AIIMS 2019 Botany Eutrophication MCQ Question

Eutrophication occurs when excess phosphates (PO₄³⁻) from agricultural runoff and wastewater enter water bodies, leading to algal blooms. These blooms block sunlight and deplete dissolved oxygen (O₂) as algae decompose, resulting in hypoxic conditions that can harm aquatic life. Other options are not relevant as they do not address the specific relationship between phosphate pollution and the reduction of dissolved oxygen in water. Understanding this process highlights the importance of managing nutrient inputs to maintain healthy aquatic ecosystems.