AP BIOLOGY

Detailed explanation-1: -Plant and animal wastes decompose, adding nitrogen to the soil. Bacteria in the soil convert those forms of nitrogen into forms plants can use. Plants use the nitrogen in the soil to grow. People and animals eat the plants; then animal and plant residues return nitrogen to the soil again, completing the cycle.

Detailed explanation-2: -This process is called nitrification. Compounds such as nitrate, nitrite, ammonia and ammonium can be taken up from soils by plants and then used in the formation of plant and animal proteins. An interactive showing the main components of the terrestrial nitrogen cycle.

Detailed explanation-3: -The nitrogen is passed through the food chain by animals that consume the plants, and then released into the soil by decomposer bacteria when they die.

Detailed explanation-4: -The nitrogen compounds are passed through the food chain as other organisms feed on the plants and each other. Waste products (undigested food, urine and faeces) and dead organisms which contain nitrogen compounds are added to the soil.