11. Lag phase occurs mainly due to

A. acclimatization with new environment and substrate
B. higher growth temperature
C. substrate disliking
D. variation in substrate concentration

12. In a batch reactor specific growth rate

A. remains constant throughout the process
B. increases exponentially
C. changes during the fermentation
D. is highest during the stationary phase

13. Turbidostat is recommended when continuous fermentation needs to be carried out at

A. high dilution rates near the washout point
B. low dilution rates near the washout point
C. moderate dilution rates near the washout point
D. any intensity of dilution rates near the washout point

14. The advantage of airlift bioreactors over stirred tank bioreactors of a similar size is

A. higher oxygen transfer rates
B. more uniform shear conditions
C. both (a) and (b)
D. less foaming

15. Stirred tank fermenter (STF) can be employed for

A. aerobic fermentation of a wide range of cells including microbial, animal, and plant cells
B. anaerobic fermentation of a wide range of cells including microbial, animal, and plant cells
C. Both (a) and (b)
D. anaerobic fermentation of plant cells only