Prokaryotes

One main element that make up the composition of the earth’s biota, are prokaryotes.

These prokaryotes are organisms that are made up of cells that has no membrane bound nucleus. These are known as unicellular organisms. They are not visible under normal viewing conditions, and they inhabit so many different habitats that trying to count their numbers would be an endless task. Researchers has estimated that these prokaryotes are found in three main environments, soil, seawater and the subsurface that contain a combination of sediment/soil. In one research study conducted by Demming and Baross, the abyssal plain and the continental rise were examined to attempt to calculate the amount of prokaryotes in the open ocean, this was done using the arithmetic average of the cellular densities. In the colder polar environment, they can be found where the ice meets the water. A study by Delille and Rosiers calculated the mean cell numbers using the areal extent of the seasonal ice flowing in the Antarctic sea. The soil is maybe the primary source of prokaryotes to be found on earth. They are a very important element in the decomposition subsystem that changes plant life and animal matter into decomposed organics that make up important food webs. At the subsurface level, which is defined as around 10 centimeters below the sea surface for marine sediments and around 8 centimeters below the ground for terrestrial areas, the problem of finding uncontaminated biomass is very difficult, but it is estimated that there are huge quantities of prokaryotes. The theory is that the subsurface is a major source of prokaryotes, and this amount could be far more than the amounts found in other areas of the biosphere.

Another habitat where prokaryotes can be found are in animals, lots of invertebrate and also vertebrate animals very dense populations of prokaryotes. These prokaryotes help in the nutrition cycle and they also help to control diseases. In order to estimate the exact...