EVERYDAY SCIENCE

Detailed explanation-1: -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.

Detailed explanation-2: -Prokaryotic cells are believed to be the oldest cells on Earth. Thus, all bacteria are prokaryotic, but not all prokaryotes are bacteria. The other major group of prokaryotes is the blue green algae (also known as cyanobacteria).

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 lack a membrane-bound nucleus and other internal structures and are therefore ranked among the unicellular life-forms called prokaryotes.

Detailed explanation-5: -The bacteria are the oldest and simplest living organisms, and all of the bacteria are “prokaryotes, ” meaning that they do not have a true membrane-bound nucleus as eukaryotes do. [Prokaryote is derived from Greek, meaning “before nucleus"; eukaryote means “true nucleus."]