49. In order to prove that a bacterium is pathological according to Koch’s postulates, all of the following
must be true, EXCEPT
a.
The bacteria must be present in every case of the disease
b.
The bacteria must be isolated from the infected host and grown in pure culture
c.
The specific disease must be induced when a pure culture of the bacteria is introduced into
a healthy host
d.
The bacteria must be isolated from the now experimentally infected host
e.
The bacterium must produce spores that can be transmitted from one individual to another
50. The evolutionary ancestors of mitochondria are believed to have been ancient
a.
Archaea.
b.
cyanobacteria.
c.
proteobacteria.
d.
green bacteria.
e.
Gram-positive bacteria.
51. In which of the following ways is proteobacterial photosynthesis different from plant photosynthesis?
a.
Proteobacterial photosynthesis uses a different type of chlorophyll.
b.
Proteobacterial photosynthesis does not produce oxygen.
c.
Proteobacterial photosynthesis uses water as an electron donor.
d.
Proteobacterial photosynthesis uses a different type of chlorophyll and does not produce
oxygen
e.
Proteobacterial photosynthesis occurs in the dark.
52. How is cyanobacterial photosynthesis similar to plant photosynthesis?
a.
in type of chlorophyll
b.
in splitting of water
c.
in production of oxygen
d.
in type of chlorophyll and in splitting water
e.
in type of chlorophyll, in splitting water, and in the production of oxygen
53. Which of the following statements describes proteobacteria?
a.
Gram-negative and includes the purple bacteria
b.
Gram-negative and includes the green bacteria
c.
Gram-positive and includes the purple bacteria
d.
Gram-positive and includes the green bacteria
e.
Gran-neutral and includes the green bacteria
54. Microbes that are found in hot springs or other extreme environments are most specifically likely to be
a.
Gram-negative.
b.
Gram-positive.
c.
archaeans.
d.
cyanobacteria.
e.
proteobacteria.
55. Archaea were first found
a.
to be pathogenic.
b.
living on the surface of leaves.
c.
in surface ocean water.
d.
in extreme environments.
e.
in benign environments.
56. Prokaryotes were split into two domains based on differences in
a.
staining characteristics.
b.
metabolic capabilities.
c.
rRNA sequences.
d.
cell membrane properties.
e.
cell wall composition.
57. Which of the following best describes the number of distinct evolutionary branches in the domain
Archaea, as revealed by genome sequencing studies?
a.
3−4
b.
6−7
c.
9−10
d.
at least 12
e.
at least 20
58. Where are the methanogens found?
a.
Crenarchaeota
b.
Euryarchaeota
c.
Korarchaeota
d.
Nanoarchaeota
e.
both Crenarchaeota and Euryarchaeota
59. Where would Methanococcus likely not be found?
a.
in anoxic environments
b.
in swamps
c.
in the intestines of a cow
d.
in anaerobic environments
e.
in aerobic environments
60. Archaea that have been cultured in the laboratory include
a.
Crenarchaeota and Euryarchaeota.
b.
Crenarchaeota and Korarchaeota.
c.
Euryarchaeota and Korarchaeota.
d.
Euryarchaeota and Nanorarchaeota.
e.
Nanoarchaeota and Korarchaeota.
61. Which of the following statements about Korarchaeota is true?
a.
includes halophiles
b.
includes thermophiles
c.
oldest known lineage in the Archaea
d.
includes halophiles and thermophiles
e.
most recently discovered lineage in the Archaea
62. The presence of a nuclear membrane is
a.
characteristic of Archaea only
b.
characteristic of Bacteria only
c.
characteristic of both Archaea and Bacteria
d.
characteristic of neither Archaea nor Bacteria
e.
characteristic of both Archaea, Bacteria and Eukarya
63. Which of the following are potentially pathogenic to humans?
a.
Archaea
b.
Bacteria
c.
Archaea and Bacteria
d.
Cyanobacteria
e.
Methanogens
64. For which of the following is the first amino acid in proteins formylmethionine?
a.
Archaea only
b.
Bacteria only
c.
both Archaea and Bacteria
d.
neither Archaea nor Bacteria
e.
Archaea, Bacteria and Eukarya
65. The presence of cytoplasmic organelles is characteristic of
a.
Archaea only.
b.
Bacteria only.
c.
both Archaea and Bacteria.
d.
neither Archaea nor Bacteria.
e.
Achaea, Bacteria and Eukarya.
66. Which of the following stain as either Gram-positive or Gram-negative?
a.
Archaea
b.
Bacteria
c.
