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  2. Life - Wikipedia

    en.wikipedia.org/wiki/Life

    Life is a quality that distinguishes matter that has biological processes, such as signaling and self-sustaining processes, from matter that does not. It is defined descriptively by the capacity for homeostasis, organisation, metabolism, growth, adaptation, response to stimuli, and reproduction.

  3. Biological organisation - Wikipedia

    en.wikipedia.org/wiki/Biological_organisation

    The biological organisation of life is a fundamental premise for numerous areas of scientific research, particularly in the medical sciences. Without this necessary degree of organisation, it would be much more difficult—and likely impossible—to apply the study of the effects of various physical and chemical phenomena to diseases and ...

  4. Cell (biology) - Wikipedia

    en.wikipedia.org/wiki/Cell_(biology)

    Structure of a typical prokaryotic cell. Prokaryotes include bacteria and archaea, two of the three domains of life. Prokaryotic cells were the first form of life on Earth, characterized by having vital biological processes including cell signaling. They are simpler and smaller than eukaryotic cells, and lack a nucleus, and other membrane-bound ...

  5. Biology - Wikipedia

    en.wikipedia.org/wiki/Biology

    Life arose from the Earth's first ocean, which formed some 3.8 billion years ago. [33] Since then, water continues to be the most abundant molecule in every organism. Water is important to life because it is an effective solvent, capable of dissolving solutes such as sodium and chloride ions or other small molecules to form an aqueous solution.

  6. Cell theory - Wikipedia

    en.wikipedia.org/wiki/Cell_theory

    This was a major advance in the field of biology since little was known about animal structure up to this point compared to plants. From these conclusions about plants and animals, two of the three tenets of cell theory were postulated. 1. All living organisms are composed of one or more cells 2. The cell is the most basic unit of life

  7. Morphology (biology) - Wikipedia

    en.wikipedia.org/wiki/Morphology_(biology)

    The etymology of the word "morphology" is from the Ancient Greek μορφή (morphḗ), meaning "form", and λόγος (lógos), meaning "word, study, research". [2] [3]While the concept of form in biology, opposed to function, dates back to Aristotle (see Aristotle's biology), the field of morphology was developed by Johann Wolfgang von Goethe (1790) and independently by the German anatomist ...

  8. Domain (biology) - Wikipedia

    en.wikipedia.org/wiki/Domain_(biology)

    Life is divided into domains, which are subdivided into further groups. Intermediate minor rankings are not shown. Intermediate minor rankings are not shown. In biological taxonomy , a domain ( / d ə ˈ m eɪ n / or / d oʊ ˈ m eɪ n / ) ( Latin : regio [ 1 ] ), also dominion , [ 2 ] superkingdom , realm , or empire , is the highest taxonomic ...

  9. Timeline of the evolutionary history of life - Wikipedia

    en.wikipedia.org/wiki/Timeline_of_the...

    The earliest evidence for life on Earth includes: 3.8 billion-year-old biogenic hematite in a banded iron formation of the Nuvvuagittuq Greenstone Belt in Canada; [30] graphite in 3.7 billion-year-old metasedimentary rocks in western Greenland; [31] and microbial mat fossils in 3.48 billion-year-old sandstone in Western Australia.