Organism

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In 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

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Scientists Reproduce a Building Block of Life in Laboratory

Scientists Reproduce a Building Block of Life in Laboratory

Chemistry / Biochemistry

created Nov 06, 2009 | popularity 4.8 / 5 (23) | comments 0

(PhysOrg.com) -- NASA scientists studying the origin of life have reproduced uracil, a key component of our hereditary material, in the laboratory.


Caribbean, Gulf spared widespread coral damage

Space & Earth / Environment

created Nov 06, 2009 | popularity 3 / 5 (2) | comments 1

(AP) -- Lower-than-feared sea temperatures this summer gave a break to fragile coral reefs across the Caribbean and the central Gulf of Mexico that were damaged in recent years, scientists said Thursday.


Bacteria expect the unexpected

Bacteria expect the unexpected: Scientists observe the emergence of a new adaptation strategy

Biology / Cell & Microbiology

created Nov 04, 2009 | popularity 4.7 / 5 (3) | comments 0

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 ...


GSU professor develops new method to help keep fruit, vegetables and flowers fresh

Biology / Cell & Microbiology

created Oct 20, 2009 | popularity 5 / 5 (2) | comments 0

Did you know that millions of tons of fruits and vegetables in the United States end up in the trash can before being eaten, according to the U.S. Department of Agriculture? A Georgia State University professor has developed ...


How does a worm build a throat?

How does a worm build a throat? Tackling the 'organ formation puzzle'

Biology / Cell & Microbiology

created Oct 06, 2009 | popularity 4.8 / 5 (5) | comments 0

(PhysOrg.com) -- Mention worms to most people, and they probably think of fishing, gardening, or trips to the vet. Mention them to Susan E. Mango, and she begins telling you how “absolutely beautiful” they ...


How mitochondrial gene defects impair respiration, other major life functions

Medicine & Health / Research

created Sep 24, 2009 | popularity 5 / 5 (1) | comments 0

Researchers are delving into abnormal gene function in mitochondria, structures within cells that power our lives. Mitochondria are the place where energy is generated from the most basic molecules of food. Because this function ...


Photoswitches shed light on spontaneous free swimming in zebrafish (w/ Video)

Biology / Biotechnology

created Sep 16, 2009 | popularity not rated yet | comments 0

A new way to select and switch on one cell type in an organism using light has helped answer a long-standing question about the function of one class of enigmatic nerve cells in the spinal cord.


Ocean acidification: impact on key organisms of oceanic fauna

Ocean acidification: impact on key organisms of oceanic fauna

Space & Earth / Environment

created Sep 15, 2009 | popularity 3.2 / 5 (5) | comments 0

In addition to global warming, carbon dioxide emissions cause another, less well-known but equally serious and worrying phenomenon: ocean acidification. Researchers in the Laboratoire d'Océanographie ...


Digging deeper below Antarctica's Lake Vida

Space & Earth / Earth Sciences

created Sep 14, 2009 | popularity 4.5 / 5 (8) | comments 1

(PhysOrg.com) -- Antarctica's Lake Vida, a geologic curiosity that is essentially an ice bottle of brine, is home to some of the oldest and coldest living organisms on Earth. Perpetually covered by more than 60 feet of ice, ...


Study Reveals Unexpected Ancient Cellular Structure

Biology / Cell & Microbiology

created Sep 10, 2009 | popularity 5 / 5 (2) | comments 0

(PhysOrg.com) -- Scientists at North Carolina State University have effectively lifted the veil from the structure of an ancient and important RNA-protein complex essential for the biosynthesis and function of the ribosome, ...


NASA researchers make first discovery of life's building block in comet

First discovery of life's building block in comet made

Space & Earth / Space Exploration

created Aug 17, 2009 | popularity 4.5 / 5 (17) | comments 13

(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.


Some mice stem cells divide in unexpected ways

Some mice stem cells divide in unexpected ways

Biology / Cell & Microbiology

created Aug 14, 2009 | popularity 4.8 / 5 (6) | comments 0

(PhysOrg.com) -- Using new genetic tools, Cornell researchers have found that some stem cells in mice behave dramatically different than in fruit flies, where most of the pioneering stem cell work has been ...


Parasites ready to jump: How the cell represses mobile genetic elements

Biology / Cell & Microbiology

created Jul 31, 2009 | popularity 4 / 5 (1) | comments 0

Transposons are mobile genetic elements found in the hereditary material of humans and other organisms. They can replicate and the new copies can insert at novel sites in the genome. Because this threatens the whole organism, ...


Amazon river

Scientists discover Amazon river is 11 million years old

Space & Earth / Earth Sciences

created Jul 29, 2009 | popularity 4.4 / 5 (7) | comments 4

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

Earliest animals lived in a lake environment, research shows

Other Sciences / Archaeology & Fossils

created Jul 27, 2009 | popularity 4.4 / 5 (7) | comments 3

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 ...