🩺 NEET🧬 Biology

Environmental Issues

1 solved NEET Biology previous year questions on Environmental Issues, each with the correct answer and a full explanation.

A river with an inflow of domestic sewage rich in organic waste may result in:

aIncreased population of aquatic food web organisms

bAn increased production of fish due to biodegradable nutrients

cDeath of fish due to lack of oxygen

dDrying of the river very soon due to algal bloom

✓ Correct answer: c) Death of fish due to lack of oxygen

ExplanationWhen domestic sewage rich in organic waste enters a river, it increases the biochemical oxygen demand (BOD) due to microbial decomposition.This leads to oxygen depletion in water, thus causing the death of fish and other aquatic organisms due to a lack of dissolved oxygen.Hence, the correct answer is option C.

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