Prokaryotic Domains, Names and Classifications
All Living Organisms can be Divided into 3 Domains as Follows:
All archaea are considered prokaryotic. Used to be considered bacteria, but now seen as a distinctly different cell having features in common with both prokaryotic and eukaryotic cells. Archaea and bacteria are thought to be the first life forms on Earth 3.5 billion years ago.
All bacteria are considered prokaryotic. Does not have compartmentalization – no membrane-bound organelles or nucleus. Archaea and bacteria are thought to be the first life forms on Earth 3.5 billion years ago.
There are 4 types of eukaryotic organisms (called kingdoms). Plants Animals Fungi Protists. The eukaryotic organisms commonly studied in microbiology include algae, protozoa, fungi, and helminths. Microscopic fungi include molds and yeasts. Helminths are multicellular parasitic worms. They are included in the field of microbiology because their eggs and larvae are often microscopic. Algae are plant-like organisms that can be either unicellular or multicellular, and derive energy via photosynthesis. Protozoa are unicellular organisms with complex cell structures; most are motile.
Viruses are acellular microorganisms that require a host to reproduce. They are not considered "alive", but they are a significant part of microbiology.
BACTERIA AND ARCHAEA
BACTERIA AND ARCHAEA are both prokaryotic single-celled organisms.
Many of the bacteria and archaea species discovered were found to be extremophiles that thrived in harsh conditions that would have killed your average life form. Some were found to grow best at temperatures above the boiling point of water or in toxic, acidic waste. Others were found to live completely independent of sunlight or oxygen and produced methane gas.