GENERAL HISTOLOGY

Detailed explanation-1: -The two prokaryotic domains (Archaea and Bacteria) each comprise several smaller taxonomic groupings. Within the Archaea are the euryarchaeotes, crenarchaeotes, nanoarchaeotes, and korarchaeotes. Within the Bacteria are proteobacteria, chlamydias, spirochetes, cyanobacteria, and gram-positive bacteria.

Detailed explanation-2: -Examples of prokaryotes are blue-green algae, bacteria and mycoplasma. Among prokaryotes, bacteria are the most common and multiply very fast. They are single-celled and range in size from 0.2 to 10 microns (about 10 times smaller than most plant and animal cells).

Detailed explanation-3: -In the two-empire system arising from the work of Édouard Chatton, prokaryotes were classified within the empire Prokaryota. But in the three-domain system, based upon molecular analysis, prokaryotes are divided into two domains: Bacteria (formerly Eubacteria) and Archaea (formerly Archaebacteria).

Detailed explanation-4: -Bacteria are classified as prokaryotes, along with another group of single-celled organisms, the archaea. Prokaryotes are tiny, but in a very real sense, they dominate the Earth. They live nearly everywhere – on every surface, on land and in water, and even inside of our bodies.