MCQOPTIONS
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MCQOPTIONS
This section includes 128 Mcqs, each offering curated multiple-choice questions to sharpen your Biochemical knowledge and support exam preparation. Choose a topic below to get started.
| 51. |
The power required for agitation of non-aerated medium in fermentation is ________ kW. Operating conditions are as follows : Fermentor diameter = 3 m Number of impellers = 1Mixing speed = 300 rpm Diameter of the Rushton turbine = 1 m Viscosity of the broth = 0.001 Pa.s Density of the broth = 1000 kg.m 3 Power number = 5 |
| A. | 125 |
| B. | 225 |
| C. | 625 |
| D. | 729 |
| Answer» D. 729 | |
| 52. |
During cultivation of microorganisms in a fermenter, various parameters are controlled by appropriate sensor (probe). Match each probe in group 1 with the appropriate response mechanism in group 2. |
| A. | P-2, Q-3, R-1, S-4 |
| B. | P-l, Q-2, R-4, S-3 |
| C. | P-3, Q-2, R-4, S-1 |
| D. | P-3, Q-4, R-2, S-1 |
| Answer» E. | |
| 53. |
In a bioreactor baffles are incorporated to |
| A. | prevent vortex and to improve aeration efficiency |
| B. | maintain uniform suspension of cells |
| C. | minimize the size of air bubble for greater aeration |
| D. | maintain uniform nutrient medium |
| Answer» B. maintain uniform suspension of cells | |
| 54. |
Aeration in a biorector is provided by |
| A. | impeller |
| B. | baffles |
| C. | sparger |
| D. | all of these |
| Answer» D. all of these | |
| 55. |
The separation principle of dialysis used in the recovery of fermentation products is |
| A. | diffusion |
| B. | charge |
| C. | turbulence |
| D. | solubility |
| Answer» B. charge | |
| 56. |
What would be the dilution rate of the system at the end of second day? |
| A. | 2.00 |
| B. | 0.20 |
| C. | 0.02 |
| D. | 0.01 |
| Answer» C. 0.02 | |
| 57. |
What will be the overall productivity of the system in kg year |
| A. | 19250 |
| B. | 38.50 |
| C. | 3850 |
| D. | 77 |
| Answer» E. | |
| 58. |
Power number, also called Newton's number, is defined as a dimensionless parameter relating to |
| A. | turbulent flow |
| B. | the relative velocity between the nutrient solution and individual cells |
| C. | energy required by the stirred reactors |
| D. | none of the above |
| Answer» D. none of the above | |
| 59. |
What will be the annual output of the system (production of metabolite (X)) in kg per year ? |
| A. | 55 |
| B. | 3850 |
| C. | 45.5 |
| D. | 77 |
| Answer» C. 45.5 | |
| 60. |
Which one of the following monolayer culture systems have the highest surface area: medium ratio? |
| A. | Roux bottle |
| B. | Spiracell roller bottle |
| C. | Hollow fibres |
| D. | Plastic bag/film |
| Answer» D. Plastic bag/film | |
| 61. |
During the media preparation for cultivation of cells, insoluble precipitates of calcium phosphates are often formed. Identify which method can be adopted to avoid this problem? |
| A. | Hold the pH at 5.6 |
| B. | Hold the pH at 7.5 |
| C. | Add calcium salt first and then phosphate source |
| D. | None the above |
| Answer» E. | |
| 62. |
To optimize the bioreactor system, which one of the following conditions is least important for anaerobic fermentation ? |
| A. | culture agitation to maintain oxygen supply |
| B. | restriction of the entry of contaminating organisms |
| C. | control of parameters like pH and temperature |
| D. | maintenance of constant culture volume |
| Answer» B. restriction of the entry of contaminating organisms | |
| 63. |
A batch culture fermentation was being conducted with streptomyces rimosus. Analysis of samples collected indicated doubling of cell number per unit time. Youor inference would be that the culture is in the |
| A. | lag phase |
| B. | log phase |
| C. | stationary phase |
| D. | death phase |
| Answer» C. stationary phase | |
| 64. |
Identify the statement that is NOT correct |
| A. | Penicillin fermentation is an aerobic process |
| B. | Penicillin biosynthesis affected by phosphate concentration |
| C. | Lysine stimulates penicillin synthesis |
| D. | Penicillin production shows a distinct catabolite repression by glucose |
| Answer» D. Penicillin production shows a distinct catabolite repression by glucose | |
| 65. |
Which of the following statements applies to the operation of a fed-batch process ? |
| A. | The volume of the culture increases with time |
| B. | It helps controlling repressive effects of the nutrient being fed |
| C. | It eliminates the need for oxygen supply |
