Cell theory

Human cancer cells with nuclei (specifically the DNA) stained blue. The central and rightmost cell are in interphase, so the entire nuclei are labeled. The cell on the left is going through mitosis and its DNA has condensed.

In biology, cell theory is a scientific theory first formulated in the mid-nineteenth century, that living organisms are made up of cells, that they are the basic structural/organizational unit of all organisms, and that all cells come from pre-existing cells. Cells are the basic unit of structure in all living organisms and also the basic unit of reproduction.

Cell theory has traditionally been accepted as the governing theory of all life,[1] but some biologists consider non-cellular entities such as viruses living organisms[2] and thus disagree with the universal application of cell theory to all forms of life.

  1. ^ Schaefer, G. Bradley; Thompson, Jr., James N. (2017). "Chapter 1: Genetics: Unity and Diversity". Medical Genetics: An Integrated Approach (Digital). McGraw Hill. ISBN 978-1259095191.
  2. ^ Koonin, Eugene V.; Starokadomskyy, Petro (November 2016). "Are viruses alive? The replicator paradigm sheds decisive light on an old but misguided question". Studies in History and Philosophy of Science Part C: Studies in History and Philosophy of Biological and Biomedical Sciences. 59: 125–134. doi:10.1016/j.shpsc.2016.02.016. PMC 5406846. PMID 26965225.