1. The function of the disengagement zone in an airlift fermenter is to
A.prevent CO2 rich bubbles from entering the downcomer
B.reduce the velocity of the bubbles
C.reduce liquid loss as aerosols
D.all of the above

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2. Stationary phase is described as
A.no further increase in the cell population after a maximum value
B.deceleration of growth and division rate after the growth rate reaches a maximum
C.acceleration of growth and division rate after the growth rate reaches a maximum
D.deceleration of growth and division rate after the growth rate reaches a minimum

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3. In the accelerated phase, cell starts to
A.increase and the division rate increases to reach a maximum
B.decrease and the division rate increases to reach a maximum
C.increase and the division rate decreases to reach a maximum
D.increase and the division rate increases to reach a minimum

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4. The monod model predicts that the specific growth rate
A.will increase with the concentration of the growth limiting substrate until it reaches a maximum value
B.will decrease with the concentration of the growth limiting substrate
C.will increase with the concentration of the growth limiting substrate
D.does not depend on growth limiting substrate

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5. A mixed fermentation is one, which produces
A.both alcohol and carbon dioxide
B.both acid and carbon dioxide
C.both acid and alcohol
D.several different kinds of acid

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6. The function of a mechanical seal is to
A.prevent contaminants entering the reactor
B.prevent cells from leaving the reactor
C.both (a) and (b)
D.prevent air to enter

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7. The phenomenon in which substrates are used in a sequential manner is known as
A.trans-substrate genesis
B.dialism
C.diauxie
D.multiplicity

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