<Tr> <Th> FMA </Th> <Td> 68646 </Td> </Tr> <Tr> <Td_colspan="2"> Anatomical terminology (edit on Wikidata) </Td> </Tr> <P> The cell (from Latin cella, meaning "small room") is the basic structural, functional, and biological unit of all known living organisms . A cell is the smallest unit of life . Cells are often called the "building blocks of life". The study of cells is called cell biology . </P> <P> Cells consist of cytoplasm enclosed within a membrane, which contains many biomolecules such as proteins and nucleic acids . Organisms can be classified as unicellular (consisting of a single cell; including bacteria) or multicellular (including plants and animals). While the number of cells in plants and animals varies from species to species, humans contain more than 10 trillion (10) cells . Most plant and animal cells are visible only under a microscope, with dimensions between 1 and 100 micrometres . </P>

Why cells are called basic unit of life
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