1. The phylogenetic tree of the living world is derived from sequencing of
A. chromosomal DNA
B. 16S or 18S ribosomal RNA
C. transfer RNA
D. ribosomal proteins
E. none of the above
2. Which of the following cellular features is found in Archaea, but not in
Eukarya or Bacteria?
A. procaryotic cellular organization
B. 70S
ribosomes
C. cell walls consisting of murein
D. membranes consisting of
ether-linked isoprenoids
E. transcription and translation are coupled
3. Which of the following is a characteristic of protein synthesis in both
Archaea and Eukarya?
A. Transcription and translation are coupled.
B.
The initiator tRNA is methionine.
C. The initiator tRNA is
N-formyl-methionine.
D. Protein synthesis is inhibited by tetracycline.
E. None of the above
4. A metabolic characteristic found in the Bacteria that never occurs in
Archaea or Eukarya is
A. anoxygenic photosynthesis
B. oxygenic
photosynthesis
C. lithotrophy
D. halophily
E. thermophily
5. The approximate size of a typical bacterial cell (e.g. E. coli or
Staphylococcus) is
A. 100 nanometers
B. 1 micrometer
C. 10
micrometers
D. 10-3 centimeters
E. 0.01 millimeters
6. The macromolecule that makes up the highest percentage of the dry weight
of bacterial cells is
A. DNA
B. lipopolysaccharide
C. peptidoglycan
D. protein
E. RNA
7. The genetic and biochemical similarities between existing cyanobacteria
and eukaryotic chloroplasts is evidence that
A. Archaea evolved into
eukaryotes
B. photosynthesis first evolved in an anaerobic environment
C. oxygenic photosynthesis first evolved in eukaryotes
D. chloroplasts
and cyanobacteria share a common evolutionary ancestor
E. cyanobacteria
arose from chloroplasts which escaped from plant cells
Questions 8 -11 refer to the following diagram of the muropeptide subunit of the cell wall peptidoglycan of E. coli.
9. The pointer to the bond whose formation is inhibited by beta-lactam
antibiotics is
A. II
B. III
C. V
D. VI
E. none of the
above
10. The arrow pointing to the bond that is cleaved by lysozyme is
A. II
B. III
C. IV
D. V
E. none of the above
11. Which component of this peptidoglycan is a diamino dicarboxylic acid ?
A. D-glutamate
B. D-glutamine
C. L-lysine
D. L-glycine
E.
Diaminopimelic acid
12. The function of peptidoglycan in the cell wall of the E.coli is to
A. serve as a permeability barrier to all solutes except H2O
B. prevent osmotic lysis of the cell protoplast
C. regulate the passage
of solutes through the cell wall
D. regulate the passage of solutes into and
out of the cell
E. none of the above
13. The interpeptide bridge of Gram-positive bacterial murein (e.g. the
pentaglycine bridge in Staphylococcus aureus) connects
A.
Diaminopimelic acid to D-alanine
B. L-lysine to D-alanine
C. L-lysine to
D-glutamate
D. Diaminopimelic acid to l-lysine
E. D-lysine to
L-lysine
Questions 14-17 refer to the following schematic drawing of the ultrastructure of the flagellum of E. coli (after Adler).
15. The flagellar motor (M) ring is indicated by pointer
A. F
B. B
C. C
D. D
E. E
16. Which component of the flagellar apparatus did Pate find to be absent in
the gliding bacterium, Cytophaga?
A. A
B. B
C. C
D. D
E. E and F
17. Which part of the flagellar apparatus is absent in the spirochetes and in
Gram-positive bacteria?
A. A
B. B
C. C and D
D. E and F
E.
none of the above
18. Most of the spiral-shaped and curved bacteria are motile by means of
polar flagella. From this information what would you predict is their most
likely habitat?
