DISCOVERY OF CELLS AND CELL THEORY Presented by R.Shalini Ist M.Sc Microbiology
Cells Smallest unit of life View under microscope independent existence Cells also contain the body’s hereditary material. Performing the essential functions of life.
Virchow Schwann Schleiden Anton wan leeuwenhoek Robert hooke scientists
Robert Hooke Named as cells Discovered bacteria called Animalcules Leeuwenhoek Matthias schleiden Discovered that all plants are made of cells 1838 Discovered that all animals are made of cells Theodore Schwann 1839 Ruldolf Virchow Discovered that all cells come from other cells that already exist 1858 TIMELINE
Contributions English scientist Coined the term “cell” in 1665 Inventor of compund microscope He found cell in cork Cor cells look like honey comb CELLS DISCOVERY Robert Hooke ( )
cork Oak tree Cork -Honey comb
Dutch scientist Father of ancient microbiology Create lenses to magnify the cells. The magnification ranges from 200x-10,000,000x 1673 discovered little organ in pond of scum Discovered bacteria called Animalcules in 1673 Others cells to be observed RBC, sperm cells, protozoa Anton Van Leeuwenhoek ( )
Compound Microscope observations
Cell theory Matthias Schleiden ( ) German scientist studied plant ctells using compound microscope cell is basic building block of all plant matter 1838-discovered that all plants are made of cells Ruldolf Virchow ( ) German scientist 1858-discovered that all cells come from other cells that already exist Theodore Schwann German scientist 1839-discovered that all animals are made of cells His observations stated into theory : 1. Cells are organisms,it consist of one or more cells. 2. The cell is the basic unit of life
Basic principle of Cell Theory
Modern Cell Theory
Viruses do not possess a cellular machinery. They consist of a nucleic acid (DNA & RNA) core surrounded by a protein sheath and are considered to be an organism. The bodies of certain fungi are made up of protoplasm and nuclei. RBCs and sieve tube cells continue to live without nucleus and other vital organelles. Bacteria and blue-green algae do not have an organised nucleus. Their genetic material (DNA) is naked and the cell organelles are absent Exceptions of cell theory