age 1 of 43
WGU C453 Clinical Microbiology OA ACTUAL EXAM
2025/2026 COMPLETE QUESTIONS WITH CORRECT
DETAILED ANSWERS || 100% GUARANTEED PASS
<RECENT VERSION>
Bacteria .......Answer.........Single-celled organism that do not
have a cell nucleus and the membrane-enclosed intracellular
structures found in most other cells (Prokaryotic cell).
Gram-positive Bacteria .......Answer.........Thick layer of
peptidoglycan (20-80nm across). The peptidoglycan layer is
closely attached to the outer surface of the cell membrane.
Retains crystal violet stains. Lack an outer membrane and a
periplasmic space.
Gram-negative Bacteria .......Answer.........Cell wall is thinner, but
more complex. Only 10-20% peptidoglycan. Contains an outer
,age 2 of 43
membrane, leaving a very narrow periplasmic space. Does not
retain crystal violet stain because of large quantities of
lipoproteins and lipopolysaccharides (endotoxin).
Acid-fast Bacteria .......Answer.........Cell wall is thick, but consists
of 60% lipids. Lipids make acid-fast organisms impermeable to
most other stains and protect them from acids and alkalis. Stain
as gram-positive. Grow slowly because the lipids impeded entry
of nutrients.
Endotoxin .......Answer.........Lipopolysaccharide (LPS). Part of the
outer membrane of the cell wall of gram-negative bacteria. It
can cause fever and dilates blood vessels- causing BP to drop.
Bacteria typically release this when they are dying, so killing
them increases the concentration of this toxic substance.
Antibiotics given late in the infection can cause worsening of
symptoms or even death.
,age 3 of 43
Wall-deficient Bacteria .......Answer.........Protected by a
strengthened cell membrane that contains sterols. Example:
mycobacterium paratuberculosis with Crohn's disease- a chronic
disorder of the intestine.
Coccus .......Answer.........Sphere shaped bacteria
Coccobacillus .......Answer.........Short rod shaped bacteria
(between cocci and bacilli)
Vibrio .......Answer.........Comma shaped bacteria
Bacillus .......Answer.........Rod shaped bacteria
Spirillum .......Answer.........Rigid, wavy shaped bacteria
Spirochete .......Answer.........Corkscrew shape bacteria
, age 4 of 43
Function of cell membrane .......Answer.........To regulate
movement of materials into and out of the cell by transport
mechanisms. It synthesizes cell wall components, assists with DNA
replication, secretes proteins, carries on respiration, and
captures energy as ATP.
Function of the cell wall .......Answer.........Helps maintain the
characteristic shape of the cell and prevents the cell from
bursting when fluids flow into the cell by osmosis. Lies outside the
cell membrane.
Peptidoglycan .......Answer.........Single most important component
of the bacterial cell wall.
Capsule .......Answer.........Discrete layer of polysaccharides that
protects the cell. Promotes infection by protecting the bacterial
WGU C453 Clinical Microbiology OA ACTUAL EXAM
2025/2026 COMPLETE QUESTIONS WITH CORRECT
DETAILED ANSWERS || 100% GUARANTEED PASS
<RECENT VERSION>
Bacteria .......Answer.........Single-celled organism that do not
have a cell nucleus and the membrane-enclosed intracellular
structures found in most other cells (Prokaryotic cell).
Gram-positive Bacteria .......Answer.........Thick layer of
peptidoglycan (20-80nm across). The peptidoglycan layer is
closely attached to the outer surface of the cell membrane.
Retains crystal violet stains. Lack an outer membrane and a
periplasmic space.
Gram-negative Bacteria .......Answer.........Cell wall is thinner, but
more complex. Only 10-20% peptidoglycan. Contains an outer
,age 2 of 43
membrane, leaving a very narrow periplasmic space. Does not
retain crystal violet stain because of large quantities of
lipoproteins and lipopolysaccharides (endotoxin).
Acid-fast Bacteria .......Answer.........Cell wall is thick, but consists
of 60% lipids. Lipids make acid-fast organisms impermeable to
most other stains and protect them from acids and alkalis. Stain
as gram-positive. Grow slowly because the lipids impeded entry
of nutrients.
Endotoxin .......Answer.........Lipopolysaccharide (LPS). Part of the
outer membrane of the cell wall of gram-negative bacteria. It
can cause fever and dilates blood vessels- causing BP to drop.
Bacteria typically release this when they are dying, so killing
them increases the concentration of this toxic substance.
Antibiotics given late in the infection can cause worsening of
symptoms or even death.
,age 3 of 43
Wall-deficient Bacteria .......Answer.........Protected by a
strengthened cell membrane that contains sterols. Example:
mycobacterium paratuberculosis with Crohn's disease- a chronic
disorder of the intestine.
Coccus .......Answer.........Sphere shaped bacteria
Coccobacillus .......Answer.........Short rod shaped bacteria
(between cocci and bacilli)
Vibrio .......Answer.........Comma shaped bacteria
Bacillus .......Answer.........Rod shaped bacteria
Spirillum .......Answer.........Rigid, wavy shaped bacteria
Spirochete .......Answer.........Corkscrew shape bacteria
, age 4 of 43
Function of cell membrane .......Answer.........To regulate
movement of materials into and out of the cell by transport
mechanisms. It synthesizes cell wall components, assists with DNA
replication, secretes proteins, carries on respiration, and
captures energy as ATP.
Function of the cell wall .......Answer.........Helps maintain the
characteristic shape of the cell and prevents the cell from
bursting when fluids flow into the cell by osmosis. Lies outside the
cell membrane.
Peptidoglycan .......Answer.........Single most important component
of the bacterial cell wall.
Capsule .......Answer.........Discrete layer of polysaccharides that
protects the cell. Promotes infection by protecting the bacterial
