AP BIOLOGY

Detailed explanation-1: -Plants take up nitrogen compounds through their roots. Animals obtain these compounds when they eat the plants. When plants and animals die or when animals excrete wastes, the nitrogen compounds in the organic matter re-enter the soil where they are broken down by microorganisms, known as decomposers.

Detailed explanation-2: -Animals get the nitrogen they need by eating plants or other animals that contain nitrogen. When organisms die, their bodies decompose bringing the nitrogen into soil on land or into ocean water. Bacteria alter the nitrogen into a form that plants are able to use.

Detailed explanation-3: -The plants absorb the usable nitrogen compounds from the soil through their roots. Then, these nitrogen compounds are used for the production of proteins and other compounds in the plant cell. Animals assimilate nitrogen by consuming these plants or other animals that contain nitrogen.

Detailed explanation-4: -Consumers (herbivores and predators) get nitrogen compounds from the plants and animals they eat. Nitrogen returns to the soil when organisms release waste or die and are decomposed by bacteria and fungi.