AP BIOLOGY

Detailed explanation-1: -By eating plants and other animals.

Detailed explanation-2: -Some animals also eat other animals as food. They get their nitrogen by eating other animals. When plants and animals die, the complex nitrogenous compounds present in their bodies are decomposed and converted into simple nitrogen compounds. This is done by certain bacteria and fungi (decomposers).

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

Detailed explanation-4: -Animals obtain nitrogen primarily from their diet. Carnivorous animals obtain their needed nitrogen from protein in the meat they eat while herbivorous animals obtain nitrogen through plant materials that has a high protein or amino acid content such as leguminous plants.