write the short notes on cell
Answers
Answer:
Cell is the basic unit of life in which all the fundamental functions of living organism are marked. Cell was discovered by Robert Hooke (1665). He coined the term cell (Gk. Kytos- cell, Lt. cella-hollow space) and described it in his book Micrographia. Purkinje (1839) named the jelly-like substance of the cell as protoplasm and Robert Brown (1831) discovered the nucleus. J. Huxley termed protoplasm as ‘physical basis of life’.
M.J. Schleiden (1838) working on plant cell and T. Schwann (1839) working on animal cell established the cell theory which states that all organisms are made upon of cells and cell is the unit of structure and function of all living organisms. Rudolf Virchow (1855) postulated ‘Omnis cellula those cellula’ which means all cells arise from pre-existing cells. However, there are some exceptions to cell theory-viruses lack protoplasm, bacteria and cyanobacteria (blue-green algae- BGA) lack well organized nucleus, etc.
Cell is self-contained unit. It lives independently in unicellular organisms but shows divisions of labour in multicellular organisms. All cells are totipotent as they are capable of regenerating a whole plant.
Answer:
cell is the smallest unit of any organism.it is of two types
1.pokaryotic
2.meristematic