A eukaryote is an organism with a complex cell or cells, in which the genetic material is organized into a membrane-bound nucleus or nuclei.
Eukaryotes (also spelled "eucaryotes") comprise animals, plants, and fungi—which are mostly multicellular - as well as various other groups that are collectively classified as protists (many of which are unicellular).
In contrast, prokaryotes are organisms, such as bacteria and archaea, that lack nuclei and other complex cell structures.
Eukaryotes share a common origin, and are often treated formally as a superkingdom, empire, or domain.
In the domain system, eukaryotes have more in common with archaean prokaryotes than bacterial prokaryotes.
Prokaryote Prokaryotes are organisms without a cell nucleus, or indeed any other membrane-bound organelles, in most cases unicellular (in rare cases, ... >
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Organelle In cell biology, an organelle is one of several structures with specialized functions, suspended in the cytoplasm of a eukaryotic cell. Eukaryotes ... >
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Plant cell There are three major classes of plant cells that can then differentiate to form the tissue structures of roots, stems, and leaves. (The three ... >
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Protist Protists are a heterogeneous group of living things, comprising those eukaryotes that are neither animals, plants, nor fungi. They are usually ... >
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Microorganism A microorganism or microbe is an organism that is so small that it is microscopic (invisible to the naked eye). Microorganisms are often illustrated ... >
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Protozoa Protozoa are single-celled eukaryotes (organisms whose cells have nuclei) that commonly show characteristics usually associated with animals, most ... >
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Chloroplast Chloroplasts are organelles found in plant cells and eukaryotic algae that conduct photosynthesis. Chloroplasts absorb sunlight and use it in ... >
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Cell (biology) The cell is the structural and functional unit of all living organisms, and is sometimes called the "building block of life." Some organisms, such as ... >
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Dinoflagellate The dinoflagellates are a large group of flagellate protists. Some species, called zooxanthellae, are endosymbionts of marine animals and protozoa, ... >
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Spore In biology, a spore is a reproductive structure that is adapted for dispersion and surviving for extended periods of time in unfavorable conditions. ... >
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