AP BIOLOGY

Detailed explanation-1: -Decomposers or saprotrophs recycle dead plants and animals into chemical nutrients like carbon and nitrogen that are released back into the soil, air and water.

Detailed explanation-2: -Nitrogen is returned to the atmosphere by the activity of organisms known as decomposers. Some bacteria are decomposers and break down the complex nitrogen compounds in dead organisms and animal wastes.

Detailed explanation-3: -Most decomposers are microscopic organisms, including protozoa and bacteria. Other decomposers are big enough to see without a microscope. They include fungi along with invertebrate organisms sometimes called detritivores, which include earthworms, termites, and millipedes.

Detailed explanation-4: -Many heterotrophic bacteria live in the soil and fix significant levels of nitrogen without the direct interaction with other organisms. Examples of this type of nitrogen-fixing bacteria include species of Azotobacter, Bacillus, Clostridium, and Klebsiella.

Detailed explanation-5: -Saprophytes are decay organisms and are responsible for getting dead animals and plants to rot (decompose). They break down the remains into simple chemicals e.g., nitrates which contain nitrogen, an important element needed by plants.