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  2. Prokaryote - Wikipedia

    en.wikipedia.org/wiki/Prokaryote

    Eukaryotic cells are some 10,000 times larger than prokaryotic cells by volume, have their DNA organised in a nucleus, and contain membrane-bound organelles. The division between prokaryotes and eukaryotes has been considered the most important distinction or difference among organisms.

  3. Wikipedia:Featured picture candidates/Image:Prokaryote cell ...

    en.wikipedia.org/wiki/Wikipedia:Featured_picture...

    Page 63 describes the inner cytoplasmic membrane, bounded by the peptidoglycan cell wall, which in turn is surrounded by the outer membrane in Gram-negative bacteria. Gram-positive bacteria do not have an outer membrane. Note also that the cell wall is not a rigid structure in either plants or bacteria. If cell walls were truly rigid, plants ...

  4. Bacterial cell structure - Wikipedia

    en.wikipedia.org/wiki/Bacterial_cell_structure

    The cell envelope is composed of the cell membrane and the cell wall. As in other organisms, the bacterial cell wall provides structural integrity to the cell. In prokaryotes , the primary function of the cell wall is to protect the cell from internal turgor pressure caused by the much higher concentrations of proteins and other molecules ...

  5. Nuclear envelope - Wikipedia

    en.wikipedia.org/wiki/Nuclear_envelope

    The nuclear envelope, also known as the nuclear membrane, [1] [a] is made up of two lipid bilayer membranes that in eukaryotic cells surround the nucleus, which encloses the genetic material. The nuclear envelope consists of two lipid bilayer membranes: an inner nuclear membrane and an outer nuclear membrane. [ 4 ]

  6. Cell biology - Wikipedia

    en.wikipedia.org/wiki/Cell_biology

    A drawing of a prokaryotic cell. There are two fundamental classifications of cells: prokaryotic and eukaryotic. Prokaryotic cells are distinguished from eukaryotic cells by the absence of a cell nucleus or other membrane-bound organelle. [10] Prokaryotic cells are much smaller than eukaryotic cells, making them the smallest form of life. [11]

  7. Unicellular organism - Wikipedia

    en.wikipedia.org/wiki/Unicellular_organism

    Eukaryotic cells contain membrane bound organelles. Some examples include mitochondria, a nucleus, or the Golgi apparatus. Prokaryotic cells probably transitioned into eukaryotic cells between 2.0 and 1.4 billion years ago. [31] This was an important step in evolution. In contrast to prokaryotes, eukaryotes reproduce by using mitosis and meiosis.

  8. Cell membrane - Wikipedia

    en.wikipedia.org/wiki/Cell_membrane

    Illustration of a eukaryotic cell membrane Comparison of a eukaryotic vs. a prokaryotic cell membrane. The cell membrane (also known as the plasma membrane or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the interior of a cell from the outside environment (the extracellular space).

  9. Organelle - Wikipedia

    en.wikipedia.org/wiki/Organelle

    Eukaryotic cells are structurally complex, and by definition are organized, in part, by interior compartments that are themselves enclosed by lipid membranes that resemble the outermost cell membrane. The larger organelles, such as the nucleus and vacuoles, are easily visible with the light microscope.