AP BIOLOGY

Detailed explanation-1: -Bacteria are the most abundant microbes in the soil. They are single celled organisms, and there can be billions of bacteria in a single gram of soil. Populations of bacteria can boom or bust in the space of a few days in response to changes in soil moisture, soil temperature or carbon substrate.

Detailed explanation-2: -By far, the most numerous microbes in soil are bacteria, which have just one cell. Also abundant are fungi, which produce long, slender strings of cells called filaments, or hyphae. The actinomycetes are in-between these two organisms. They are advanced bacteria that can form branches like fungi.

Detailed explanation-3: -Soil microorganisms, including bacteria, fungi, viruses, protozoa, and archaea (Tate, 2000), are essential for the growth of plants by providing nutrients7 to the plants, through the process of mineralization of organic content.

Detailed explanation-4: -There are basically four functional soil bacteria groups including decomposers, mutalists, pathogens and lithotrophs. Decomposer bacteria consume simple sugars and simple carbon compounds, while mutualistic bacteria form partnerships with plants including the nitrogen-fixing bacteria (Rhizobia).