Microbiology (Openstax) Final Exam
Questions with Complete Rationales
2026/2027 Updated.
A bacterial chromosome is located in which of the following?
a.the nucleoid region
b.the nucleus
c.the thylakoids
d.the capsule - Answer a.the nucleoid region
A bacterium possessing a tuft of flagella at one end of its cell is called
a.Lophotrichous
b.Peritrichous
c.Monotrichous
d.Amphitrichous - Answer Lophotrichous
Acid-fast cell walls contain high concentrations of
a.peptidoglycan
b.teichoic acid
c.mycolic acid
d.pseudomurein - Answer mycolic acid
All of the following are found in the cell walls of gram-positive bacteria EXCEPT __________.
a.teichoic acid
b.peptidoglycan
c.lipoteichoic acid
d.lipid A - Answer Lipid A
Bacteria divide by
a.binary fission
b.Mitosis
c.spore formation
d.Budding - Answer Bynary fission
,Chemotaxis refers to the ability of microorganisms to __________.
a.survive under adverse conditions
b.attach to solid surfaces
c.move in a wavelike motion
d.move toward or away from chemical stimuli - Answer move toward or away from chemical
stimuli
Elementary bodies are found in the phylum
a.Chlamydiae
b.Chloroflexi
c.Planctomycetes
d.Bacteroidetes - Answer Chlamydiae
Enteric bacteria would most likely be found in which environment?
a.warm, tropical soil
b.intestinal tract of an animal
c.human skin
d.unpasteurized milk and apple juice - Answer intestinal tract of an animal
In chloroplasts, chlorophyll is contained in flattened sacs called
a.Cisternae
b.Vacuoles
c.Cristae
d.Thylakoids - Answer Thylakoids
Peptic ulcers in humans are commonly caused by members of the genus
a.Shigella
b.Enterobacter
c.Helicobacter
d.Salmonella - Answer helicobacter
Rickettsias differ from chlamydias in that only rickettsias
a.form spores
b.are intracellular parasites
c.are Gram-negative
,d.require an arthropod for transmission - Answer require an arthropod for transmission
Spherical bacteria that divide and remain attached in chainlike patterns are called __________.
a.Staphylococci
b.Tetrads
c.Streptococci
d.Spirochetes - Answer Streptococci
The two domains of prokaryotes are
a.Bacteria and Protista
b.Archaea and Fungi
c.Bacteria and Archaea
d.Bacteria and Fungi - Answer Bacteria and Archaea
What are the sizes of two subunits used to compose prokaryotic ribosomes?
a.30S + 50S
b.30S + 40S
c.20S + 50S
d.40S + 60S - Answer 30S + 50S
Which is NOT true of the rickettsias?
a.They are classified as beta-proteobacteria
b.They are obligate intracellular parasites
c.They can cause human diseases often characterized by a rash
d.They are typically transmitted by insects and ticks - Answer They are classified as beta-
proteobacteria
Which member of the gammaproteobacteria is a potential cause of pneumonia and can be
found in warm-water supply lines and air conditioning cooling towers?
a.Legionella
b.Klebsiella
c.Coxiella
d.Salmonella - Answer Legionella
Which of the following genera is NOT a member of the phylum Actinobacteria?
, a.Streptomyces
b.Lactobacillus
c.Propionibacterium
d.Mycobacterium - Answer lactobacillus
Which of the following is NOT a member of the order Enterobacteriales?
a.Salmonella
b.Pseudomonas
c.Shigella
d.Escherichia - Answer Pseudonomas
Which of the following is NOT an enteric?
a.Escherichia
b.Enterobacter
c.Campylobacter
d.Salmonella - Answer Campylobacter
Which of the following processes requires energy?
a.active transport
b.facilitated diffusion
c.simple diffusion
d.osmosis - Answer Active transport
Which of the following statements is TRUE for prokaryotes?
a.They are multicellular organisms
b.They generally lack organelles (such as nuclei)
c.Their cell walls are chemically simple
d.Their DNA is associated with histone proteins - Answer They generally lack organelles (such
as nuclei)
Which of the following structures allows a cell to survive adverse environmental conditions?
a.Endospore
b.Carboxysome
c.Capsule
d.Gas vacuole - Answer Endospore
Questions with Complete Rationales
2026/2027 Updated.
