Given below are two statements. In the light of the above statements, choose the most appropriate answer from the options given below:

Statement I:Turbulent and rapidly flowing waters are generally depleted in oxygen.

Statement II:Adding organic materials, such as sewage or paper pulp, to water stimulates activity and oxygen consumption by decomposers.

ABoth Statement I and Statement II are correct

BBoth Statement I and Statement II are incorrect

CStatement I is correct but Statement II is incorrect

DStatement I is incorrect but Statement II is correct ✓ Correct

Correct answer: (D) Statement I is incorrect but Statement II is correct

Explanation

Turbulent, rapidly flowing water actually mixes with air and stays well supplied with dissolved oxygen.

Statement 1 is wrong because such churning water is oxygen-rich, not oxygen-depleted.

Statement 2 is correct because sewage or paper pulp adds organic matter that decomposers break down while consuming large amounts of oxygen.

This microbial oxygen demand is measured as the biochemical oxygen demand of the water.

Heavy organic loading can drop dissolved oxygen so low that fish and other aquatic life suffocate.

Aeration and treatment of effluent help restore oxygen levels in polluted streams.

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