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Geosciences LibreTexts

4: Structure of life

  • Page ID
    6191
    • 3.1: Unique Characteristics of Prokaryotic Cells
      Prokaryotic cells differ from eukaryotic cells in that their genetic material is contained in a nucleoid rather than a membrane-bound nucleus. In addition, prokaryotic cells generally lack membrane-bound organelles. Prokaryotic cells of the same species typically share a similar cell morphology and cellular arrangement. Most prokaryotic cells have a cell wall that helps the organism maintain cellular morphology and protects it against changes in osmotic pressure.
    • 3.2: Unique Characteristics of Eukaryotic Cells
      Eukaryotic cells are defined by the presence of a nucleus containing the DNA genome and bound by a nuclear membrane (or nuclear envelope) composed of two lipid bilayers that regulate transport of materials into and out of the nucleus through nuclear pores. Eukaryotic cell morphologies vary greatly and may be maintained by various structures, including the cytoskeleton, the cell membrane, and/or the cell wall The nucleolus in the nucleus of eukaryotic cells is the site of ribosomal synthesis.
    • 3.3: Viruses