Cell : The Unit of Life

Cell theory

  • Cell is the structural and functional unit of all living things.
  • Robert hooke (1665) used crude microscope and discovered hollow cavities (empty boxes) like compartments in a very thin slice of cork (cell wall) and named them as cellular (or) cells.
  • A living cell was first described by Anton Von Leeuwenhoek.
  • Robert Brown Laher named and discovered the nucleus in a cell.
  • The term protoplasm was coined by J.E.Purkinje. Protoplasm is the living substance present inside the cell.
  • Electron microscope was developed by Max knoll and Ernst Ruska (1931) in Germany.
  • Study of living cells can't be done by electron microscope because of high voltage (50,000 - 1,00,000 Volts), which is required to operate is, as that can kill the living materials.
  • German Botanist M.J. schleiden (1838) and a British zoologist T. Schwann (1839) gave the concept "all living organisms are composed of cells" and products of cells.
  • The theory given by schleiden and Schwann did not explain how new cells were formed.
  • Rudolf Virchow (1855) first explained that cells divide and new cells are formed from pre existing cells (Omnis cellula-e cellula).
  • Viruses, Viroids and prions are exceptions to the cell theory as they are obligate parasites (sub cellular in nature).
  • Cell wall, cell - discovered by Robert Hooke (Non Living). Living cell - A.V. Leeuwenhoek.
  • To remember botanist & zoologist, swans are bird which are under animal kingdom, so, schwann was zoologist.

View this video for the topic from 1:00 to 8:51


Disclaimer: Compete.etutor.co may from time to time provide links to third party Internet sites under their respective fair use policy and it may from time to time provide materials from such third parties on this website. These third party sites and any third party materials are provided for viewers convenience and for non-commercial educational purpose only. Compete does not operate or control in any respect any information, products or services available on these third party sites. Compete.etutor.co makes no representations whatsoever concerning the content of these sites and the fact that compete.etutor.co has provided a link to such sites is NOT an endorsement, authorization, sponsorship, or affiliation by compete.etutor.co with respect to such sites, its services, the products displayed, its owners, or its providers.