A. water
B. soil
C. marine sediments
D. skin of
animals
E. intestinal tracts of animals
19. The endoflagella (axial filaments) of spirochetes are also referred to as
periplasmic flagella because
A. they reside between the inner membrane and
an outer membrane of the cell
B. they contain the entire flagellar apparatus
except the filament, and hence, can only be used for gliding motility
C.
they are located uniformly on the surface of the cell
D. although the cells
are motile, these structures are not involved in the characteristic type of
swimming movement of spirochetes
E. they are cellular appendages continuous
with the plasma membrane and cell wall
20. The function of the sex (F) pilus of Escherichia coli involves
A. transport of nutrients
B. attachment of cells to inert surfaces
C. movement of cells in a type of twitching motion
D. transfer of DNA
between bacteria during conjugation
E. organization and folding of the
bacterial chromosome within the cytoplasm
21. The capsule of procaryotic cells, including slime layers and glycocalyx,
may be used to
A. digest nutrients on the surfaces of cells
B. attach
mating cells during the process of conjugation
C. attach cells to solid
surface and initiate formation of a biofilm
D. provide buoyancy for cells in
aquatic habitats
E. regulate the passage of solutes into and out of the
cell
Questions 22 -26 refers to the drawing below of the ultra structure of the cell surface of Escherichia coli.
22. The structure shown by pointer III is
A. omp C or omp F porin
B.
omp A protein
C. Braun lipoprotein
D. Lipid A
E. flagellar
L-ring
23. The function of this structure (pointer III above) is
A. active
transport of solutes across the plasma membrane
B. support of the bacterial
flagellum
C. maintain the lateral stability of the outer membrane
D.
anchor the outer membrane to the underlying peptidoglycan sheet
E. allow
passage of solutes through the outer membrane
24. Bracket B defines the limits of the
A. outer membrane
B. plasma
membrane
C. cytoplasm
D. periplasm
E. capsule
25. Which component is lipopolysaccharide?
A. I
B. II
C. V
D.
D
E. E
26. Which component is peptidoglycan?
A. A
B. IV
C. C
D. D
E. E
27. Gram-negative bacteria are typically less susceptible to penecillin than
are Gram-positive bacteria because
A. they lack a transport system for
penicillin
B. they degrade penicillin in the periplasmic space by means of
penicillinase enzymes
C. they lack peptidoglycan in their cell wall
D.
their peptidoglycan is chemically modified to be resistant to attack by
penicillin
E. their outer membrane is an effective permeability
barrier
28. Polybetahydroxybutyric acid and glycogen are formed by bacterial cells as
A. reserves of carbon and energy
B. reserves of nitrogen
C. waste
material
D. molecular ligands to attach bacterial cells to surface receptors
E. none of the above
29. A procaryote possessing carboxysomes and chlorosomes as inclusions in its
cytoplasm probably has this type of metabolism.
A. photoautotrophic
B.
photoheterotrophic
C. lithoautotrophic
D. heterotrophic
E.
fermentative
30. This is the common inclusion observed in purple and green bacteria and
lithotrophs such as Thiobacillus.
A. sulfur
B. polyphosphate
C. parasporal crystals
D. PHB granules
E. magnetosomes
31. Compared to the vegetative cells that form them, bacterial endospores
have
A. a surface structure consisting of additional protective layers
B. no ribosomes
C. appendages in the form of flagella and pili
D.
relatively high rates of respiration
E. relatively reduced resistance to
boiling and desiccation
32. A chemical substance found in bacterial endospores that is not found in
vegetative cells is
A. diaminopimelic acid
B. dipicolinic acid
C.
ketodeoxyoctonoic acid
D. D-glutamate
E. L-lysine
33. Which of the following is not a function of the plasma membrane of
procaryotes?
