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.
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News tagged with organisms
'Junk' DNA proves functional
Nov 04, 2008 |
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In a paper published in Genome Research on Nov. 4, scientists at the Genome Institute of Singapore (GIS) report that what was previously believed to be "junk" DNA is one of the important ingredients distinguishing humans ...
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.
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 ...
Natural selection may not produce the best organisms
Biology /
Jul 18, 2008 |
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"Survival of the fittest" is the catch phrase of evolution by natural selection. While natural selection favors the most fit organisms around, evolutionary biologists have long wondered whether this leads to the best possible ...
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 ...
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.
Chemists see first building blocks to life on Earth
May 13, 2009 |
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Scientists at The University of Manchester have developed an experiment that sheds new and fascinating light on how life on Earth might have begun.
Canada's shores saved animals from devastating climate change 252 million years ago
Space & Earth / Earth Sciences
Oct 01, 2008 |
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The shorelines of ancient Alberta, British Columbia and the Canadian Arctic were an important refuge for some of the world's earliest animals, most of which were wiped out by a mysterious global extinction event some 252 ...
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.
How evolution learns from past environments to adapt to new environments
Biology /
Nov 07, 2008 |
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The evolution of novel characteristics within organisms can be enhanced when environments change in a systematic manner, according to a new study by Weizmann Institute researchers. Merav Parter, Nadav Kashtan and Uri Alon ...
Acidifying oceans add urgency to CO2 cuts
Space & Earth / Earth Sciences
Jul 03, 2008 |
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It's not just about climate change anymore. Besides loading the atmosphere with heat-trapping greenhouse gases, human emissions of carbon dioxide have also begun to alter the chemistry of the ocean—often called the cradle ...
The Amazon River is 11 million years old
Space & Earth / Earth Sciences
Jul 07, 2009 |
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The Amazon River originated as a transcontinental river around 11 million years ago and took its present shape approximately 2.4 million years ago. These are the most significant results of a study on two ...
Crossed (evolutionary) signals?
Biology /
Jul 01, 2008 |
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What do humans and single-celled choanoflagellates have in common? More than you'd think. New research into the choanoflagellate genome shows these ancient organisms have similar levels of proteins that cells ...
In Ocean's Depths, Heat-Loving 'Extremophile' Evolves a Strange Molecular Trick
Apr 30, 2009 |
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(PhysOrg.com) -- Making its home near extreme temperatures of thermal vents on the ocean floor, the organism Methanopyrus kandleri harbors a molecular secret that intrigues evolutionary biologists and even ...
Study of protein structures reveals key events in evolutionary history
Mar 10, 2009 |
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A new study of proteins, the molecular machines that drive all life, also sheds light on the history of living organisms.
