All living things are made up of cells. Some organisms, such as bacteria, may exist solely as single-celled creatures. Others, including humans, are comprised of countless cells all working together to form a single living being. Humans are comprised of trillions of cells that are organized into tissues such as muscle and skin or organs like the liver or lung.
Cell Structure | Cellular Components | Cell Division | Cellular Processes | Plasma Membrane | Cellular Organelles | Cytoskeleton | Endoplasmic Reticulum | Mitochondria | Cell Cycle | Cellular Function | Cell Nucleus | Cell Membrane | Cellular Biology | Cytology
American Society for Cell Biology | European Molecular Biology Organization | International Society for Stem Cell Research | the Cell: An Image Library | Microscopy Society of America | Federation of American Societies for Experimental Biology | British Society for Cell Biology | American Society for Biochemistry and Molecular Biology | Cell Press | Society for Experimental Biology and Medicine