BIO 261 - EXAM 3 - PENNY POWELL
EXAM WITH CORRECT QUESTIONS
AND ANSWERS 2025
a. GI tract - CORRECT-ANSWERS-consists of the stomach, small intestine, and large
intestine.
b. -responsible for digestion of food, absorption of nutrients, and production of
nutrients by the indigenous microbial flora.
c. the acidity of the stomach and the duodenum of the small intestine (pH 2) -
CORRECT-ANSWERSprevents many organisms from colonizing the GI tract
d. firmicutes, bacteroidetes, and actinobacteria - CORRECT-ANSWERScommon in
the gastric fluid
e. firmicutes and proteobacteria - CORRECT-ANSWERScommon in the mucus layer
of the stomach
f. helicobacter pylori - CORRECT-ANSWERSwhen present, found in the gastric
mucosa
,g. intestinal microorganisms - CORRECT-ANSWERScarry out a variety of essential
metabolic reactions that produce various compounds
h. the large intestine/colon - CORRECT-ANSWERS-essentially an in vivo
fermentation vessel, with microbiota using nutrients derived from the digestion
of food
i. -most organisms are restricted to the lumen, while others are in the mucosal
layer
j. vitamin production, modification of steroids, and amino acid biosynthesis -
CORRECT-ANSWERSmany microbial metabolites or transformation products that
can be generated in the gut have significant influence on host physiology, such
as
k. oral cavity - CORRECT-ANSWERSa complex, heterogeneous microbial habitat
l. saliva - CORRECT-ANSWERScontains antimicrobial enzymes
m. high concentrations of nutrients near surfaces in the mouth - CORRECT-
ANSWERSpromote localized microbial growth in the mouth
n. enamel - CORRECT-ANSWERS-mineral matrix in the tooth
,o. -surrounds living tissue, dentin, and pulp
p. upper respiratory tract - CORRECT-ANSWERSmicrobes thrive in the
q. the air during breathing - CORRECT-ANSWERSbacteria continually enter the
upper respiratory tract from
r. mucus of the nasal and oral passages - CORRECT-ANSWERSmost bacteria that
enter the upper respiratory tract are trapped in the ___ and expelled with nasal
secretions or swallowed and then killed in the stomach
s. ciliated mucosal cells - CORRECT-ANSWERSthe lower respiratory tract has no
normal microbiota in healthy adults because ____ move particles up and out of
the lungs
t. multiply and cause disease - CORRECT-ANSWERSaltered conditions can cause
potential pathogens in the urethra to
u. E. coli and P. mirabilis - CORRECT-ANSWERSfrequently cause urinary tract
infections in women
v. weakly acidic; glycogen - CORRECT-ANSWERSthe vagina of the adult female is
___ and contains significant amounts of ___
, w. Lactobacillus acidophilus - CORRECT-ANSWERS-a resident organism in the
vagina
x. -ferments glycogen in the vagina, producing lactic acid
y. lactic acid - CORRECT-ANSWERSmaintains a local acidic environment
z. skin surface - CORRECT-ANSWERSvaries greatly in chemical composition and
moisture content
aa. dry skin, moist skin, and sebaceous skin - CORRECT-ANSWERSthree
microenvironments of the skin
bb. environmental factors (weather), host factors (puberty and personal hygiene), and
each environment shows a unique microbiota - CORRECT-ANSWERScomposition
of microbes on the skin is influenced by
cc. dental plaque - CORRECT-ANSWERS-a biofilm formed by cells
dd. -has Streptococcus and other fermenting bacteria that produce acid
ee. wear down the tooth enamel - CORRECT-ANSWERSthe acid produced by
fermenters
EXAM WITH CORRECT QUESTIONS
AND ANSWERS 2025
a. GI tract - CORRECT-ANSWERS-consists of the stomach, small intestine, and large
intestine.
b. -responsible for digestion of food, absorption of nutrients, and production of
nutrients by the indigenous microbial flora.
c. the acidity of the stomach and the duodenum of the small intestine (pH 2) -
CORRECT-ANSWERSprevents many organisms from colonizing the GI tract
d. firmicutes, bacteroidetes, and actinobacteria - CORRECT-ANSWERScommon in
the gastric fluid
e. firmicutes and proteobacteria - CORRECT-ANSWERScommon in the mucus layer
of the stomach
f. helicobacter pylori - CORRECT-ANSWERSwhen present, found in the gastric
mucosa
,g. intestinal microorganisms - CORRECT-ANSWERScarry out a variety of essential
metabolic reactions that produce various compounds
h. the large intestine/colon - CORRECT-ANSWERS-essentially an in vivo
fermentation vessel, with microbiota using nutrients derived from the digestion
of food
i. -most organisms are restricted to the lumen, while others are in the mucosal
layer
j. vitamin production, modification of steroids, and amino acid biosynthesis -
CORRECT-ANSWERSmany microbial metabolites or transformation products that
can be generated in the gut have significant influence on host physiology, such
as
k. oral cavity - CORRECT-ANSWERSa complex, heterogeneous microbial habitat
l. saliva - CORRECT-ANSWERScontains antimicrobial enzymes
m. high concentrations of nutrients near surfaces in the mouth - CORRECT-
ANSWERSpromote localized microbial growth in the mouth
n. enamel - CORRECT-ANSWERS-mineral matrix in the tooth
,o. -surrounds living tissue, dentin, and pulp
p. upper respiratory tract - CORRECT-ANSWERSmicrobes thrive in the
q. the air during breathing - CORRECT-ANSWERSbacteria continually enter the
upper respiratory tract from
r. mucus of the nasal and oral passages - CORRECT-ANSWERSmost bacteria that
enter the upper respiratory tract are trapped in the ___ and expelled with nasal
secretions or swallowed and then killed in the stomach
s. ciliated mucosal cells - CORRECT-ANSWERSthe lower respiratory tract has no
normal microbiota in healthy adults because ____ move particles up and out of
the lungs
t. multiply and cause disease - CORRECT-ANSWERSaltered conditions can cause
potential pathogens in the urethra to
u. E. coli and P. mirabilis - CORRECT-ANSWERSfrequently cause urinary tract
infections in women
v. weakly acidic; glycogen - CORRECT-ANSWERSthe vagina of the adult female is
___ and contains significant amounts of ___
, w. Lactobacillus acidophilus - CORRECT-ANSWERS-a resident organism in the
vagina
x. -ferments glycogen in the vagina, producing lactic acid
y. lactic acid - CORRECT-ANSWERSmaintains a local acidic environment
z. skin surface - CORRECT-ANSWERSvaries greatly in chemical composition and
moisture content
aa. dry skin, moist skin, and sebaceous skin - CORRECT-ANSWERSthree
microenvironments of the skin
bb. environmental factors (weather), host factors (puberty and personal hygiene), and
each environment shows a unique microbiota - CORRECT-ANSWERScomposition
of microbes on the skin is influenced by
cc. dental plaque - CORRECT-ANSWERS-a biofilm formed by cells
dd. -has Streptococcus and other fermenting bacteria that produce acid
ee. wear down the tooth enamel - CORRECT-ANSWERSthe acid produced by
fermenters
