|♦ Discovery of Cells
• First cell discovered by Robert Hoke In 1665.
• Robert Hooke examined a piece of Cork under microscope and founf honey like shapes.
• He gave Cell term to those honey like shapes.
• Cell is a Latin Word , it means Hollow Space/Little Room.
• Robert Hooke actually discovered Suberised Cell Wall or dead cell ,not the living cell.
• Robert Hooke published his observation in his book “Micrographia” in 1665.
• He was First to Use term Cell. and known as Father of Cytology.
• Antoni Vonn Leeuwenhoeck in 1676 first time noticed a free living cell.
• This living cell was a Bacteria discovered from the rain water of soil.
• He named it Wild Animalcules.
♦ Cell Theory
• Cell theory given by :- Schleiden (German Botanist) & Schwann (British Zoologist)
• In 1838 They observed a large number of plants and observed that all plants are composed of different kinds of cells which form the tissues of the plant.
• Idea of cell theory given by :- French scientist Dutrochaete.
• Cell Theory was extended by :- Rudolf Virchow.
• He first time indicate that tissues are made by the Union of cells.
•Modern cell theory is called cell principle.
• According to it ……
Cell is the structural and Functional unit of life.
Cell is the smallest unit in which life can exist.
All living being were composed of cell.
Each cell consists of a Protoplasmic mass, containing a nucleus.
• Rudolf Virchow suggested that “All Living cells arise from pre existing living cells.”
• It is called Law of Cell Lineage.
• This fact experimentally proved by Louis Pasteur.
• Louis Pasteur performed Swan Neck flask experiment.
• Louis Pasteur conducted Broth experiments that rejected the idea of spontaneous generation even for Microbes.
• Rudolf Virchow (1855) first explained that cells divided and new cells are formed from pre-existing cells (Omnis cellula-e cellula).
• He modified the hypothesis of Schleiden and Schwann to give the cell theory a final shape.
• Cell theory as understood today is ……
◘ all living organisms are composed of cells and products of cells.
◘ all cells arise from pre-existing cells