AP BIOLOGY

Detailed explanation-1: -When plants or animals die, the nitrogen present in the organic matter is released back into the soil. The decomposers, namely bacteria or fungi present in the soil, convert the organic matter back into ammonium. This process of decomposition produces ammonia, which is further used for other biological processes.

Detailed explanation-2: -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-3: -Decomposition. Plants take up nitrogen compounds through their roots. Animals obtain these compounds when they eat the plants.

Detailed explanation-4: -Simply by eating, all living things take in these molecules and break them down in their own bodies in order to use them. When animals die, they contribute to the nitrogen cycle as well. Nitrogen-rich compounds from bodies of animals are decomposed, and nitrogen is returned to the soil to be recycled and re-used.

Detailed explanation-5: -The decomposers consume the organic matter, and the nitrogen contained in the dead organism is converted to ammonium ions. The ammonium is then converted to nitrates by the nitrifying bacteria.