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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.
1. |
The spoilage most commonly occurring in wine is tourne which refers to |
A. | acid formation from aldehyde and ketones |
B. | acid formation from sugars, glucose and fructose |
C. | both (a) and (b) |
D. | none of the above |
Answer» C. both (a) and (b) | |
2. |
If starch containing substrates are used for ethanol production, yeast strain can't be used directly because |
A. | it doesn't contain amylases to hydrolyze starch |
B. | starch is not a suitable substrate for the production of ethanol |
C. | it is converted to pentose sugar |
D. | none of the above |
Answer» B. starch is not a suitable substrate for the production of ethanol | |
3. |
S cerevisiae start producing ethanol with in |
A. | 10 h |
B. | 12 h |
C. | 15 h |
D. | 24 h |
Answer» C. 15 h | |
4. |
Which of the following is used to check vortex and to improve aeration efficiency in a fermentor? |
A. | Impeller |
B. | Baffles |
C. | Sparger |
D. | All of these |
Answer» C. Sparger | |
5. |
How is air supply to the fermentor sterilized? |
A. | By heat filtration |
B. | Filtration through fibrous material |
C. | Filtration through granular material |
D. | All of the above |
Answer» E. | |
6. |
The Zygomonas has a merit over yeast because |
A. | it has more osmotic tolerance to higher sugar concentration |
B. | it has high tolerance to ethanol |
C. | it has more specific growth rate |
D. | all of the above |
Answer» E. | |
7. |
Which substrate is used in the fermentation of citric acid? |
A. | Beet molasses |
B. | Sucrose |
C. | Starch hydrolysate |
D. | All of these |
Answer» E. | |
8. |
Which of the following microorganisms help in the ethanol production? |
A. | Saccharomyces cerevisiae |
B. | Zygomonas mobilis |
C. | Saccharomyces uvarum |
D. | All of these |
Answer» E. | |
9. |
To maintain aseptic conditions during fermentation which of the following is needed? |
A. | Sterilization of fermentor |
B. | Sterilization of air supply |
C. | Aeration and agitation |
D. | All of these |
Answer» E. | |
10. |
Which of the following nitrogen sources is added in the fermentation medium of citric acid production? |
A. | Ammonium salt |
B. | Urea |
C. | Both (a) and (b) |
D. | Peptone |
Answer» D. Peptone | |
11. |
Malt vinegar is produced from |
A. | fruit juices |
B. | malted grain |
C. | ethanol |
D. | ale |
Answer» C. ethanol | |
12. |
Vinegar production consists of |
A. | aerobic fermentation |
B. | anaerobic fermentation |
C. | aerobic fermentation followed by anaerobic fermentation |
D. | anaerobic fermentation followed by aerobic fermentation |
Answer» E. | |
13. |
The crushed grapes are known as |
A. | malt |
B. | must |
C. | wort |
D. | sonti |
Answer» C. wort | |
14. |
If a winemaker wanted to make a deeply colored red wine, which of the following should not be done? |
A. | Bleed off juice prior to fermenting on skins |
B. | Ferment at a high temperature |
C. | Use whole clusters |
D. | Punch down at least once a day |
Answer» D. Punch down at least once a day | |
15. |
Alcohol content of sake varies from |
A. | 1-5 % |
B. | 4-17 % |
C. | 17-25% |
D. | more than 25% |
Answer» C. 17-25% | |
16. |
If the malolactic fermentation is not carried out, |
A. | the wine will have an odd odor |
B. | malic acid may precipitate, leaving small crystals |
C. | the wine may be microbially unstable |
D. | the wine will be too low in acid |
Answer» D. the wine will be too low in acid | |
17. |
Wine is obtained after alcoholic fermentation of |
A. | rice |
B. | wheat |
C. | grapes |
D. | barley |
Answer» D. barley | |
18. |
In a hot climate, grapes lose acidity because |
A. | enough tartaric acid is not made |
B. | enough malic acid is not made |
C. | of break down of malic acid |
D. | of break down of tartaric acid |
Answer» D. of break down of tartaric acid | |
19. |
How long does it take to complete fermentation process in case of white wine? |
A. | 1-3 days |
B. | 3-5 days |
C. | 5-7 days |
D. | 7-11 days |
Answer» E. | |
20. |
Fining a wine is defined as |
A. | adding one substance to remove another |
B. | removing small particles |
C. | adding acid |
D. | removing tannin |
Answer» B. removing small particles | |
21. |
Which of the following is true for the lager beer? |
A. | Bottom fermenting yeast is used for the preparation |
B. | Top yeast is used for the preparation |
C. | Require high fermentation temperature |
D. | Both (b) and (c) |
Answer» B. Top yeast is used for the preparation | |
22. |
Wort is |
A. | an aqueous extract of malt |
B. | malted barley |
C. | coagulated protein obtained during boiling |
D. | none of the above |
Answer» B. malted barley | |
23. |
How long does it take to complete fermentation process in case of red wine? |
A. | 1-3 days |
B. | 3-5 days |
C. | 5-7 days |
D. | 7-11 days |
Answer» C. 5-7 days | |
24. |
Which of the following microorganism is used for the production of citric acid? |
A. | Lactobacillus bulgaricus |
