Answer: Biological Oxygen Demand - amount of oxygen consumed by microorganisms to decompose organic matter in water.
- A Biological Oxygen Demand - amount of oxygen consumed by microorganisms to decompose organic matter in water
- B Bacterial Oxygen Demand - the volume of oxygen gas bacteria release during respiration overall in most cases
- C Biochemical Oxygen Deficit - the concentration of dissolved carbon dioxide in a water sample under typical conditions
- D Basic Oxygen Dilution - a measure of the pH and turbidity of water according to standard textbooks in general practice
Correct answer: A. Biological Oxygen Demand - amount of oxygen consumed by microorganisms to decompose organic matter in water
Explanation: BOD (Biological Oxygen Demand) measures the amount of oxygen consumed by microorganisms while decomposing organic matter in water. High BOD indicates high organic pollution and poor water quality (less dissolved oxygen available for fish and other aquatic life).
Sunlight passes through the atmosphere and warms the surface; the surface re-radiates this energy as infrared heat, which greenhouse gases (CO₂, CH₄, water vapour) absorb and trap - a naturally beneficial process that intensifies into global warming as gas concentrations rise from human activity.
Concept context
Pollution, global warming, ozone depletion, deforestation, and sustainability. Important for NEET and general awareness.