Cell Nehru Garden Jalandhar

CELL . world is as old as man itself. All The study of living beings in the

the living organisms which we see are essentially complex structures made up of one or more cells. These have same basic cellular structures of organization and perform basic similar physiological functions. Cell is thus the basic unit of life in living being. A cell is the smallest unit of structure and function. It has the capacity of reproduction, mutation and it responds to various stimuli

Discovery of Cell Cell was discovered by Robert Hooke in 1665. He studied a thin piece of cork with his crude microscope. Hooke discribed that the cork is made up of hundreds of little hexagonal boxes giving a kind of honey comb apperance. He called these little boxes cells. In 1674, Antony Van Leeuwenhoek was the first who observed free cells such as bacteris, protozoa, spermatozoa and red blood corpuscles under his own designed simple microscope.The German biologists, M.J. Schleiden and T.Schwann in 1838 and 1839, respectively proposed the cell theory which postulated that cell is the basic unit of sturcture and function of life. The cell theory was refined further in 1855 when another German biologist,R. Virchow presented the idea that all cells arise from pre-existing cells.

PROKARYOTIC AND EUKARYOTIC CELLS 

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The cells, on the basis of their nuclear organizatio have been classified into two types: (a) Prokaryotic cells (b) Eukaryotic cells