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Q. No.Consider the given two statements:
| Assertion (A): | The large holes in Swiss cheese are formed due to the release of carbon dioxide by Propionibacterium sharmanii during fermentation. |
| Reason (R): | Propionibacterium sharmanii ferments lactose into lactic acid, which produces large quantities of carbon dioxide. |
| 1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
| 2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
| 3. | (A) is True but (R) is False. |
| 4. | Both (A) and (R) are False. |
Subtopic: Â Microbes in Household Products |
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Consider the given two statements:
| Assertion (A): | Alcoholic fermentation by yeast is used in the production of bread |
| Reason (R): | Alcoholic fermentation by yeast produces ethanol. |
| 1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
| 2. | Both (A) and (R) are True but (R) is not the correct explanation of (A) |
| 3. | (A) is True but (R) is False. |
| 4. | (A) is False but (R) is True. |
Subtopic: Â Industrial Products, Beverages & Antibiotics |
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Which of the following accurately describes the competitive action of statins produced by Monascus purpureus?
| 1. | They inhibit the enzyme responsible for blood clot formation. |
| 2. | They block the metabolic pathway leading to cholesterol biosynthesis. |
| 3. | They destroy pathogenic microbes in the bloodstream. |
| 4. | They enhance the immune response to suppress cholesterol accumulation. |
Subtopic: Â Chemicals, Enzymes & Other Bioactive Molecules |
From NCERT
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Consider the two statements:
| I: | Biochemical oxygen demand (BOD) is often used as an indicator of the degree of organic pollution of water. |
| II: | An increase in BOD is used as a gauge of the effectiveness of wastewater treatment plants. |
| 1. | Only I is correct | 2. | Only II is correct |
| 3. | Both I and II are correct | 4. | Both I and II are incorrect |
Subtopic: Â Microbes in Sewage Treatment |
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Consider the given two statements:
Choose the correct option.
| Assertion (A): | Secondary treatment of sewage water involves the use of aerobic bacteria. |
| Reason (R): | Aerobic bacteria break down organic matter into inorganic substances like \(\text{CO}_2\) and \(\text{H}_2 \text{O}\). |
| 1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
| 2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
| 3. | (A) is True but (R) is False. |
| 4. | (A) is False but (R) is True. |
Subtopic: Â Microbes in Sewage Treatment |
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From NCERT
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If oxygen availability to activated sludge flocs in a sewage treatment plant is reduced:
| 1. | the rate of degradation of organic matter slows down |
| 2. | the center of flocs becomes anoxic, causing death of bacteria and eventually breakage of flocs. |
| 3. | the flocs would increase in size as anaerobic bacteria would grow around flocs. |
| 4. | Protozoa would grow in large numbers. |
Subtopic: Â Microbes in Sewage Treatment |
From NCERT
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Which of the following is used to estimate the biochemical oxygen demand and hence the polluting potential of a sample of water?
1. total organic matter
2. biodegradable organic matter
3. oxygen evolution
4. oxygen consumption
1. total organic matter
2. biodegradable organic matter
3. oxygen evolution
4. oxygen consumption
Subtopic: Â Microbes in Sewage Treatment |
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From NCERT
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How many of the given statements are true?
1. 1
2. 2
3. 3
4. 4
| I: | BOD refers to the amount of oxygen that would be consumed if all the organic matter in one litre of water were oxidised by bacteria. |
| II: | The sewage water is treated until BOD reduces to zero. |
| III: | The BOD test measures the rate of uptake of oxygen by micro-organisms in a sample of water and thus, indirectly, BOD is a measure of the organic matter present in the water. |
| IV: | The greater the BOD of waste water, greater is its polluting potential. |
2. 2
3. 3
4. 4
Subtopic: Â Microbes in Sewage Treatment |
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The primary objective of anaerobic sludge digestion in sewage treatment is:
1. removal of nutrients from the polluted water
2. methane production
3. disinfection
4. promotion of growth of algae and cyanobacteria
1. removal of nutrients from the polluted water
2. methane production
3. disinfection
4. promotion of growth of algae and cyanobacteria
Subtopic: Â Microbes in Sewage Treatment |
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From NCERT
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Consider the given two statements:
| Assertion (A): | The sewage water is treated till the Biological Oxygen Demand (BOD) is reduced. |
| Reason (R): | BOD indicates the rate of uptake of oxygen by microorganisms in a sample of water. |
| 1. | Both (A) and (R) are True and (R) explains (A). |
| 2. | Both (A) and (R) are True but (R) does not explain (A). |
| 3. | (A) is True but (R) is False. |
| 4. | (A) is False but (R) is True. |
Subtopic: Â Microbes in Sewage Treatment |
 56%
From NCERT
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