| D. | Only (a) and (b) of the above |
| Answer» E. | |
| 66. |
The limiting factor in the production of large quantities of ethanol as bio-fuel is |
| A. | Lack of a balanced medium |
| B. | Ethanol toxicity to cells |
| C. | Expensive downstream processing steps |
| D. | Only (b) and (c) of the above |
| Answer» E. | |
| 67. |
In large scale fermentation process, air is sterilized by |
| A. | Jute fiber |
| B. | Membrane |
| C. | Cotton fiber |
| D. | Glass wool fiber |
| Answer» E. | |
| 68. |
The precursor for penicillin-G biosynthesis during fermentation process is |
| A. | Phenylacetic acid |
| B. | Phenoxyacetic acid |
| C. | Acetic acid |
| D. | None of these |
| Answer» B. Phenoxyacetic acid | |
| 69. |
If the fractional recovery at each step of unit operation is 0.8, the recovery after 4 steps will be |
| A. | 0.24 |
| B. | 3.23 |
| C. | 0.41 |
| D. | 0.82 |
| Answer» D. 0.82 | |
| 70. |
The kinetics of the disintegration of baker s yeast cells in a bead mill is described as dp/dt = K. (P |
| A. | 10 hr |
| B. | 2 hr |
| C. | 4.6 hr |
| D. | None of these |
| Answer» D. None of these | |
| 71. |
The selection of the appropriate purification method in the product recovery after microbial fermentation depends on the |
| A. | nature and the stability of the end products produced |
| B. | type of the side products present |
| C. | degree of purification required |
| D. | all of these |
| Answer» E. | |
| 72. |
How many kilograms of ethanol is produced from 1 kilogram of glucose in ethanol fermentation? |
| A. | 2.00 |
| B. | 0.20 |
| C. | 0.51 |
| D. | 0.05 |
| Answer» D. 0.05 | |
| 73. |
Main functions of baffles in a bioreactor are |
| A. | P, Q |
| B. | Q, R |
| C. | R, S |
| D. | P, S |
| Answer» B. Q, R | |
| 74. |
Downstream processing of an industrial process yielded a highly purified bioactive protein. This protein was subjected to cleavage by trypsin. Chromatographic separation of products resulted in 4 peptides (P, Q, R, S) with the following amino acid sequences |
| A. | P, Q, R, S |
| B. | Q, P, R, S |
| C. | Q, R, P, S |
| D. | R, Q, P, S |
| Answer» D. R, Q, P, S | |
| 75. |
Write whether the following statements are true or false : |
| A. | Only a |
| B. | b and c |
| C. | Only b and e |
| D. | a , c , d and e |
| E. | None of these |
| Answer» F. | |
| 76. |
In secondary metabolism two distinct phases- trophophase and idiophase refer respectively to |
| A. | Growth and production phase |
| B. | Early and late phase |
| C. | Primary and secondary metabolism |
| D. | Lag phase and log phase |
| Answer» B. Early and late phase | |
| 77. |
Choose the correct completion of the following statement. |
| A. | it uses higher temperature for longer time |
| B. | it uses longer heating time during which heat is lost |
| C. | it uses larger volume and hence takes longer to cool the medium |
| D. | it uses steam as the heating source |
| Answer» C. it uses larger volume and hence takes longer to cool the medium | |
| 78. |
Which of the following is not true of aerobic digestion ? |
| A. | It generates most sludge |
| B. | It generally incurs higher running cost |
| C. | It may generate a usable fuel |
| D. | Requires a shorter residence time |
| Answer» D. Requires a shorter residence time | |
| 79. |
In large-scale fermentation, the preferred method of sterilization |
| A. | Chemicals |
| B. | Radiation |
| C. | Filtration |
| D. | Heat |
| Answer» E. | |
| 80. |
Oxygen transfer was measured in a stirred tank bioreactor using dynamic method. The dissolved oxygen tension was found to be 80% air saturation under steady state conditions. The measured oxygen tensions at 7s and 17s were 55% and 68% air saturation, respectively. The volumetric mass transfer coefficient K |
| A. | 7.339 |
| B. | 0.07339 |
| C. | 0.339 |
| D. | 7339 |
| Answer» C. 0.339 | |
| 81. |
The diameters of a large and a small vessel are 1.62 m and 16.2 cm, respectively. The vessels are geometrically similar and operated under similar volumetric agitated power input. The mixing time in the small vessel was found to be 15 s. Determine the mixing time (in seconds) in the large vessel. |
| A. | 15 |
| B. | 30 |
| C. | 61 |
| D. | 122 |
| Answer» D. 122 | |
| 82. |
A synchronous culture containing 1.8 10 |
| A. | 0 |
| B. | 1 |
| C. | 2 |
| D. | 3 |
| Answer» D. 3 | |
| 83. |
In a fed-batch culture, 200 g . L |
| A. | 40 |
| B. | 52 |
| C. | 60 |
| D. | 68 |
| Answer» C. 60 | |
| 84. |
