Chapter 11 Characterizing and Classifying Prokaryotes
11.1 Multiple Choice Questions
1) Pleomorphic bacteria
A) have a slightly curved rod shape.
B) are flexible.
C) reproduce by snapping division.
D) are roughly spherical.
E) vary in size and shape.
2) Which of the following bacterial arrangements is the result of snapping division?
A) tetrads
B) palisades
C) strepto-
D) sarcinae
E) staphylo-
3)
The arrangement represented in Figure 11.1 is typical of which of the following genera of
bacteria?
A) Bacillus
B) Corynebacterium
C) Escherichia
D) Actinomyces
E) Streptococcus
4) Contamination with ________ is a concern because they are highly resistant to killing.
A) archaea
B) endospores
C) pleomorphs
D) vegetative cells
E) vibrios
5) Endospores
A) are bacterial reproductive structures.
B) may be produced when nutrients are scarce.
C) are produced by bacteria, algae, and fungi.
D) are resistant to everything except radiation.
E) can last for only about 10 years.
6) Bergey’s Manual of Systematic Bacteriology contains
A) classification schemes for prokaryotes.
B) treatments for bacterial diseases.
C) recipes for bacterial growth media.
D) genetic sequences of prokaryotes.
E) rules for naming new bacterial species.
7) Which of the following characteristics distinguish the archaea from the bacteria?
A) cell wall composition
B) ribosomal RNA (rRNA) sequences
C) the deoxyribonucleotides in the DNA
D) cytoplasmic membrane lipids
E) cell wall composition, cytoplasmic membrane lipids, and rRNA sequences
8) The archaea known as halophiles
A) require temperatures above 45∘C to survive.
B) require salt concentrations of 9% or greater to survive.
C) are members of the phylum Euryarchaeota.
D) are members of the Euryarchaeota and require temperatures above 45∘C.
E) are members of the Euryarchaeota and require salt concentrations above 9%.
9) The ________ are the largest known group of archaea.
A) thermophiles
B) halophiles
C) cyanobacteria
D) methanogens
E) hyperthermophiles
10) Which of the following types of microbes might be found in a boiling hot spring?
A) hyperthermophiles
B) phototrophic bacteria
C) methanogens
D) non-thermophiles
E) halophiles
11) Which of the following groups of bacteria lives in environments similar to those that may
have existed on the early Earth?
A) deeply branching bacteria
B) cyanobacteria
C) mycoplasmas
D) thermophiles
E) proteobacteria
12) Aerobic cyanobacteria carry out the reactions of nitrogen fixation in
A) akinetes.
B) endospores.
C) heterocysts.
D) chloroplasts.
E) lamellae.
13) Some cyanobacteria reproduce by means of
A) akinetes.
B) endospores.
C) budding.
D) meiosis.
E) fragmentation.
14) Bacteria in the phylum Firmicutes are distinguished from the phylum Actinobacteria on the
basis of
A) their Gram stain reaction.
B) the high G + C content of their DNA.
C) their spiral shapes.
D) the low G + C content of their DNA.
E) the presence of LPS in their membranes.
15) Which of the following diseases is NOT associated with bacteria that form endospores?
A) tetanus
B) anthrax
C) gangrene
D) botulism
E) toxic shock syndrome
16) Mycoplasmas are pleomorphic because they
A) have no cell walls.
B) are low G + C content Gram-positive bacteria.
C) exhibit snapping division.
D) have sterols in their cytoplasmic membranes.
E) produce endospores.
17) Which of the following bacterial genera produce(s) endospores?
A) Bacillus
B) Clostridium
C) Lactobacillus
D) both Bacillus and Lactobacillus
E) both Bacillus and Clostridium
18) Which of the following bacterial genera includes species that protect areas of the body such
as the intestinal tract and the vagina from invasion by pathogens?
A) Staphylococcus
B) Listeria
C) Lactobacillus
D) Mycobacterium
E) Corynebacterium
19) Which of the following groups of bacteria is named for its resemblance to fungi?
A) Corynebacterium
B) Actinomyces
C) Clostridium
D) Lactobacillus
E) Staphylococcus
20) Which of the following bacterial genera is used for the degradation of environmental
pollutants?
A) Actinomyces
B) Streptomyces
C) Corynebacterium
D) Rhizobium
E) Nocardia
21) Which of the following is NOT associated with bacteria in the genus Streptomyces?
