超星 - Quiz of lecture 10

单选题

Which bacterial enzyme of following ones is not associated with invasion?

A. Hyaluronidase;
B. beta-lactamases
C. IgA proteinase
D. staphylokinase

单选题

The nature of bacterial capsules is to __________________.

A. cause widespread blood clotting;
B. allow phagocytes to engulf these bacteria;
C. affect the virulence of these bacteria;
D. have no effect on the virulence of bacteria

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单选题

Which one of the following pathogens are most likely to cause severe infectious disease?

A. opportunistic pathogens in a weakened host;
B. pathogens lacking the enzyme kinase;
C. pathogens lacking the enzyme collagenase;
D. highly virulent microorganisms

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单选题

Which is not the condition for the opportunist to cause diseases?

A. Phagocytes activated by Lipid A.
B. Immune cells are killed by chemotherapy against tumor;
C. long term and large doses antibiotics taken;
D. Change of inhabiting sites;

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单选题

In which type of symbiosis does one member get benefit from itshost, causing harm to another member. ?

A. Mutualism
B. parasitism
C. commensalism
D. all above.

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单选题

Which of the following is false concerning microbial contaminants?

A. Contaminants may become opportunistic pathogens.
B. Most microbial contaminants will eventually cause harm.
Contaminants may be a part of the transient microbiota.
D. Contaminants may be introduced by a mosquito bite.

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单选题

The process by which microorganisms attach themselves to hostcells is _____________.

A. Infection
B. contamination
C. disease
D. adhesion

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单选题

In which type of symbiosis do both members benefit from theirinteraction?

A. Mutualism
B. parasitism
C. commensalism
D. all above.

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多选题

When pathogenic bacteria lose the ability to make adhesins owing to insertion of Tn5 into the gene of pili, they typically ________________.

A. become avirulent
B. produce modified enzyme to break kanamycine
C. Produce endotoxin
D. decrease in virulence

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多选题

Which statement about normal flora are right __________.

A. Inhibit R plasmid spread among different bacteria species.
B. Activate immune cells;
C. Antagonism against foreign bacteria;
D. Provide Vit.K to the host;

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