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: -Healthy soils exhibited a higher microbial diversity and abundance of beneficial microbes such as Bacillus, Agromyces, Micromonospora, Pseudonocardia, Acremonium, Lysobacter, Mesorhizobium, Microvirga, Bradyrhizobium, Acremonium and Chaetomium, but a lower abundance of pathogens such as R. solanacearum.

Detailed explanation-4: -A teaspoon of productive soil generally contains between 100 million and 1 billion bacteria. That is as much mass as two cows per acre. A ton of microscopic bacteria may be active in each acre.” While bacteria may be small, they make up both the largest number and biomass (weight) of any soil microorganism.

Detailed explanation-5: -Most soil microbes can be classified as fungi, bacteria, archaea, protozoa, or viruses. It has been estimated that a single gram of soil can contain up to several billion bacteria alone.