A) the “musty” smell of soil
B) nutrient recycling in soil
C) antibiotic production
D) microbial antagonism
E) protection of plants against caterpillars
22) What feature of mycobacteria is responsible for the unusually slow growth of these
bacteria?
A) Their low tolerance for oxygen retards their growth.
B) They cannot fully metabolize carbohydrates and must rely on fermentation.
C) They have limited numbers of ribosomes so protein production is slow.
D) The mycolic acid in their cell walls requires signification metabolic investment.
E) They lack a cell wall and are extremely fragile.
23) Members of the ________ are Gram-positive bacteria that have a distinctive process for
cell separation known as “snapping division.”
A) Actinomycetes
B) Clostridium
C) Corynebacterium
D) Mycoplasma
E) Rhizobium
24) Members of which of the following genera are the most common sexually transmitted
bacteria in the United States?
A) Bacteroides
B) Rickettsia
C) Chlamydia
D) Helicobacter
E) Treponema
25) Gram-negative bacteria in the genus ________ prey on other Gram-negative bacteria.
A) Bdellovibrio
B) Chlamydia
C) Rickettsia
D) Mycoplasma
E) Caulobacter
26) Unusual cellular extensions called prosthecae are associated with which of the following
groups of proteobacteria?
A) alphaproteobacteria
B) betaproteobacteria
C) gammaproteobacteria
D) deltaproteobacteria
E) epsilonproteobacteria
27) Which of the following bacterial genera plays an important role in environmental nitrogen
cycles?
A) Nitrobacter
B) Rhizobium
C) Azospirillum
D) both Nitrobacter and Rhizobium
E) Nitrobacter, Rhizobium, and Azospirillum
28) The ________ are obligately anaerobic bacilli found in human intestines that aid in
digestion of plant material.
A) methanogen
B) mycoplasma
C) bacteroides
D) clostridium
E) cyanobacterium
29) The classification of prokaryotes in Bergey’s Manual of Systematic Bacteriology is largely
based on
A) Gram stain reaction.
B) habitat.
C) type of electron receptor used in cellular respiration.
D) rRNA sequences.
E) cellular morphology.
30) Which of the following bacteria oxidize nitrite (NO2–) to produce nitrate (NO3–)?
A) Nitrobacter
B) Azospirillum
C) Nocardia
D) Cyanobacter
E) Rhizobium
31) The plant pathogen ________ is a member of the alphaproteobacteria that alters plant cells
by introducing DNA into them.
A) Azotobacter
B) Agrobacterium
C) Rhizobium
D) Pseudomonas
E) Bdellovibrio
32) Which of the following bacterial genera is useful for sewage treatment?
A) Burkholderia
B) Thiobacillus
C) Neisseria
D) Zoogloea
E) Nitrosomonas
33) A flexible, spiral-shaped bacterium is called a
A) spirochete.
B) vibrio.
C) coccobacillus.
D) spirillum.
E) sarcina.
34) Bacteria which move by means of gliding motility include
A) Cyanobacteria.
B) Cytophaga.
C) Clostridium.
D) Spirillum.
E) both Cyanobacteria and Cytophaga.
35) Which of the following statements regarding mycoplasmas is FALSE?
A) They are low G + C content bacteria.
B) They stain Gram positive.
C) They are pleomorphic.
D) They exhibit a “fried egg” appearance on solid media.
E) They are the smallest free-living cells.
36) The anaerobic Clostridium species are troublesome pathogens largely because of their
capacity for
A) endospore production.
B) rapid reproduction.
C) oxygen production.
D) biofilm production.
E) high salt tolerance.
37) The domain Archaea includes prokaryotes that are
A) endospore formers.
B) intracellular parasites.
C) members of the deeply branching bacteria.
D) human pathogens.
E) hyperthermophiles.
38) Which of the following is CORRECT about the prokaryotes known as deeply branching
bacteria?
A) They are chemoheterotrophs.
B) They lack peptidoglycan walls.
C) They are commonly found in acidic, anaerobic conditions.
D) They grow in long branching filaments.
E) They are photosynthetic.
39) Bacteria of the Proteobacteria that are intracellular parasites are members of the
A) alphaproteobacteria.
B) betaproteobacteria.
C) gammaproteobacteria
D) alphaproteobacteria and betaproteobactria.
E) alphaproteobacteria and gammaproteobacteria.
40) A Gram-positive psychrotrophic rod ________ is a frequent contaminant of dairy products
and meat and an opportunistic pathogen of the immunocompromised.
