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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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.
Which of the following term means a collection of nutrients can support growth of microbe?
A. culture;
B. medium;
C. inoculum
D. specimen
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
Which special structure can be identified on Semisolid media?
A. Capsule
B. flagellum.
C. pili;
D. endospore