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Microbiology Concepts
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Microbiology Concepts
Microbiology Concepts
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1
Question
Which one of the following terms characterizes the interaction between a fungus and algae in a lichen?
Answer
B Symbiosis
2
Question
Which one of the following agents lacks nucleic acid?
Answer
D Prions
3
Question
Which one of the following is not a protist?
Answer
A Bacteria
4
Question
Which one of the following agents simultaneously contains both DNA and RNA?
Answer
A Bacteria
5
Question
This disease is caused by which of the following agents? A 65-year-old man develops dementia, progressive over several months, along with ataxia and somnolence. An electroencephalographic pattern shows paroxysms with high voltages and slow waves, suggestive of Creutzfeldt-Jakob disease.
Answer
D Prion
6
Question
Which of the following cannot be infected by viruses?
Answer
E None of the above
7
Question
Viruses, bacteria, and protists are uniquely characterized by their respective size. True or false?
Answer
B False
8
Question
Which of the following are prokaryotes?
Answer
A Archaebacteria
9
Question
Quorum sensing in prokaryotes involves
Answer
E All of the above
10
Question
Twenty minutes after ingesting a raw clam, a 35-year-old man experiences paresthesias of the mouth and extremities, headache, and ataxia. These symptoms are the result of a neurotoxin produced by algae called
Answer
C Dinoflagellates
11
Question
Treponema pallidum, the causative agent of syphilis, cannot be visualized by light microscopy because
Answer
B It cannot be stained by ordinary stains.
12
Question
Chloramphenicol, an antibiotic that inhibits bacterial protein synthesis, will also affect which of the following eukaryotic organelles?
Answer
A Mitochondria
13
Question
Which of the following structures is not part of the bacterial cell envelope?
Answer
D Gas vacuole
14
Question
Which of the following transport mechanisms functions without the requirement for energy?
Answer
E Facilitated diffusion
15
Question
Which of the following components is present in gram-negative bacteria but not in gram-positive bacteria?
Answer
B Lipid A
16
Question
Which of the following components is present in gram-positive bacteria but not in gram-negative bacteria?
Answer
D Teichoic acid
17
Question
The heat resistance of bacterial spores, such as those of Bacillus anthracis, is partly attributable to their dehydrated state and partly to the presence of large amounts of
Answer
C Calcium dipicolinate
18
Question
Which of the following terms does NOT describe the bacterial chromosome?
Answer
B Diploid
19
Question
Lysozyme cleaves the 14 linkage between
Answer
D N-Acetylmuramic acid and N-acetylglucosamine.
20
Question
Mycoplasma species lack which of the following components?
Answer
E Peptidoglycan
21
Question
Eubacteria that lack cell walls and do not synthesize the precursors of peptidoglycan are called
Answer
C Mycoplasmas
22
Question
Archaebacteria can be distinguished from eubacteria by their lack of
Answer
D Peptidoglycan.
23
Question
During a nosocomial outbreak of B. cepacia, which of the following techniques would be most useful in identifying the source of the outbreak?
Answer
C 16S rRNA sequencing
24
Question
An unculturable gram-positive microorganism has been visualized in tissue specimens obtained from patients with a previously undescribed disease. Which of the following techniques would be most useful in identifying this organism?
Answer
B PCR amplification and sequencing of rRNA genes.
25
Question
The DNA polymerase from Thermus aquaticus is an important component of DNA amplification methods such as the polymerase chain reaction. This organism is capable of growing at temperatures above 100C. Organisms that are capable of growth at these temperatures are referred to as
Answer
D Thermophiles.
26
Question
These E. coli have a generation time of 20 minutes. After a lag of 20 minutes, the E. coli enter the logarithmic phase of growth. After 3 hours of logarithmic growth, the total number of cells is
Answer
A 2560.
27
Question
After 10 minutes, 90 of the cells are killed. How many cells remain viable after 20 minutes?
Answer
B 100.
28
Question
The action of which of the following agents or processes on bacteria can be reversed?
Answer
C A bacteriostatic agent.
29
Question
The growth rate of bacteria during the exponential phase of growth is
Answer
B Increasing.
30
Question
The growth rate of bacteria during the maximum stationary phase of growth is
Answer
A Zero.