus, vibrio, bacillus, spirillum, and spirochete. -✓✓What are
the different morphologies of bacteria?
• Coccus (one single colony), diplococci (two colonies), staphylococci (multiple
colonies in a triangle shape), streptococci (multiple colonies in a linear row),
sarcina (multiple colonies that can be on top of one another in a square shape), and
tetrad (four colonies in a square). -✓✓What are the different bacterial
arrangements for cocci?
• Rod shaped. The genus (Bacillus anthracis). Single bacillus, diplobacilli,
streptobacilli, and palisade (rods laid side by side, forming a fence-like appearance;
,can also be V-shaped). -✓✓What does bacillus or bacilli refer to? What about
Bacillus? What are the bacilli arrangements?
• Bacteria that is capable of altering its morphology to take on many different
shapes. -✓✓What does the term pleomorphic refer to? Ex. Pleomorphic bacilli
• Spores are cells with very thick walls that can survive many extremes, allowing a
bacterium protection in order to preserve its genetic material. -✓✓What are spores
and what do they allow a bacterium, such as bacilli with spores?
• Filamentous and fusiform. -✓✓What are the two different forms of bacilli rods?
• Hans Christian Gram. Crystal violet, iodine, decolorizer, and safranin. The cell
wall structure of the bacteria is what determines if it is gram pos or neg. The thick
peptidoglycan layer on gram pos MOs retains the crystal violet-iodine complex.
On gram neg MOs, there is only a thin layer of peptidoglycan under a layer of
lipids. The lipid layer retains the stain and the decolorizer then dissolves the lipid
layer, removing the crystal violet-iodine complex. -✓✓Who invented the Gram
stain and staining method? What are the reagents involved? How is Gram stain
able to work? What makes some bacteria gram pos and others neg?
• Safranin. Once the decolorizer dissolves the lipid layer holding the crystal violet-
iodine complex, the safranin is able to stain the thin peptidoglycan layer
underneath, causing the bacteria to appear pink. The pink bacteria can then be
identified as Gram neg. -✓✓What is the counter stain that is used alongside Gram
stain to identify the Gram neg bacteria? How does this work?
• Cells from a culture are taken and spread over a thin area of a slide and then heat
fixed. The smear doesn't need to be too thin or too thick, otherwise it will be
unable to be read properly. Smears are heat fixed using a bunsen burner, an electric
, incinerator, or methanol. This is done to kill the bacteria on the slide, prevent
bacteria from washing off the slide, and allowing the smear to take up stain better.
-✓✓What is smear? What is important when preparing a smear? How are smears
heat fixed and why?
• Place the slide on a staining rack and cover the smear with crystal violet solution.
Let stand for 30-60 seconds. Rinse with tap water to remove the crystal violet, then
shake off excess water. Cover the smear with Gram's iodine and let stand for 30-60
seconds. Rinse with water, then shale off excess. Decolorize the smear with
acetone-alcohol and rinse with water as soon as the purple/blue color no longer
runs off the slide. *Be careful to not over or under decolorize* Shake off excess
water and counterstain with safranin for 30 seconds, rinse with water, and dry slide
by air or by blotting. -✓✓What is the Gram staining procedure?
• Gram neg cells such as human cells will appear washed out and gram pos bacteria
will appear gram neg or partially stained. Gram neg cells such as human cells will
appear dark red / purple and other gram neg bacteria appear gram pos. -✓✓What
will happen is the decolorizer is left on too long? What about under-decolorized?
• Damaged cells are a potential problem when looking at older culture, they will
not take up stain. This can be due to antibiotics. Overheating a slide distorts cells
from their normal shape, causing them to look weird when viewing. Improper
reagent use can be a source of error when one is omitted or they are used in the
wrong order. Excessive rinsing can wash out the crystal violet or crystal violent
iodine complex away, Prolonged counterstaining might cause the crystal violet
complex to be leached from the Gram pos MOs. -✓✓How will damaged cells pose
as a source of error when staining? How does overheating a slide pose as a source
of error? What about improper reagent use? What about excessive rinsing and
prolonged counterstaining?
• Media is used to culture specimens, isolate bacteria, biochemicals used for
identification, and used for antibiotic susceptibility.