B. | Saccharomyces cerevisiae |
C. | Aspergillus niger |
D. | Streptococcus lactis |
Answer» D. Streptococcus lactis | |
25. |
In koji 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» B. A. niger floats on the surface of solution | |
26. |
Which of the following organism is not used in any of the traditional industrial fermentation? |
A. | E. coli |
B. | Yeast |
C. | Bacillus |
D. | Pseudomonas |
Answer» B. Yeast | |
27. |
Carbonic maceration wines |
A. | are made from crushed grapes |
B. | are very fruity white wines |
C. | are produced in California |
D. | are low tannin red wines |
Answer» E. | |
28. |
In submerged 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» D. both (a) and (b) | |
29. |
Yeast is used in the production of |
A. | ethyl alcohol |
B. | acetic acid |
C. | cheese |
D. | curd |
Answer» B. acetic acid | |
30. |
Chaptalization is |
A. | adding sucrose to must |
B. | adding grape juice to must |
C. | adding sugar to wine before bottling |
D. | adding grape juice to wine before bottling |
Answer» B. adding grape juice to must | |
31. |
A hydrometer |
A. | measures wine acid |
B. | requires a few drops of juice |
C. | measures alcohol in the wine |
D. | measures grape sugar |
Answer» E. | |
32. |
High ethanol concentration |
A. | promotes yeast growth |
B. | inhibits yeast growth |
C. | promotes bacterial growth |
D. | inhibits bacterial growth |
Answer» C. promotes bacterial growth | |
33. |
Malting process allows malt amylase and proteinases to degrade starch and protein to |
A. | glucose and peptone as well as peptides |
B. | glucose and amino acids |
C. | maltose and peptone as well as peptides |
D. | maltose and amino acids |
Answer» D. maltose and amino acids | |
34. |
Punching down is done |
A. | for the same reasons as pumping over |
B. | to extract tannin |
C. | both (a) and (b) |
D. | to keep the cap dry |
Answer» E. | |
35. |
In sparkling wine production, the cuvee is |
A. | the wire cage that holds the cork in place |
B. | the sugar addition just before corking |
C. | the sugar/yeast addition to the base wine |
D. | the base wine |
Answer» E. | |
36. |
Volatile acidity is |
A. | also known as total acidity |
B. | produced by acetobacter |
C. | produced by Brettanomyces |
D. | known for producing a mousy or barnyard aroma |
Answer» C. produced by Brettanomyces | |
37. |
Wort is boiled with the hops |
A. | to help in protein coagulation |
B. | to provide bitter taste and flavour to the beer |
C. | to help in the coagulation of tannins |
D. | All of the above |
Answer» C. to help in the coagulation of tannins | |
38. |
As the fermentation for the ethanol production is over, the cells are separated to get the biomass of yeast cells that is used |
A. | for next fermentation |
B. | as single cell protein for animal feed |
C. | as manure |
D. | all of the above |
Answer» C. as manure | |
39. |
Alegar is a type of vinegar produced from |
A. | fruit juices |
B. | malted grain |
C. | ethanol |
D. | ale |
Answer» E. | |
40. |
After storage and recarbonation, left over yeast is separated by |
A. | centrifugation |
B. | filtration |
C. | cell disruption |
D. | need not to be separated |
Answer» C. cell disruption | |
41. |
Spirit vinegar is produced from |
A. | fruit juices |
B. | malted grain |
C. | ethanol |
D. | ale |
Answer» D. ale | |
42. |
Which of the following is used for agitation in a fermentor? |
A. | Impeller |
B. | Baffles |
C. | Sparger |
D. | All of these |
Answer» B. Baffles | |
43. |
What is the pH of the medium when sucrose is used as substrate for the production of citric acid? |
A. | 3 |
B. | 4 |
C. | 5 |
D. | 6 |
Answer» B. 4 | |
44. |
Ales are the beer in which fermentation is carried out using |
A. | top yeast |
B. | bottom yeast |
C. | either of the above |
D. | middle yeast |
Answer» B. bottom yeast | |
45. |
Which is not correct about blush wines? |
A. | They are stored in barrels |
B. | They are bottled within a year |
C. | They are usually slightly sweet |
D. | They are fermented in stainless steel |
Answer» B. They are bottled within a year | |
46. |
Lagers are the beer in which fermentation is carried out using |
A. | top yeast |
B. | bottom yeast |
C. | either of these |
D. | middle yeast |
Answer» C. either of these | |
47. |
Cider vinegar is produced from |
A. | fruit juices |
B. | malted grain |
C. | ethanol |
D. | ale |
Answer» B. malted grain | |
48. |
Ethanol is produced by |
A. | continuous fermentation |
B. | batch fermentation |
C. | both (a) and (b) |
D. | none of these |
Answer» D. none of these | |
49. |
The term Racking refers to |
A. | stacking unlabeled wine in bins for aging |
B. | adding yeast to initiate fermentation |
C. | storing hoses to drain on a slanted board |
D. | removing clear liquid from sediment |
Answer» E. | |
50. |
During recovery step of citric acid, calcium citrate formed is treated with which of the following acid to precipitate calcium? |
A. | HCl |
B. | HNO3 |
C. | H2SO4 |
D. | None of these |
Answer» D. None of these | |