A. retention of cytoplasmic constituents as a selective
permeability barrier
B. active transport of nutrients from the environment
C. storage of reserve carbohydrates and lipids
D. electron transport and
O2 uptake during aerobic respiration
E. light harvesting and electron
transport during photosynthesis
34. The passage of molecules (solutes) across the bacterial plasma membrane
from a region of low concentration to a region of high concentration is called
A. antiport (exchange diffusion)
B. facilitated diffusion
C. osmosis
D. group translocation
E. active transport
35. Binding protein-dependent transport systems are used by bacterial cells
to
A. pass hydrophilic molecules of low molecular weight through porins in
the outer membrane
B. pass electrons through a sequence of carriers in the
plasma membrane
C. secrete proteins across the plasma membrane into the
periplasmic space
D. establish a proton motive force on the surface of the
membrane
E. take up nutrients, such as sugars and amino acids, from the
environment
36. Transport of glucose using a group translocation system rather than a
binding protein dependent transport system is advantageous to a bacterium
because
A. glucose, a disaccharide, is initially cleaved into its
monosaccharide constituents during the transport process
B. glucose can be
transported into the cell against an external concentration gradient
C.
glucose is phosphorylated as it traverses the membrane which accomplishes the
first step of glycolysis and conserves ATP
D. energy is not required for
transport
E. it has the effect of decreasing the internal osmolarity within
the cytoplasm of the cell
Questions 37-40 refer to the following diagram of the ultrastructure of the plasma membrane of Escherichia coli.
37. The lactose transport system (lactose permease) is an example of
A. a
uniport process
B. an antiport process
C. a symport process
D. an
ion-driven transport system
E. two of the above
38. Proton motive force is established on the membrane by means of
A.
lactose transport
B. ATP synthesis
C. electron transport processes in
the membrane
D. Ca++ export
E. all of the above
39. Proton motive force on the membrane is utilized during the process of
A. flagellar rotation
B. proline transport
C. ATP synthesis
D.
Na+ export
E. all of the above
40. Suppose you could inhibit the transmembranous ATPase enzyme of the
bacterium without inhibiting the membrane electron transport system. Which
effect(s) on the bacterium would you expect to encounter?
A. loss in ability
to make ATP by electron transport phosphorylation
B. loss in ability to
establish pmf on the membrane
C. loss in ability to transport sugars or
amino acids using ion (proton)-driven transport systems
D. loss in the
ability to swim
E. two of the above
41. Some cyanobacteria are able to grow in the atmosphere, in the presence of
light, in solutions that contain only a few mineral salts (tapwater, for
example). Physiological (metabolic) characteristics that permit their growth
under these conditions include
A. ability to fix CO2
B.
ability to fix N2
C. ability to convert light energy into
chemical energy
D. lack of any growth factor requirements
E. all of the
above
42. Which of the following statements regarding bacterial growth factors is
not true?
A. They are needed as sources of carbon and energy by
heterotrophic bacteria.
B. Although not proteins, they may be constituents
of proteins.
C. Their need in bacterial nutrition results from a missing or
blocked metabolic pathway.
D. They may function as vitamins or coenzymes in
metabolism.
E. Growth factors are not required by all bacteria.
43. In what type of bacterial culture medium listed below would blood never
be a component?
A. an enrichment medium
B. a complex medium
C. a
selective medium
D. a chemically-defined medium
E. a solid (as opposed
to liquid) medium
44. Lack of the enzymes catalase and superoxide dismutase may explain why
certain bacteria are
A. unable to produce oxygen radicals when exposed to
O2
B. able to grow in the absence of O2
C. killed
by exposure to O2
D. able to respire in the presence of
O2
E. able to respire in the absence of O2
45. An Archaean that is an obligate anaerobe and an extreme thermophile A.
can grow at 37 degrees in the absence of O2
B. can grow at 37
degrees in the presence of O2
C. can grow at 85 degrees in the
presence of O2
D. can grow at 85 degrees in the absence of
O2
E. none of the above
46. A bacterium that is a psychrotroph and a facultative anaerobe
A. can
grow at 5 degrees in the absence of O2
B. can grow at 5 degrees
in the presence of O2
C. can grow at 25 degrees in the presence
of O2
D. all of the above
E. none of the above
47. A procaryote, Halobacterium in the Great Salt Lake, requires NaCl
in excess of 4 molar in order to grow, and is therefore classified nutritionally
as a(n)
A. alkalophile (alkaliphile)
B. lithotroph
C. phototroph
D. extreme halophile
E. extreme thermophile
Questions 48-50 refer to the following set of data.
