超星 - Quiz of lecture 4

单选题

Which four phases happen in right order in the bacterial growth curve?

A. logarithmic, stationary, death phase, lag.
B. lag; logarithmic, stationary, death phase.
C. stationary, lag, logarithmic, death phase.
D. lag, stationary, logarithmic, death phase.

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单选题

In which phase are the endospores produced by some bacteria?

A. lag,
B. stationary,
C. logarithmic,
D. death phase.

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单选题

Which of the following is not the cause of cell death at death phase?

A. production of antibiotics;
B. toxic metabolites accumulation.
C. autolytic enzymes;
D. the nutrients exhaustion;

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单选题

Which statement is not right at log phase?

A. The growth of 2n;
B. DNA and protein syntheses are maximized.
C. The growth rate reaches a constant;
D. No toxic metabolites produced.

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单选题

Which of the following term means a collection of nutrients can support growth of microbe?

A. culture;
B. medium;
C. inoculum
D. specimen

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单选题

Petri plate is made by adding _____ into nutrient broth, dissolving it at 100℃ and poured into Petri dishes to solidify at 40 ℃ .

A. 0.5% agar;
B. 4% agar;
C. 2% agar
D. 0.1% agar

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单选题

Which special structure can be identified on Semisolid media?

A. Capsule
B. flagellum.
C. pili;
D. endospore

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单选题

Which statement about colony is not right?

Almost all organisms within the colony are genetically identical
B. One colony is grown by several bacterial cells;
C. One colony is grown by only one bacterial cell;
D. Solid medium is used to support growth of colony.

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单选题

A pure culture is usually obtained by transferring ____into a tube of new, sterile broth for further cultivation.

A. one bacterial colony on the agar plate;
B. Two different bacterial colonies on the agar plate;
C. Two same bacterialcolonies on the agar plate;
D. several colonies on the agar plate;

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多选题

What metabolites of bacteria could be harmful to human being?

A. toxins;
B. antibiotics:
C. Pyrogen;
D. invasive enzymes;

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