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Terrestrial Life, Microorganism, Plant (Flower, Tree), Animal


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life : an organismic state characterized by capacity for metabolism, growth, reaction to stimuli, and reproduction — Webster

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Life is a characteristic distinguishing physical entities having biological processes, such as signaling and self-sustaining processes, from those that do not, either because such functions have ceased, or because they never had such functions and are classified as inanimate. Various forms of life exist, such as plants, animals, fungi, protists, archaea, and bacteria. The criteria can at times be ambiguous and may or may not define viruses, viroids, or potential artificial life as “living”. Biology is the primary science concerned with the study of life, although many other sciences are involved.

The definition of life is controversial. The current definition is that organisms maintain homeostasis, are composed of cells, undergo metabolism, can grow, adapt to their environment, respond to stimuli, and reproduce. However, many other biological definitions have been proposed, and there are some borderline cases of life, such as viruses. Throughout history, there have been many attempts to define what is meant by “life” and many theories on the properties and emergence of living things, such as materialism, the belief that everything is made out of matter and that life is merely a complex form of it; hylomorphism, the belief that all things are a combination of matter and form, and the form of a living thing is its soul; spontaneous generation, the belief that life repeatedly emerges from non-life; and vitalism, a now largely discredited hypothesis that living organisms possess a “life force” or “vital spark”. Modern definitions are more complex, with input from a diversity of scientific disciplines. Biophysicists have proposed many definitions based on chemical systems; there are also some living systems theories, such as the Gaia hypothesis, the idea that the Earth itself is alive. Another theory is that life is the property of ecological systems, and yet another is elaborated in complex systems biology, a branch or subfield of mathematical biology. Abiogenesis describes the natural process of life arising from non-living matter, such as simple organic compounds. Properties common to all organisms include the need for certain core chemical elements to sustain biochemical functions. — Wikipedia

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AAAS EurekAlert! – Life, NPR Archives







EurekAlert! - Biology The premier online source for science news since 1996. A service of the American Association for the Advancement of Science.

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    (University of Leicester) Palaeontologists investigate the macabre science behind how animals decay and fossilize. […]

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    on March 21, 2018 at 4:00 am

    (University of Waterloo) Technology developed at the University of Waterloo reliably and affordably increases the efficiency of internal combustion engines by more than 10 per cent. […]

  • 'Wiggling and jiggling': Study explains how...
    on March 21, 2018 at 4:00 am

    (University of Bristol) The brilliant physicist Richard Feynman famously said that, in principle, biology can be explained by understanding the wiggling and jiggling of atoms. For the first time, new research from the University of Bristol, UK and the University of Waikoto, New Zealand explains how this 'wiggling and jiggling' of the atoms in enzymes -- the proteins that make biological reactions happen -- is 'choreographed' to make them work at a particular temperature. […]

  • Fixing soybean's need for nitrogen
    on March 21, 2018 at 4:00 am

    (American Society of Agronomy) To make protein, soybean plants need a lot of nitrogen.Beneficial bacteria in root nodules typically assist. A new study shows it's possible to increase the number of soybean root nodules--and the bacteria that live there--to further increase crop yields. This could remove the need to apply additional nitrogen fertilizers. […]

  • Hunting squid slowed by rising carbon levels
    on March 21, 2018 at 4:00 am

    (James Cook University) James Cook University scientists in Australia have found high carbon dioxide levels cause squid to bungle attacks on their prey. […]