A bacterial chromosome is located in which of the following?
a.the nucleoid region
b.the nucleus
c.the thylakoids
d.the capsule - Answer a.the nucleoid region
A bacterium possessing a tuft of flagella at one end of its cell is called
a.Lophotrichous
b.Peritrichous
c.Monotrichous
d.Amphitrichous - Answer Lophotrichous
Acid-fast cell walls contain high concentrations of
a.peptidoglycan
b.teichoic acid
c.mycolic acid
d.pseudomurein - Answer mycolic acid
All of the following are found in the cell walls of gram-positive bacteria EXCEPT __________.
a.teichoic acid
b.peptidoglycan
c.lipoteichoic acid
d.lipid A - Answer Lipid A
Bacteria divide by
a.binary fission
b.Mitosis
c.spore formation
d.Budding - Answer Bynary fission
,Chemotaxis refers to the ability of microorganisms to __________.
a.survive under adverse conditions
b.attach to solid surfaces
c.move in a wavelike motion
d.move toward or away from chemical stimuli - Answer move toward or away from chemical
stimuli
Elementary bodies are found in the phylum
a.Chlamydiae
b.Chloroflexi
c.Planctomycetes
d.Bacteroidetes - Answer Chlamydiae
Enteric bacteria would most likely be found in which environment?
a.warm, tropical soil
b.intestinal tract of an animal
c.human skin
d.unpasteurized milk and apple juice - Answer intestinal tract of an animal
In chloroplasts, chlorophyll is contained in flattened sacs called
a.Cisternae
b.Vacuoles
c.Cristae
d.Thylakoids - Answer Thylakoids
Peptic ulcers in humans are commonly caused by members of the genus
a.Shigella
b.Enterobacter
c.Helicobacter
d.Salmonella - Answer helicobacter
Rickettsias differ from chlamydias in that only rickettsias
a.form spores
b.are intracellular parasites
c.are Gram-negative
,d.require an arthropod for transmission - Answer require an arthropod for transmission
Spherical bacteria that divide and remain attached in chainlike patterns are called __________.
a.Staphylococci
b.Tetrads
c.Streptococci
d.Spirochetes - Answer Streptococci
The two domains of prokaryotes are
a.Bacteria and Protista
b.Archaea and Fungi
c.Bacteria and Archaea
d.Bacteria and Fungi - Answer Bacteria and Archaea
What are the sizes of two subunits used to compose prokaryotic ribosomes?
a.30S + 50S
b.30S + 40S
c.20S + 50S
d.40S + 60S - Answer 30S + 50S
Which is NOT true of the rickettsias?
a.They are classified as beta-proteobacteria
b.They are obligate intracellular parasites
c.They can cause human diseases often characterized by a rash
d.They are typically transmitted by insects and ticks - Answer They are classified as beta-
proteobacteria
Which member of the gammaproteobacteria is a potential cause of pneumonia and can be
found in warm-water supply lines and air conditioning cooling towers?
a.Legionella
b.Klebsiella
c.Coxiella
d.Salmonella - Answer Legionella
Which of the following genera is NOT a member of the phylum Actinobacteria?
, a.Streptomyces
b.Lactobacillus
c.Propionibacterium
d.Mycobacterium - Answer lactobacillus
Which of the following is NOT a member of the order Enterobacteriales?
a.Salmonella
b.Pseudomonas
c.Shigella
d.Escherichia - Answer Pseudonomas
Which of the following is NOT an enteric?
a.Escherichia
b.Enterobacter
c.Campylobacter
d.Salmonella - Answer Campylobacter
Which of the following processes requires energy?
a.active transport
b.facilitated diffusion
c.simple diffusion
d.osmosis - Answer Active transport
Which of the following statements is TRUE for prokaryotes?
a.They are multicellular organisms
b.They generally lack organelles (such as nuclei)
c.Their cell walls are chemically simple
d.Their DNA is associated with histone proteins - Answer They generally lack organelles (such
as nuclei)
Which of the following structures allows a cell to survive adverse environmental conditions?
a.Endospore
b.Carboxysome
c.Capsule
d.Gas vacuole - Answer Endospore