A) Escherichia coli
B) Helicobacter pylori
C) Clostridium perfringens
D) Bacillus thuringiensis
E) Listeria monocytogenes
41) A species of the genus Streptococcus is the leading cause of
A) tuberculosis.
B) urinary tract infections.
C) contaminated milk and meat.
D) “flesh-eating” bacterial infections.
E) food poisoning from rice.
42) The genus Mycobacterium includes species responsible for
A) tuberculosis.
B) urinary tract infections.
C) food poisoning from contaminated dairy products.
D) gastric ulcers.
E) food poisoning from rice.
43) Gram-negative nitrogen-fixing bacteria found in association with plant roots are
A) alphaproteobacteria.
B) betaproteobacteria.
C) cyanobacteria.
D) gammaproteobacteria.
E) deeply branching bacteria.
44) Members of the genus Chlamydia are
A) thermophiles.
B) intracellular parasites.
C) classified with the deeply branching bacteria.
D) endospore-formers.
E) Gram-positive bacteria.
45) Pseudomonas species are occasional causes of
A) diarrheal disease.
B) food poisoning from rice.
C) food poisoning from dairy products.
D) “flesh-eating” bacterial infections.
E) urinary tract infections.
11.2 True/False Questions
1) The majority of prokaryotes are capable of forming endospores.
2) When an endospore germinates, it gives rise to two daughter cells called vegetative cells.
3) Various species of Streptomyces are important sources of antibiotics.
4) Halophiles grow equally well in the presence or absence of high salt concentrations.
5) The purple sulfur bacteria carry out oxygenic photosynthesis.
6) Cocci can be spherical as well as kidney-shaped.
7) Some strains of Staphylococcus aureus can invade the body and cause diseases such as
pneumonia and bacteremia.
8) Mycoplasmas are named for the large quantities of mycolic acid in their cell walls.
9) Most of the methane produced by methanogens is oxidized by other types of bacteria before
it affects Earth’s climate.
10) Members of the zetaproteobacteria are autotrophs, some of which are iron oxidizers.
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11.3 Short Answer Questions
1) The process by which a bacterial cell produces an endospore is called
(endosporing/sporulation/vegetation).
2) The most common form of reproduction among prokaryotes is (budding/binary/snapping)
fission.
3) The rod-shaped (chlamydias/brucella/rickettsias) are intracellular parasitic members of the
alphaproteobacteria.
4) Some members of the alphaproteobacteria produce a structure called a
(filament/prostheca/pilus) to produce extra surface area for nutrient absorption.
5)
The bacterial shape in Figure 11.2 is called (bacillus/vibrio/rod).
6) The G + C content is a(n) (RNA/structural/genetic) determination used in classifying the
different taxa of Gram-positive bacteria.
7) The (streptobacilli/actinomycetes/mycoplasmas) are a group of Gram-positive bacteria that
form branching filaments resembling those of fungi.
8) The genus of pathogenic cocci responsible for a wide range of human disease and whose
members grow in chains is (Staphylococcus/Streptococcus/Enterococcus).
9) Gammaproteobacteria of the genus (Escherichia/Pseudomonas/Vibrio) catabolize
carbohydrates using pathways other than the standard glycolytic (Embden-Meyerhof) pathway.
10) The reduction of nitrogen gas to ammonia is called nitrogen (fixation/cycling/oxidation).
11) Slow-growing bacteria in the genus (Mycoplasma/Mycobacterium) are able to withstand
long exposure to air because of the presence of mycolic acid in their cell wall structure.
12) The bacterium (Agrobacterium/Cyanobacteria/Rhizobium) is a member of the
alphaproteobacteria that forms beneficial relationships with higher plants.
13) The (bacilli/Lactobacilli/bacteroids) are a group of Gram-negative bacteria that include
obligate anaerobes normally found in the intestinal tracts of animals and humans.
14) The infective stage of chlamydia is called the (elementary/endospore/initial) body.
15) Burkholderia is a common (true/opportunistic) pathogen of patients with cystic fibrosis.
11.4 Essay Questions
1) Will is a graduate student working in a microbiology lab. He is given the task of
characterizing a newly discovered nitrogen fixing bacterium. What type of tests or observations
will help him determine whether it is a member of the Cyanobacteria, alphaproteobacteria, or
gammaproteobacteria?
2) Compare and contrast methanogens and methane oxidizers, including their roles in the
environment.
3) Describe the major taxonomic divisions of prokaryotic organisms.
4) Describe the similarities and differences observed among phototrophic bacteria.
5) Explain the significance of endospores.