Explore topic-wise MCQs in Biotechnology.

This section includes 86 Mcqs, each offering curated multiple-choice questions to sharpen your Biotechnology knowledge and support exam preparation. Choose a topic below to get started.

51.

Sugar content of the fermentation medium for citric acid is maintained at

A. 10-15%
B. 15-20%
C. 20-25 %
D. 25-30 %
Answer» D. 25-30 %
52.

What are the fermentation conditions for the ethanol production?

A. pH 6; temperature 35°C
B. pH 5; temperature 35°C
C. pH 6; temperature 30°C
D. pH 5; temperature 30°C
Answer» C. pH 6; temperature 30°C
53.

Sodium or potassium meta bi sulphate is added to crushed grapes to

A. enhance the flavouring compound
B. check the undesirable organisms
C. maintain pH
D. all of the above
Answer» C. maintain pH
54.

The crystal-like material sometimes found in wine bottles is

A. residual diatomaceous earth
B. tannin
C. prevented by cold stabilizing
D. caused by excessive malic acid
Answer» D. caused by excessive malic acid
55.

Sake is

A. rice beer or wine of India
B. wheat beer or wine
C. barley beer or wine
D. rice beer or wine of Japan
Answer» E.
56.

The germination of barley kernels under controlled temperature and humidity to generate enzymes for the degradation of starch and protein is known as

A. brewing
B. malting
C. mashing
D. pitching
Answer» C. mashing
57.

The organism used for the preparation of sonti is

A. Rhizopus sonti
B. Aspergillus oryzae
C. Lactobacillus vermiformis
D. Saccharomyces pyriformis
Answer» B. Aspergillus oryzae
58.

Grist is

A. coarse powder obtained after milling of malted barley
B. an aqueous extract of malt
C. malted barley
D. coagulated protein obtained during boiling
Answer» B. an aqueous extract of malt
59.

The fermentor can be sterilized by

A. keeping it in the oven
B. steam under pressure
C. boiling
D. all of these
Answer» C. boiling
60.

The organism used for the preparation of sake is

A. Rhizopus sonti
B. Aspergillus oryzae
C. Lactobacillus vermiformis
D. Saccharomyces pyriformis
Answer» C. Lactobacillus vermiformis
61.

Sherry is a type of

A. wine
B. beer
C. brandy
D. none of these
Answer» B. beer
62.

The dried malt is the source of

A. amylase
B. proteinases
C. both (a) and (b)
D. cellulase
Answer» D. cellulase
63.

Sonti is

A. rice beer or wine of India
B. wheat beer or wine
C. barley beer or wine
D. rice beer or wine of Japan
Answer» B. wheat beer or wine
64.

The process of making malt as soluble as possible by using enzymes adjuncts etc is known as

A. brewing
B. malting
C. mashing
D. pitching
Answer» D. pitching
65.

After the fermentation is over, ethanol is recovered by

A. centrifugation
B. distillation
C. filtration
D. cell disintegration
Answer» C. filtration
66.

Which of the following organism is used for the fermentation of grapes?

A. Rhizopus sonti
B. Aspergillus oryzae
C. Lactobacillus vermiformis
D. Saccharomyces cerevisiae
Answer» E.
67.

In liquid surface culture process for the fermentation to produce citric acid,

A. A. niger is used with solid substrate as sweet potato
B. A. niger floats on the surface of solution
C. Fungal mycelium grows through out the solution in a deep tank
D. both (a) and (b)
Answer» C. Fungal mycelium grows through out the solution in a deep tank
68.

What temperature is maintained during anaerobic fermentation of white wine?

A. 10-21 °C
B. 21-30 °C
C. 30-35 °C
D. 15-25 °C
Answer» B. 21-30 °C
69.

Ethanol is oxidized to acetic acid aerobically using

A. Acetobacter
B. Gluconobacter
C. both (a) and (b)
D. Lactobacillus
Answer» D. Lactobacillus
70.

What is the pH of the medium when molasses is used as substrate for the production of citric acid?

A. 3
B. 4
C. 5
D. 6
Answer» D. 6
71.

For the recovery of citric acid after fermentation, Ca(OH)2 is added to the slurry to

A. precipitate calcium carbonate
B. precipitate calcium citrate
C. precipitate calcium phosphate
D. precipitate calcium sulphate
Answer» C. precipitate calcium phosphate
72.

What temperature is maintained during anaerobic fermentation of red wine?

A. 20-24 °C
B. 24-27 °C
C. 27-31 °C
D. 31-34 °C
Answer» C. 27-31 °C
73.

Which of the following is used for aeration in a fermentor?

A. Impeller
B. Baffles
C. Sparger
D. All of these
Answer» D. All of these
74.

Vinegar is typically produced in fed batch reactors because

A. a fed batch reactor can be used to maintain low acetic acid concentrations
B. a fed batch reactor can be used to maintain low ethanol concentrations
C. acetic acid bacteria tend to ferment at high ethanol concentrations
D. all of the above
Answer» C. acetic acid bacteria tend to ferment at high ethanol concentrations
75.

Malolactic fermentation

A. produces lactic acid
B. reduces total acidity
C. produces diacetyl
D. all of these
Answer» E.
76.

Which is not the purpose of punching down?

A. To oxidize the wine
B. To extract tannin
C. To reduce possible microbial spoilage
D. To keep the cap moist
Answer» B. To extract tannin
77.

Candida utilis is used for the fermentation of waste sulphate liquor since it ferments

A. hexoses only
B. pentoses only
C. both hexoses and pentoses
D. none of these
Answer» D. none of these
78.

Which type of press produces the most high quality juice or wine?

A. Membrane press
B. Continuous press
C. Vertical basket press
D. Horizontal basket press
Answer» B. Continuous press
79.

Wine yeast

A. is sensitive to sulphur di oxide
B. is resistant to sulphur di oxide
C. shows enhanced enzyme production in presence of sulphur di oxide
D. none of the above
Answer» C. shows enhanced enzyme production in presence of sulphur di oxide
80.

What are different substrates used for ethanol production?

A. Starch containing substrate
B. Juices from sugarcane or molasses or sugar beet
C. Waste product from wood or processed wood
D. All of the above
Answer» E.
81.

Maturation of the beers is carried out at

A. 14°C
B. 10°C
C. 6°C
D. 2°C
Answer» E.
82.

The yeast generated during the fermentation of beer is generally separated by

A. centrifugation
B. filtration
C. cell disruption
D. all of these
Answer» B. filtration
83.

Final alcohol content in wine varies from

A. 6-9 % by weight
B. 8-13 % by weight
C. both (a) and (b)
D. 13-15 % by weight
Answer» D. 13-15 % by weight
84.

What is the desirable sugar content of the grapes required for the wine production?

A. 2-5%
B. 5-10%
C. 10-14%
D. 14-20%
Answer» E.
85.

Bock beer is prepared from

A. roasted germinated barley seeds
B. rice
C. wheat
D. grapes
Answer» B. rice
86.

Which of the following is true for the ale beer?

A. Top yeast of S cerevisiae is used
B. Fermentation is quick and completes in 5-7 days
C. Quantity of hops used is more than in lager beer
D. All of the above
Answer» E.