A standard bacterial growth curve can be plotted from the following information:
A bacterium was inoculated into fresh broth medium and incubated at 37 degrees under aerobic conditions. Viable cell counts (plate counts) over a period of 24 hours resulted in findings of 100 cells/ml at the time of inoculation, 100 cells/ml at 2 hours, 100 cells/ml at 4 hours, 103 cells/ml at 6 hours, 104 cells/ml at 8 hours, 106 cells/ml at 12 hours, 108 cells/ml at 16 hours, 109 cells/ml at 18 hours, 109 cells/ml at 20 hours, 109 cells/ml at 22 hours, 108 cells/ml at 24 hours.
48. What coordinates are used to label the graph that plots the bacterial
growth curve?
A. growth rate vs time
B. growth rate vs generation time
C. optical density vs time
D. number of bacteria vs time
E. log
number of viable cells vs time
49. The length of the lag phase of the culture is
A. 2 hours
B. 4
hours
C. 8 hours
D. 14 hours
E. 18 hours
50. The generation time of this bacterial culture is approximately
A. 18
minutes
B. 30 minutes
C. 36 minutes
D. 48 minutes
E. 72 minutes
51. Pasteurization of milk using heat accomplishes
A. complete
elimination of all microorganisms in the milk
B. reduction in the total
number of organisms but no reduction or elimination of pathogens in the milk
C. elimination of pathogens but no elimination or reduction in the number of
nonpathogens in the milk
D. killing all potential pathogens in milk except
Mycobacterium tuberculosis
E. reduction in the total number of
microorganisms and elimination of potential pathogens in the milk
Questions 69-73 refer to the following sequences of reactions from bacterial
metabolic pathways.
arg = arginine
cob = cobalamin (vit B12)
his = histidine
thi =
thiamin (vit B1)
CM = chloramphenicol (r = resistant; s = sensitive)
A. Glucose minimal medium plus cob, arg
B. glucose minimal medium plus
cob, thi
C. glucose minimal medium plus cob, his
D. glucose minimal
medium plus his, thi, CM
E. glucose minimal medium plus cob, CM
122. The largest density (greatest number) of bacteria on the surfaces of the
human body is found on (in) the
A. skin
B. lower gastrointestinal tract
C. stomach
D. lower respiratory tract
E. mouth
123. The predominant bacterium in the lower GI tract (colon) of adults is
A. Bifidobacterium
B. E. coli
C. Bacteroides
D. Enterococcus faecalis
E. Methanobacter
124. The most important benefit that the human gastrointestinal flora provide
for their host is
A. digestion of dietary cellulose
B. a low grade
toxemia
C. production of dietary protein
D. antagonism against
colonization by potential pathogens
E. production of antibodies
125. The main carrier site on the human body for strains of potentially
pathogenic Staphylococcus aureus is the
A. oral cavity
B. throat
(posterior nasopharynx)
C. nasal membranes
D. gastrointestinal tract
E. vagina
126. The carrier site for pathogenic Neisseria meningitidis is the
A. conjunctiva
B. nasopharynx
C. urogenital tract
D. blood
E. meninges
127. This bacterium, although usually not considered as normal flora,
frequently colonizes the stomach and is thought to be the cause of gastric and
duodenal ulcers.
