Organism

Cyanobacteria are multicellular prokaryotes.
Fungi are multicellular eukaryotes.

An organism (from Ancient Greek ὄργανον (órganon) 'instrument, implement, tool', and -ισμός (-ismós)) is any biological living system that functions as an individual life form.[1] All organisms are composed of cells.[1] The idea of organism is based on the concept of minimal functional unit of life. Three traits have been proposed to play the main role in qualification as an organism:

  • noncompartmentability – structure that cannot be divided without its functionality loss,[2]
  • individuality – the entity has simultaneous holding of genetic uniqueness, genetic homogeneity and autonomy,[3]
  • distinctness – genetic information has to maintain open-system (a cell).[4]

Organisms include multicellular animals, plants, and fungi; or unicellular microorganisms such as protists, bacteria, and archaea.[5] All types of organisms are capable of reproduction, growth and development, maintenance, and some degree of response to stimuli. Most multicellular organisms differentiate into specialized tissues and organs during their development.

In 2016, a set of 355 genes from the last universal common ancestor (LUCA) of all organisms from Earth was identified.

  1. ^ a b Mosby's Dictionary of Medicine, Nursing and Health Professions (10th ed.). St. Louis, Missouri: Elsevier. 2017. p. 1281. ISBN 978-0-3232-2205-1.
  2. ^ Rosen, Robert (September 1958). "A relational theory of biological systems". The Bulletin of Mathematical Biophysics. 20 (3): 245–260. doi:10.1007/BF02478302. ISSN 0007-4985.
  3. ^ Santelices, Bernabé (April 1999). "How many kinds of individual are there?". Trends in Ecology & Evolution. 14 (4): 152–155. doi:10.1016/S0169-5347(98)01519-5. PMID 10322523.
  4. ^ Piast, Radosław W. (June 2019). "Shannon's information, Bernal's biopoiesis and Bernoulli distribution as pillars for building a definition of life". Journal of Theoretical Biology. 470: 101–107. Bibcode:2019JThBi.470..101P. doi:10.1016/j.jtbi.2019.03.009. PMID 30876803. S2CID 80625250.
  5. ^ Hine, R.S. (2008). A dictionary of biology (6th ed.). Oxford: Oxford University Press. p. 461. ISBN 978-0-19-920462-5.