Questions and answers for exam Preparation

MCQs

Total Questions : 114 | Page 5 of 12 pages

Question 41. Saccharomyces cerevisiae when grown in high glucose concentration medium, the cells activity depends on which of the following?

High concentration of dissolved oxygen
Low concentration of dissolved oxygen
No effect of dissolved oxygen
High concentration of dissolved oxygen and sodium salts

Discuss Question

Answer: Option C. -> No effect of dissolved oxygen
Answer: (c).No effect of dissolved oxygen

Question 42. Continuous culture has an advantage over to a batch cultures as

continuous reactors do not need to be shut down and cleaned as regularly as a batch reactor
most downstream and upstream processes are continuous in nature and thus the operation of continuous bioreactor can be better integrated into the overall manufacturing process
cells can be maintained at a constant physiological state simply by setting the dilution rate
all of the above

Discuss Question

Answer: Option D. -> all of the above
Answer: (d).all of the above

Question 43. When Escherichia coli grow in a well aerated medium, which of the following will occur?

Fructose di-phosphate accumulation inside the cells leading to cell respiration
Fructose di-phosphate accumulation inside the cells leading to fermentation
Fructose di-phosphate will accumulate regardless of the medium composition
Fructose di-phosphate will accumulate inside the cells leading to anaerobic respiration

Discuss Question

Answer: Option B. -> Fructose di-phosphate accumulation inside the cells leading to fermentation
Answer: (b).Fructose di-phosphate accumulation inside the cells leading to fermentation

Question 44. Which of the following is best described as secondary metabolite?

Acetic acid produced from the oxidation of ethanol
Ethanol from the fermentation of glucose
Penicillin
Citric acid from the partial oxidation of glucose

Discuss Question

Answer: Option C. -> Penicillin
Answer: (c).Penicillin

Question 45. In the batch-fed mode, substrate will be added

only at the beginning of the fermentation process
periodically throughout the fermentation process
only at the end of the fermentation process
substrate is never added

Discuss Question

Answer: Option C. -> only at the end of the fermentation process
Answer: (c).only at the end of the fermentation process

Question 46. A microorganism which is subjected to the Crabtree effect is most likely to

ferment in the presence of low concentrations of sugar and dissolved oxygen
respire in the presence of low sugar and high dissolved oxygen concentrations
ferment in the presence of high concentrations of sugar and dissolved oxygen
respire in the presence of high sugar and low dissolved oxygen concentrations

Discuss Question

Answer: Option C. -> ferment in the presence of high concentrations of sugar and dissolved oxygen
Answer: (c).ferment in the presence of high concentrations of sugar and dissolved oxygen

Question 47. In a glucose-yeast extract medium, Lactococcus lactis has a maximum specific growth rate (um) of 1.23 h¹. What would be the specific growth rate of this organism at steady state in a 4 litre reactor being fed at 2 litres per hour?

0.5 h¹
1.2 h¹
2.4 h¹
4 h¹

Discuss Question

Answer: Option A. -> 0.5 h¹
Answer: (a).0.5 h¹

Question 48. Which of the following would be correct concerning the concentration of biomass (X). growth limiting substrate (S) and product (P) in a chemostat when the cells have been washed out?

X,S and P will be zero
X,S and P can not be predicted for the above condition
X and P will be zero while S is equal to the substrate concentration in feed
None of the above

Discuss Question

Answer: Option C. -> X and P will be zero while S is equal to the substrate concentration in feed
Answer: (c).X and P will be zero while S is equal to the substrate concentration in feed

Question 49. When the product formation is approximately equal to the rate of cell growth, the pattern of product formation is termed as

uncoupled
growth associated
non-growth associated
metabolically uncoupled

Discuss Question

Answer: Option B. -> growth associated
Answer: (b).growth associated

Question 50. Pseudomonas aeruginosa has a maximum specific growth rate of 0.8 h¹ in a medium with glucose as a growth limiting substrate. To prevent wash out, the dilution rate must be set to