Archaea and Bacteria
d.
neither Archaea nor Bacteria
e.
Methanogens
67. Which of the following have flagella?
a.
Archaea
b.
Bacteria
c.
Archaea and Bacteria
d.
neither Archaea nor Bacteria
e.
only cyanobacteria
68. The presence of branched membrane lipids, with ether linkages is a characteristic of
a.
Archaea only.
b.
Bacteria only.
c.
both Archaea and Bacteria.
d.
of neither Archaea nor Bacteria.
e.
Archea, Bacteria and Eukarya.
69. Which of the following have a single, circular chromosome?
a.
Archaea
b.
Bacteria
c.
both Archaea and Bacteria
d.
neither Archaea nor Bacteria
e.
only methanogens
70. Archaeans like Sulfolobus have multiple origins of replication. This suggests that they
a.
in this regard, are more like bacteria than eukaryotes.
b.
in this regard, are more like eukaryotes than bacteria.
c.
have a unique form of chromosomal replication.
d.
have multiple plasmids, whose replication must be coordinated.
e.
have multiple chromosomes.
Select the Exception
71. Which of the following is NOT a Gram-positive bacterium?
a.
Clostridium
b.
Staphylococcus
c.
Streptococcus
d.
Salmonella
e.
Lactobacillus
72. Which of the following statements about the botulism toxin is NOT true?
a.
It is an exotoxin.
b.
It is produced by the bacterium Clostridium.
c.
It may be found as a contaminant in poorly prepared food.
d.
Its brand name is Botox.
e.
It causes muscles to contract.
73. All of the following statements about mycoplasmas are true EXCEPT
a.
they possess a nucleoid.
b.
they lack a cell wall.
c.
they are Bacteria.
d.
they are Archaea.
e.
they are resistant to penicillin.
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74. Which of the following is NOT photoautotrophic?
a.
Cyanobacteria
b.
Green sulfur bacteria
c.
purple sulfur bacteria
d.
purple non-sulfur bacteria
e.
Cyanobacteria and purple sulfur bacteria
MATCHING
Match each prokaryotic genus with its correct description.
a.
Causes anthrax
b.
Fixes nitrogen
c.
Causes syphilis
d.
Thrives in very high temperatures
e.
Causes typhoid fever
f.
Aids in the production of yoghurt
g.
Causes necrotizing fasciitis (flesh-eating disease)
h.
Thrives in very high salt concentrations
i.
Causes gonorrhea
j.
Produces CH4
k.
Causes trachoma (a preventable form of blindness)
l.
Releases oxygen as a byproduct
75. Azotobacter
76. Bacillus
77. Chlamydia
78. Halobacterium
79. Lactobacillus
80. Methanococcus
81. Neisseria
82. Pyrobolus
83. Cyanobacteria
84. Streptococcus
85. Treponema
86. Salmonella
MODIFIED TRUE/FALSE
If the statement is true, answer “T“. If the statement is false, answer “F” and make it correct by
changing the underlined word(s) and writing the correct word(s) in the answer blank(s).
87. Transformation involves contact between two bacterial cells, followed by the unidirectional transfer of
plasmid genes.
88. A slime coat called peptidoglycan covers the walls of many bacteria.
89. The flagella of bacteria rotate at their bases like propellers.
90. Chlamydias are bacteria that possess cell walls, but lack peptidoglycan.
91. A lichen is sometimes a symbiotic association between a proteobacterium and a fungus.
92. Organisms that live optimally in cold temperatures are called barophiles.
93. Spirilli are Gram-negative bacteria that possess internal flagella, which cause the entire cell to twist in
a corkscrew pattern.
94. Extracellular polymer substance (EPS) is a slimy, glue-like substance produced by bacteria to facilitate
the formation of endospores.
95. Archaea have multiple types of RNA polymerase.
96. Genome sequence comparisons have now shown that the Korarchaeota are most likely a subgroup of
the Euryarchaeota.
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ESSAY
97. Discuss why Gram-positive and Gram-negative bacteria stain differently with the Gram stain? How is
this difference reflected in antibiotic sensitivity/resistance?
98. List and discuss five structures in bacteria that allow them to cause disease.
ANS:
SHORT ANSWER
99. What are the primary evolutionary mechanisms that result in the great diversity and adaptation in
prokaryotes?
100. Why are archaeans more tolerant of extreme environmental conditions than bacteria?
101. Differentiate between endotoxins and exoenzymes.
102. Why is it problematic to take antibiotics for viral diseases?
103. What characteristics clearly separate Eukarya from Bacteria, but not Eukarya from Archaea?