A. Lactobacillus acidophilus
B. Pseudomonas
aeruginosa
C. Escherichia coli
D. Vibrio cholerae
E. Helicobacter pylori
128. Silver nitrate or an antibiotic is put into the eyes of newborn infants
to prevent infection by
A. Doderlein's bacillus (Lactobacillus
acidophilus)
B. Herpes simplex virus
C. Neisseria gonorrhoeae
D. Chlamydia trachcomatis
E. two of the above
129. A characteristic of Streptococcus mutans that allows it to
initiate dental plaque and dental caries is:
A. the ability to attach
specifically to the pellicle of the tooth
B. the ability to utilize sucrose
as a source of carbon and energy
C. the ability to produce a dextran capsule
D. the ability to produce lactic aci
E. all of the above
130. The fimbriae of enterotoxigenic E. coli are essential to the
bacterium when it causes disease because
A. they are needed for initial
attachment of the bacteria to the gastrointestinal epithelium
B. they
activate host adenylate cyclase enzymes leading to disruption of cellular
permeability
C. they make the bacteria resistant to phagocytic killing and
digestion by white blood cells
D. they convert GI tract components (bile) to
substances which provoke
symptoms of disease
E. they allow the bacteria
to swim "upstream" against the peristaltic action of the GI tract thereby
remaining established in the GI tract
131. The fibrin coat that can be formed by coagulase-positive staphylococci
and the hyaluronic acid capsule of Streptococcus pyogenes are pathogenic
strategies to
A. promote colonization of a host
B. cause direct damage
to host cells during pathogenesis
C. hide bacterial antigens from the host
immune tissues
D. survive as intracellular parasites
E. alter or change
their surface antigens within the course of an infection
132. Leukocidins are
A. enzymes contained in the lysosomes of phagocytes
to kill ingested bacteria
B. proteins produced by bacteria that kill
closely-related bacteria
C. proteases produced by bacteria which destroy
host immunoglobulins
D. enterotoxins produced by Staphylococcus
aureus involved in food-borne disease
E. substances produced by pyogenic
bacteria that kill phagocytes
133. The streptococcal invasin which behaves as a "spreading factor" by
breaking down the framework of connective tissues is called
A. collagenase
B. streptokinase
C. streptolysin
D. erythrogenic toxin (pyogenic
exotoxin)
E. hyaluronidase
134. A primary determinant of virulence in Streptococcus pyogenes,
which is involved in adherence, resistance to phagocytosis and antigenic
variation, is
A. streptokinase
B. lipopolysaccharide (endotoxin)
C.
M-protein
D. Protein A
E. coagulase
135. Which of the following statements that relate to bacterial exotoxins and
endotoxins is true?
A. Exotoxins are proteins; endotoxins are
lipopolysaccharides.
B. Exotoxins are typically structural (cell wall)
components of Gram-positive bacteria.
C. Endotoxins can never be released by
the cells that produce them.
D. Endotoxins cause their toxicity through an
enzymatic mechanism of action.
E. In the host, endotoxins are destroyed by
the enzyme lysozyme.
136. The substrate for the enzymatic (A) component of diphtheria toxin and
the cholera toxin is
A. NAD
B. cyclic AMP
C. the regulatory proteins
of the eukaryotic adenylate cyclase complex
D. ATP
E. elongation factor
2 (EF-2)
137. The large volume of fluid lost by diarrhea during infection with
Vibrio cholerae
A. is a consequence of fluid replacement during
treatment of the disease and does not result directly from activity of the
cholera toxin
B. results from electrolytes binding to the intestinal
enterocytes which upsets their water retention capability
C. is caused when
the vibrios bind to the intestinal epithelium and physically or mechanically
block the uptake of fluids by the gut epithelial cells
D. follows activation
of adenylate cyclase by cholera toxin and the subsequent effect of cyclic AMP on
water and salt balances of the host cells
E. results from neurotoxic effects
of the cholera toxin on the central nervous system
138. The similarity between the toxic shock syndrome toxin (TSST), the staph
enterotoxins, and the erythrogenic toxin (pyogenic exotoxin) is
A. they are
all produced by Staphylococcus aureus
B. they stimulate the immune
system in a similar manner as superantigens
C. the pathology of the diseases
that they cause is identical
D. they are all neurotoxins
E. they are the
same (identical) toxin produced by three different organisms
139. Both the botulinum toxin and the tetanus toxin
A. are produced by
Bacillus anthracis
B. act in the central nervous system
C. act in
the peripheral nervous system
D. are Zn++ dependent protease enzymes
E.
two of the above
140. Two bacterial toxins which behave as adenylate cyclase enzymes (i.e.,
are inherent adenylate cyclase enzymes) in eukaryotic cells are
A. cholera
toxin and pertussis Ptx toxin
B. pertussis AC toxin and Anthrax EF toxin
C. staphylococcal TSST and staphylococcal enterotoxin
D. diphtheria
toxin and Pseudomonas exotoxin A
E. staphylococcal leukocidin and
streptococcal streptokinase
141. The characteristic substance in the core (R) region of the endotoxin
molecule that is often assayed (measured) to determine the presence of bacterial
endotoxin in a biological substance is
A. ketodeoxyoctonoic acid (KDO)
B. N-acetylmuramic acid (NAM)
C. Lipid A
D. dideoxyhexose
E.
