Given below are two statements: one is labelled as Assertion (A) and the other…
2020
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): The problem of organic pollution in rivers is usually worse in hot summer months.
Reason (R): Higher water temperatures exacerbate dissolved oxygen depletion.
In the light of the above statements, choose the most appropriate answer from the options given below:
- A.
Both (A) and (R) are correct and (R) is the correct explanation of (A)
- B.
Both (A) and (R) are correct but (R) is NOT the correct explanation of (A)
- C.
(A) is correct but (R) is not correct
- D.
(A) is not correct but (R) is correct
Attempted by 3 students.
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Correct answer: A
Organic pollution adds oxygen-demanding matter to rivers. Microorganisms decompose this matter and consume dissolved oxygen. During hot summer months, water temperature rises; warm water holds less dissolved oxygen and biological activity/decomposition generally increases. Thus oxygen depletion becomes more severe, making organic pollution worse. Therefore, both (A) and (R) are correct, and (R) is the correct explanation of (A).