Assertion(A): Bacteria can utilize some of the components of sewage.
Reason(R): Bacteria can multiply using organic substances present in sewage as substrates.
Choices for Assertions and reasons:
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:  Water Pollution |
 80%
From NCERT
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Assertion(A): When the water flows through the marshes, it gets purified naturally.
Reason(R): Plants, algae, fungi, and bacteria were seeded into these marshes which neutralize, absorb and assimilate the pollutants.
Choices for Assertions and reasons:
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:  Water Pollution |
 88%
From NCERT
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Assertion(A): Cl atoms are not consumed in the reaction where ozone gets degraded to release oxygen under the influence of Cl atoms.
Reason(R): Whatever CFCs are added to the stratosphere, they have permanent and continuing effects on Ozone levels.
Choices for Assertions and reasons:
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:  Ozone Layer Depletion |
 51%
From NCERT
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Assertion(A): Motor vehicles equipped with catalytic converters should use unleaded petrol.
Reason(R): Lead over stimulates the catalyst platinum.
Choices for Assertions and reasons:
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:  Air Pollution |
 66%
From NCERT
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Assertion(A): Biomagnification refers to an increase in the concentration of the toxicant at successive trophic levels.
Reason(R): These toxic substances can be metabolized partially and can be excreted out of the body when it is required.
Choices for Assertions and reasons:
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:  Water Pollution: I |
 79%
From NCERT
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Assertion(A): Radiation, that is given off by nuclear waste is extremely damaging to prokaryotic organisms only.
Reason(R): Radiation causes mutation at a very high rate.
Choices for Assertions and reasons:
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:  Agrochemical & Radioactive Waste |
 86%
From NCERT
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Assertion(A): Carbon monoxide and methane – are commonly known as greenhouse gases.
Reason(R): Greenhouse gases are responsible for global warming.
Choices for Assertions and reasons:
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:  Green House Effect & Global Warming |
 59%
From NCERT
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Assertion(A): One of the major effects of deforestation is enhanced carbon dioxide concentration in the atmosphere.
Reason(R): The trees that could hold a lot of carbon in their biomass are lost with deforestation.
Choices for Assertions and reasons:
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:  Agrochemical & Radioactive Waste |
 78%
From NCERT
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Assertion(A): Landfills are not much useful.
Reason(R): The amount of garbage generation especially in rural areas has increased.
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:  Solid Waste Pollution |
 53%
From NCERT
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Assertion(A): DNA and proteins of living organisms preferentially absorb UV rays.
Reason(R): The high energy of UV rays breaks chemical bonds in DNA and proteins.
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:  Ozone Layer Depletion |
 52%
From NCERT
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