N-acetylglucosamine (NAG)
142. Injection of endotoxin into an animal stimulates the following
response(s):
A. an immunological response resulting in antibody production
B. an inflammatory response resulting in fever
C. activation of
complement leading to inflammation
D. activation of the Hageman factor
leading to intravascular coagulation and hemorrhage
E. all of the
above
143. The portion of the endotoxin molecule that is believed to be responsible
for most of its toxic properties is
A. lipid A
B. core polysaccharide
C. specific "O" polysaccharide
D. B +C
E. A + B + C
144. Active immunity against diphtheria is accomplished by
A.
administration diphtheria antitoxin or antiserum
B. immunization with the
diphtheria toxoid
C. recovery from the disease diphtheria
D. transfer of
antibodies from mother to offspring via the colostrum (milk)
E. two of the
above
145. Passive immunity to tetanus in a susceptible host would be accomplished
by
A. recovery from the disease tetanus
B. injection with tetanus toxin
C. injection with tetanus toxoid (as in the DTP vaccine)
D.
administration of serum from an individual with active immunity to tetanus
E. two of the above
146. A newborn infant is passively immune due to
A. transplacental
transfer of maternal antibodies in utero
B. exposure to foreign antigens
during birth
C. activation of the immune system which occurs at birth
D.
immediate colonization by a normal flora
E. recovery from diseases acquired
after birth
147. Bacterial substances that are antigenic to an animal
A. typically
have a high molecular weight (>10,000 daltons)
B. will cause the
formation of antibodies
C. are often the surface components of the bacterial
cells
D. are "foreign" molecules to the animal
E. all of the above
148. The type of cell in an animal that is the precursor of phagocytes and
lymphocytes is
A. bone marrow stem cell
B. lymphoblast
C.
monocyte
D. B cell
E. pre T cell
149. During a primary immune response antibody molecules (immunoglobulins)
are synthesized by
A. T cells
B. B cells
C. macrophages
D.
plasma cells
E. none of the above
150. The predominant immunoglobulin in the serum of an animal is
A. IgA
B. IgD
C. IgE
D. IgG
E. IgM
151. The most important activity of IgA on the surface of the intestinal or
respiratory mucosa is to
A. stimulate the development of an immune response
B. activate an inflammatory response
C. block colonization of the
surfaces by pathogens
D. stimulate the development of a T-cell response
E. block the production of IL-1 by macrophages
152. Circulating antibody molecules participate in anti-bacterial host
defense by
A. opsonizinzation of bacterial cells
B. activation of
complement on the bacterial surface
C. agglutination (immobilization) of
bacterial cells
D. neutralization bacterial toxins
E. all of the
above
153. The function of cytotoxic T cells (TC) during an immunological response
is to
A. act as antigen presenting cells for the induction of the immune
response
B. kill cells which show a new antigen on their surface
C.
produce lymphokines that activate macrophages
D. produce IL-2 that
stimulates the development of T cells
E. none of the above
154. The main function of interleukin-l (IL-l) during an immunological
response is to
A. cause fever and inflammation
B. stimulate
TH2 cells
C. stimulate macrophages
D. enhance phagocytosis
E. induce differentiation of B cells into plasma cells
155. Which of the following cell types is not involved in the initiation and
mediation of the antibody-mediated immune (AMI) response?
A. macrophages (as
antigen presenting cells)
B. B-lymphocytes
C. plasma cells
D. TC
cells
E. TH2 cells
156. The cell-mediated immune (CMI) response is responsible for
A.
killing cells infected by viruses
B. killing tumor cells
C. rejection of
tissue transplants
D. all of the above
E. none of the above