What are the main categories of the organism?
organisms are usually categorized according to the system of three domains introduced by Carl Woees in 1990. There are three domains of life in the Woese classification: bacteria, archaea and eucaryota.
It is also considered to add the fourth domain, acytota, which means "without cells", represent viruses and other pseudo-organisms without cells such as prions. Even more speculative is the organisms of the fifth domain, nanobiot, which can represent an extremely small, life filelamental structures found in some minerals. More recently, in 2002, some scientists considered Archaea and Eucaryota to be part of the same domain.
The most important division in life is generally considered to be divided between prokaryotic organisms (nuclei cells) and eukaryotic organisms (with nuclei). A little less significant, but still very important, the distinction is between unicellular and multicellular organisms and between plants and animals.
If viruses are eventually recognized as a valid form of life, then theThe more common division happened whether the form of life is cell -based. Possible admission of viruses to the kingdom of life has begun by discovery of Mimivir, a very large DNA virus with genes encoding for nucleotides and amino acid synthesis, which even some bacteria are missing.
Another big difference in the category is that between aerobic (oxygen breathing) and anaerobic (unnecessary oxygen) organisms. Once, when the Earth's atmosphere was primarily carbon dioxide, the Earth was covered with anaerobic organisms, but many of them died out during the oxygen disaster, a long period during which aerobic organisms increased to importance and released a large amount of toxic oxygen to anaerobic organisms. Now the anaerobic organisms are often seen in compost piles.
If life is discovered on another planet, it would represent an even more fundamental division in life. The term used for the wheelsEcticly designation on earth organisms is Gaeabiot . Sometimes the oldest ordinary predecessor of earthly life is called Luca, who means "the last universal common ancestor". It is assumed that Luca lived between 3.6 and 4.1 billion years