Organism
hideIn biology, an organism is any living system (such as animal, plant, fungus, or micro-organism). In at least some form, all organisms are capable of response to stimuli, reproduction, growth and development, and maintenance of homeostasis as a stable whole. An organism may either be unicellular (single-celled) or be composed of, as in humans, many billions of cells grouped into specialized tissues and organs. The term multicellular (many-celled) describes any organism made up of more than one cell.
The terms "organism" (Greek ὀργανισμός - organismos, from Ancient Greek ὄργανον - organon "organ, instrument, tool") first appeared in the English language in 1701 and took on its current definition by 1834 (Oxford English Dictionary).
Scientific classification in biology considers organisms synonymous with life on Earth. Based on cell type, organisms may be divided into the prokaryotic and eukaryotic groups. The prokaryotes represent two separate domains, the Bacteria and Archaea. Eukaryotic organisms, with a membrane-bounded cell nucleus, also contain organelles, namely mitochondria and (in plants) plastids, generally considered to be derived from endosymbiotic bacteria. Fungi, animals and plants are examples of species that are eukaryotes.
More recently a clade, Neomura, has been proposed, which groups together the Archaea and Eukarya. Neomura is thought to have evolved from Bacteria, more specifically from Actinobacteria.
For more information about Organism, read the full article at
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
News tagged with organisms
Scientists isolate new antifreeze molecule in Alaska beetle
Dec 14, 2009 |
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Scientists have identified a novel antifreeze molecule in a freeze-tolerant Alaska beetle able to survive temperatures below minus 100 degrees Fahrenheit. Unlike all previously described biological antifreezes that contain ...
Fossils on the Edge of Forever
Space & Earth / Earth Sciences
Dec 14, 2009 |
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Astrobiologists have not yet found alien life on other planets. But the fossil record has evidence of aliens of another sort: the Ediacarans that lived on Earth millions of years ago.
Peptides control crystal growth with 'switches, throttles and brakes'
Nanotechnology / Bio & Medicine
Nov 23, 2009 |
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(PhysOrg.com) -- By producing some of the highest resolution images of peptides attaching to mineral surfaces, scientists have a deeper understanding how biomolecules manipulate the growth crystals. This research ...
Acid test: Study reveals both losers and winners of CO2-induced ocean acidification
Space & Earth / Earth Sciences
Dec 01, 2009 |
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(PhysOrg.com) -- As the world’s seawater becomes more acidic due to rising atmospheric carbon dioxide, some shelled marine creatures may actually become bigger and stronger, according to a new study.
Scientists Reproduce a Building Block of Life in Laboratory
Nov 06, 2009 |
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(PhysOrg.com) -- NASA scientists studying the origin of life have reproduced uracil, a key component of our hereditary material, in the laboratory.
What is the meaning of 'one'? Evolutionary biologists argue for new meaning of 'organismality'
Nov 09, 2009 |
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Rice University evolutionary biologists David Queller and Joan Strassmann argue in a new paper that high cooperation and low conflict between components, from the genetic level on up, give a living thing its "organismality," ...
Mass Extinctions, Ancient Viruses May Hold Clues to Life’s Origins
Apr 03, 2009 |
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(PhysOrg.com) -- Mass extinctions occur repeatedly, though irregularly, throughout Earth’s history, and occasionally these extinctions have been devastating to life on our planet - or have they? Extinction ...
First discovery of life's building block in comet made
Space & Earth / Space Exploration
Aug 17, 2009 |
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(PhysOrg.com) -- NASA scientists have discovered glycine, a fundamental building block of life, in samples of comet Wild 2 returned by NASA's Stardust spacecraft.
Hydrocarbons in the deep Earth?
Space & Earth / Earth Sciences
Jul 26, 2009 |
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The oil and gas that fuels our homes and cars started out as living organisms that died, were compressed, and heated under heavy layers of sediments in the Earth's crust. Scientists have debated for years ...
Scientists discover Amazon river is 11 million years old
Space & Earth / Earth Sciences
Jul 29, 2009 |
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Researchers at the University of Liverpool have discovered that the Amazon river, and its transcontinental drainage, is around 11 million years old and took its present shape about 2.4 million years ago.
Earliest animals lived in a lake environment, research shows
Other Sciences / Archaeology & Fossils
Jul 27, 2009 |
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Evidence for life on Earth stretches back billions of years, with simple single-celled organisms like bacteria dominating the record. When multi-celled animal life appeared on the planet after 3 billion years ...
UK starts study on using human DNA in animals
Nov 09, 2009 |
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(AP) -- British scientists begin a new study on Tuesday to consider how human DNA is used in animal experiments and to determine what the boundaries of such controversial science might be.
Mars explorer says we'll find life on other planets within 10 years
Space & Earth / Space Exploration
Apr 21, 2009 |
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Within 10 years, we'll find life outside Earth -- that's the prediction of Peter Smith, the University of Arizona professor who led NASA's Phoenix Mars Mission.
Researchers Find Key 'Conductor' of Nature's Synchronicity
Jul 22, 2009 |
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(PhysOrg.com) -- Synchronicity in nature is seen in beating hearts, the flashing of fireflies' lights, the ebb and flow of infectious disease—and the simultaneous rise and fall of populations across vast reaches ...
Bacteria expect the unexpected: Scientists observe the emergence of a new adaptation strategy
Nov 04, 2009 |
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Organisms ensure the survival of their species by genetically adapting to the environment. If environmental conditions change too rapidly, the extinction of a species may be the consequence. A strategy to ...
