Lipid A is a cell wall component of:
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2%
Teichoic acid
1%
Viruses
0%
Fungi
97%
Gram negative bacteria
One of the following is a function of the cell wall:
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85%
Maintaining the characteristic shape of the bacterial cell
7%
Selective transport
4%
Respiration, since respiratory enzymatic located in it
3%
Excretion of extracellular enzymes
The following are functions of the bacterial cell wall EXCEPT:
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3%
It provides shape and rigidity
86%
Active transport of nutrients
7%
It protects from environmental factors
3%
Responsible for the staining property
The bacterial structure responsible for the reaction to Gram stain is:
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9%
The cytoplasmic membrane
89%
The cell wall
0%
The fimbriae
2%
The capsule
0%
The inclusion granules
What is the major chemical component giving bacterial cells protection from osmotic damage?
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13%
Lipopolysaccharide
72%
Peptidoglycan
10%
Phospholipids
5%
Polysaccharide
All the following are characters of L-forms of bacteria EXCEPT:
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73%
They are naturally occurring without cell wall
12%
They are resistant to antibiotics which inhibit cell wall synthesis
2%
They develop only in isotopic media
12%
They may resynthesize the cell wall
Mycoplasmas are intrinsically resistant to penicillin because they lack
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99%
Cell wall
1%
Cytoplasmic membrane
0%
Plasmids
0%
Ribosomes
Bacterial capsule is most commonly composed of:
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5%
Polypeptides
73%
Polysaccharides
3%
Lipids
19%
Peptidoglycan
All the following about the bacterial capsule is true EXCEPT:
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3%
Usually polysaccharide in nature
0%
Acts to prevent phagocytosis
79%
Plays a role in bacterial division
18%
May show and determine serotypes
Bacterial capsules have the following characters EXCEPT:
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3%
They are important virulence factors
55%
They are lipopolysaccharides in nature
34%
They are formed only inside the host (in vivo)
8%
They protect the cell wall against various kinds of antibacterial agents
Bacteria are protected from phagocytosis by:
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92%
The capsule
0%
The mesosome
1%
The outer membrane
3%
The cell wall
4%
The endospores
The structure which protects bacteria from bacteriophages is:
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3%
The pill
87%
The capsule
8%
The cell wall
3%
The flagella
Which of the following structures may be used for attachment of bacterial cells to surfaces and to other cells?
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15%
Fimbriae
0%
Cell wall
9%
Glycocalyx
6%
Both a and b
69%
Both a and c
Each of the following statements is correct EXCEPT:
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3%
Pili help attachment of bacteria to mucosal epithelium
14%
Both Gram negative bacilli and cocci have lipopolysaccharide (endotoxin) in their cell wall
74%
Bacterial flagella are non-antigenic in humans
9%
The sex pilus is involved in transfer of DNA between bacteria
All of the flowing are true concerning pili EXCEPT:
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3%
They mediate bacterial adherence
9%
They may be involved in bacterial conjugation
70%
Their antigen is called H antigen
17%
They are important virulence factors
Each of the following statements concerning bacterial spores is correct EXCEPT:
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11%
Spores are resistant to boiling
75%
The bacterial chromosome is not included in the spore
5%
Spores are metabolically inactive
10%
The spores coats contain dipicolinic acid
The marked resistance of the spores can be attributed to all the following factors EXCEPT
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5%
The impermeability of their cortex and outer coat
64%
Their ability to resist phagocytosis
10%
Their very low metabolic and enzymatic activity
21%
Their high content of Ca and dipicolinic acid
Which structure is responsible for bacterial motility
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6%
Fimbria
94%
Flagellum
0%
Glycocalyx
0%
Mesosome
Which of the following statements about prokaryotes is TRUE?
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2%
They contain membrane-bound organelles.
8%
Their DNA is enclosed within a nuclear membrane
81%
They contain a 70S ribosome
5%
They have sterols in their cell membrane like eukaryotes
5%
Their DNA is organized into chromosomes