<P> Credit for developing cell theory is usually given to two scientists : Theodor Schwann and Matthias Jakob Schleiden . While Rudolf Virchow contributed to the theory , he is not as credited for his attributions toward it . In 1839 , Schleiden suggested that every structural part of a plant was made up of cells or the result of cells . He also suggested that cells were made by a crystallization process either within other cells or from the outside . However , this was not an original idea of Schleiden . He claimed this theory as his own , though Barthelemy Dumortier had stated it years before him . This crystallization process is no longer accepted with modern cell theory . In 1839 , Theodor Schwann states that along with plants , animals are composed of cells or the product of cells in their structures . This was a major advancement in the field of biology since little was known about animal structure up to this point compared to plants . From these conclusions about plants and animals , two of the three tenets of cell theory were postulated . </P>
<P> Credit for developing cell theory is usually given to two scientists : Theodor Schwann and Matthias Jakob Schleiden . While Rudolf Virchow contributed to the theory , he is not as credited for his attributions toward it . In 1839 , Schleiden suggested that every structural part of a plant was made up of cells or the result of cells . He also suggested that cells were made by a crystallization process either within other cells or from the outside . However , this was not an original idea of Schleiden . He claimed this theory as his own , though Barthelemy Dumortier had stated it years before him . This crystallization process is no longer accepted with modern cell theory . In 1839 , Theodor Schwann states that along with plants , animals are composed of cells or the product of cells in their structures . This was a major advancement in the field of biology since little was known about animal structure up to this point compared to plants . From these conclusions about plants and animals , two of the three tenets of cell theory were postulated . </P>
where does the cell theory state that cells come from
where does the cell theory state that cells come from
a crystallization process either within other cells or from the outside
a crystallization process either within other cells or from the outside