Which of the following events occur during the stationary phase of bacterial growth? |
| A. | P, Q and S only |
| B. | P, S and T only |
| C. | Q, R and S only |
| D. | P, R and T only |
| Answer» B. P, S and T only | |
| 85. |
Which one of the following is the most suitable type of impeller for mixing high viscosity (viscosity > 10 |
| A. | Propeller |
| B. | Helical ribbon |
| C. | Paddle |
| D. | Flat blade turbine |
| Answer» C. Paddle | |
| 86. |
The power required for agitation of non-aerated medium in fermentation is ________ kW. |
| A. | 125 |
| B. | 225 |
| C. | 625 |
| D. | 729 |
| Answer» D. 729 | |
| 87. |
Fed batch cultivation is suitable for which of the following? |
| A. | P and Q only |
| B. | P and R only |
| C. | Q and R only |
| D. | P, Q and R |
| Answer» C. Q and R only | |
| 88. |
The unit for specific substrate consumption rate in a growing culture is |
| A. | <table><tr><td rowspan="2"></td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>g</center></td><td rowspan="2"> </td></tr><tr><td style="text-align: center;">L.h</td></tr></table> |
| B. | <table><tr><td rowspan="2"></td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>g</center></td><td rowspan="2"> </td></tr><tr><td style="text-align: center;">h</td></tr></table> |
| C. | <table><tr><td rowspan="2"></td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>g</center></td><td rowspan="2"> </td></tr><tr><td style="text-align: center;">g.h</td></tr></table> |
| D. | <table><tr><td rowspan="2"></td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>gmoles</center></td><td rowspan="2"> </td></tr><tr><td style="text-align: center;">L.h</td></tr></table> |
| Answer» D. <table><tr><td rowspan="2"></td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>gmoles</center></td><td rowspan="2"> </td></tr><tr><td style="text-align: center;">L.h</td></tr></table> | |
| 89. |
Biomass is being produced in a continuous stirred tank bioreactor of 750 L capacity. The sterile feed containing 8 g.L |
| A. | 0.85 |
| B. | 0.65 |
| C. | 0.45 |
| D. | 0.25 |
| Answer» C. 0.45 | |
| 90. |
Saccharomyces cerevisiae produces ethanol by fermentation. The theoretical yield of ethanol from 2.5 g of glucose is ______ g. |
| A. | 120 |
| B. | 12.0 |
| C. | 1.20 |
| D. | 0.120 |
| Answer» D. 0.120 | |
| 91. |
A bacterial culture having a specific oxygen uptake rate of 5 mmol O |
| A. | 14 g/l |
| B. | 26 g/l |
| C. | 32 g/l |
| D. | 65 g/l |
| Answer» E. | |
| 92. |
The maximum cell concentration (g l |
| A. | 36.7 to 46.9 |
| B. | 76.7 to 76.9 |
| C. | 86.7 to 96.9 |
| D. | None of the above |
| Answer» C. 86.7 to 96.9 | |
| 93. |
Samples of bacterial culture taken at 5 PM and then the next day at 5 AM were found to have 10 |
| A. | 1.2121 |
| B. | 12121 |
| C. | 12.121 |
| D. | 121.21 |
| Answer» B. 12121 | |
| 94. |
In a batch culture, the specific rate of substrate utilization is 0.25 g (g cell mass) |
| A. | 0.81 to 0.91 |
| B. | 0.27 to 0.31 |
| C. | 81 to 91 |
| D. | 0.91 to 0.98 |
| Answer» B. 0.27 to 0.31 | |
| 95. |
Calculate the percentage sequence identity for the pairwise alignment given below._____ |
| A. | 33.5 to 44.7 |
| B. | 66.5 to 66.7 |
| C. | 22.5 to 33.7 |
| D. | 99.5 to 99.7 |
| Answer» C. 22.5 to 33.7 | |
| 96. |
Match the bioreactor components in group 1 with the most appropriate function given in group 2 |
| A. | P-4 , Q-2 , R-1 , S-3 |
| B. | P-3 , Q-1 , R-4 , S-2 |
| C. | P-3 , Q-4 , R-2 , S-1 |
| D. | P-2 , Q-1 , R-4 , S-3 |
| Answer» C. P-3 , Q-4 , R-2 , S-1 | |
| 97. |
A batch bioreactor is to be scaled up from 10 to 10,000 liters. The diameter of the large bioreactor is 10 times that of the small bioreactor. The agitator speed in the small bioreactor is 450 rpm. Determine the agitator speed (rpm) of the large bioreactor with same impeller tip speed as that of the small bioreactor. ______ |
| A. | 45 |
| B. | 60 |
| C. | 75 |
| D. | 90 |
| Answer» B. 60 | |
| 98. |
A chemostat is operated at a dilution rate of 0.6 h |
| A. | 9 |
| B. | 38 |
| C. | 18 |
| D. | 58 |
| Answer» D. 58 | |
| 99. |
Match the downstream processes in Group I with the products in Group II. |
| A. | P-2 , Q-3 , R-1 , S-4 |
| B. | P-4 , Q-1 , R-2 , S-3 |
| C. | P-4 , Q-1 , R-3 , S-2 |
| D. | P-2 , Q-4 , R-1 , S-3 |
| Answer» B. P-4 , Q-1 , R-2 , S-3 | |
| 100. |
In an exponentially growing batch culture of Saccharomyces cerevisiae, the cell density is 20 gl |
| A. | 0.32 |
| B. | 0.64 |
| C. | 0.80 |
| D. | 0.50 |
| Answer» E. | |