- A A type of soil erosion caused specifically by overgrazing of grasslands and the unchecked clearing of forest cover over time
- B Excessive algal growth in water bodies due to excess nutrients (nitrogen and phosphorus), leading to oxygen depletion
- C An increase in water pH caused by the very gradual dissolution of carbonate mineral deposits over many decades
- D Desertification of previously fertile agricultural land due to prolonged seasonal drought conditions across multiple years
Correct answer: B. Excessive algal growth in water bodies due to excess nutrients (nitrogen and phosphorus), leading to oxygen depletion
Explanation: Eutrophication: excess nutrients (N, P from fertilizers/sewage) cause massive algal blooms. When algae die, decomposition consumes oxygen (dead zone). Fish and other organisms suffocate. Lakes and coastal waters are most affected. Solution: reduce nutrient runoff.
Concept context
Pollution, global warming, ozone depletion, deforestation, and sustainability. Important for NEET and general awareness.