BOD is the amount of oxygen required by bacteria to break down organic materials present in water.
What is the importance of measuring BOD of a water body?

BOD is the amount of oxygen required by bacteria to break down organic materials present in water. Why does water covered with excessive algai growth become polluted.

Break down of complex organic matter into inorganic raw material like CO_2 , water and various nutrient by micro organism _____

Organic matter such as leaves, grass, etc are major pollutants in air. What is biochemical oxygen demand (BOD) ?