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


Peptides control crystal growth with 'switches, throttles and brakes'

Peptides control crystal growth with 'switches, throttles and brakes'

Nanotechnology / Bio & Medicine

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

(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 ...





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'Safety valve' protects photosynthesis from too much light

Biology / Cell & Microbiology

created Nov 25, 2009 | popularity 4.7 / 5 (3) | comments 0

Photosynthetic organisms need to cope with a wide range of light intensities, which can change over timescales of seconds to minutes. Too much light can damage the photosynthetic machinery and cause cell death. Scientists ...


Ice Cold: Cooler Than Being Cool

Ice Cold: Cooler Than Being Cool

Biology / Cell & Microbiology

created Nov 24, 2009 | popularity 4.2 / 5 (10) | comments 0

(PhysOrg.com) -- Water expands when it freezes. Anyone who has ever left a can of soda or bottle of water in the freezer too long has witnessed this first hand. So how do plants and animals survive severe ...


First-ever blueprint of a minimal cell is more complex than expected

First-ever blueprint of a minimal cell is more complex than expected

Biology / Cell & Microbiology

created Nov 26, 2009 | popularity 4.9 / 5 (19) | comments 4

What are the bare essentials of life, the indispensable ingredients required to produce a cell that can survive on its own? Can we describe the molecular anatomy of a cell, and understand how an entire organism ...


Aquatic creatures mix ocean water

Physics / General Physics

created Nov 22, 2009 | popularity 5 / 5 (4) | comments 1

Understanding mixing in the ocean is of fundamental importance to modeling climate change or predicting the effects of an El Niño on our weather. Modern ocean models primarily incorporate the effects of winds and tides. However, ...


Living buildings could mop up carbon dioxide

Living buildings could mop up carbon dioxide

Other Sciences / Other

created Nov 27, 2009 | popularity 1 / 5 (2) | comments 0

(PhysOrg.com) -- Architecture could help us tackle climate change, if we start to design our buildings with 'living' materials, according to Dr Rachel Armstrong, UCL Bartlett School of Architecture.


Bioengineers succeed in producing plastic without the use of fossil fuels

Biology / Biotechnology

created Nov 23, 2009 | popularity 4.9 / 5 (17) | comments 0

A team of pioneering South Korean scientists have succeeded in producing the polymers used for everyday plastics through bioengineering, rather than through the use of fossil fuel based chemicals. This groundbreaking research, ...


Acute stress leaves epigenetic marks on the hippocampus

Medicine & Health / Psychology & Psychiatry

created Nov 24, 2009 | popularity 4.6 / 5 (8) | comments 0

(PhysOrg.com) -- Scientists are learning that the dynamic regulation of genes -- as much as the genes themselves -- shapes the fate of organisms. Now the discovery of a new epigenetic mechanism regulating genes in the brain ...


Probing life's extremes in Yellowstone

Probing life's extremes in Yellowstone (w/ Podcast)

Biology / Cell & Microbiology

created Nov 24, 2009 | popularity not rated yet | comments 0

(PhysOrg.com) -- Idaho National Laboratory biologist Frank Roberto squats on a bare, gravelly patch of ground in Yellowstone National Park's rolling backcountry. At his feet, scalding water churns in a mustard-yellow ...


Scientists find emotion-like behaviors, regulated by dopamine, in fruit flies

Medicine & Health / Neuroscience

created Nov 25, 2009 | popularity 5 / 5 (3) | comments 1

Scientists at the California Institute of Technology have uncovered evidence of a primitive emotion-like behavior in the fruit fly, Drosophila melanogaster. Their findings, which may be relevant to the relationship betwee ...


Research sheds light on workings of anti-cancer drug

Chemistry / Analytical Chemistry

created Nov 26, 2009 | popularity not rated yet | comments 0

(PhysOrg.com) -- The copper sequestering drug tetrathiomolybdate (TM) has been shown in studies to be effective in the treatment of Wilson disease, a disease caused by an overload of copper, and certain metastatic cancers. ...



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