What (who) is cells - definition
![Staining of a ''[[Caenorhabditis elegans]]'' highlights the nuclei of its cells.](https://commons.wikimedia.org/wiki/Special:FilePath/C elegans stained.jpg?width=200 "Staining of a ''[[Caenorhabditis elegans]]'' highlights the nuclei of its cells.")
![An outline of the [[catabolism]] of [[protein]]s, [[carbohydrate]]s and [[fat]]s](https://commons.wikimedia.org/wiki/Special:FilePath/Catabolism schematic.svg?width=200 "An outline of the [[catabolism]] of [[protein]]s, [[carbohydrate]]s and [[fat]]s")
![A fluorescent image of an endothelial cell. Nuclei are stained blue, [[mitochondria]] are stained red, and microfilaments are stained green.](https://commons.wikimedia.org/wiki/Special:FilePath/DAPIMitoTrackerRedAlexaFluor488BPAE.jpg?width=200 "A fluorescent image of an endothelial cell. Nuclei are stained blue, [[mitochondria]] are stained red, and microfilaments are stained green."){kind=tracking}
![Deoxyribonucleic acid]] (DNA)](https://commons.wikimedia.org/wiki/Special:FilePath/DNA orbit animated.gif?width=200 "Deoxyribonucleic acid]] (DNA)")
![Diagram of the [[endomembrane system]]](https://commons.wikimedia.org/wiki/Special:FilePath/Endomembrane system diagram en.svg?width=200 "Diagram of the [[endomembrane system]]")
![Human cancer cells, specifically [[HeLa cells]], with DNA stained blue. The central and rightmost cell are in [[interphase]], so their DNA is diffuse and the entire nuclei are labelled. The cell on the left is going through [[mitosis]] and its chromosomes have condensed.](https://commons.wikimedia.org/wiki/Special:FilePath/HeLa cells stained with Hoechst 33258.jpg?width=200 "Human cancer cells, specifically [[HeLa cells]], with DNA stained blue. The central and rightmost cell are in [[interphase]], so their DNA is diffuse and the entire nuclei are labelled. The cell on the left is going through [[mitosis]] and its chromosomes have condensed.")
![Structure of a typical [[plant cell]]](https://commons.wikimedia.org/wiki/Special:FilePath/Plant cell structure-en.svg?width=200 "Structure of a typical [[plant cell]]")
![Structure of a typical [[prokaryotic]] cell](https://commons.wikimedia.org/wiki/Special:FilePath/Prokaryote cell.svg?width=200 "Structure of a typical [[prokaryotic]] cell")
![tRNA]]. Newly synthesized proteins (''black'') are often further modified, such as by binding to an effector molecule (''orange''), to become fully active.](https://commons.wikimedia.org/wiki/Special:FilePath/Proteinsynthesis.png?width=200 "tRNA]]. Newly synthesized proteins (''black'') are often further modified, such as by binding to an effector molecule (''orange''), to become fully active.")
![cork]], 1665](https://commons.wikimedia.org/wiki/Special:FilePath/RobertHookeMicrographia1665.jpg?width=200 "cork]], 1665")
![Glacier National Park]] in the United States.](https://commons.wikimedia.org/wiki/Special:FilePath/Stromatolites.jpg?width=200 "Glacier National Park]] in the United States.")
![[[Prokaryotes]] divide by [[binary fission]], while [[eukaryotes]] divide by [[mitosis]] or [[meiosis]].](https://commons.wikimedia.org/wiki/Special:FilePath/Three cell growth types.svg?width=200 "[[Prokaryotes]] divide by [[binary fission]], while [[eukaryotes]] divide by [[mitosis]] or [[meiosis]].")
The cell (from the Latin word cellula meaning 'small room') is the basic structural and functional unit of life forms. Every cell consists of a cytoplasm enclosed within a membrane, which contains many biomolecules such as proteins and nucleic acids.
Cells can acquire specified function and carry out various tasks within the cell such as replication, DNA repair, protein synthesis, and motility. Cells are capable of specialization and mobility within the cell. Most cells are measured in micrometers due to their small size.
Most plant and animal cells are only visible under a light microscope, with dimensions between 1 and 100 micrometres. Electron microscopy gives a much higher resolution showing greatly detailed cell structure. Organisms can be classified as unicellular (consisting of a single cell such as bacteria) or multicellular (including plants and animals). Most unicellular organisms are classed as microorganisms. The number of cells in plants and animals varies from species to species; it has been approximated that the human body contains an estimated 37 trillion (3.72×1013) cells. The brain accounts for around 80 billion of these cells.
The study of cells and how they work has led to many other studies in related areas of biology, including: discovery of DNA, cancer systems biology, aging and developmental biology.
Cell biology is the study of cells, which were discovered by Robert Hooke in 1665, who named them for their resemblance to cells inhabited by Christian monks in a monastery. Cell theory, first developed in 1839 by Matthias Jakob Schleiden and Theodor Schwann, states that all organisms are composed of one or more cells, that cells are the fundamental unit of structure and function in all living organisms, and that all cells come from pre-existing cells. Cells emerged on Earth about 4 billion years ago.
Wikipedia
Cell most often refers to:
- Cell (biology), the functional basic unit of life
Cell may also refer to:
