A cell may be defined as the ‘structural and functional unit of a living being. It is the minimal biological unit capable of maintaining and propagating itself.
The study of cell comes under the preview of cytology, physiology and anatomy; while anatomy deals mainly with the structural aspects, the other two lay emphasis both on structure and function.
The word cell has been derived from the Latin word cellula meaning a small compartment. The term in the present sense was first used by Robert Hooke (1665) in his book Micrographic.
There has been some mention about cell in ancient Indian literature also. Parasara (1st century BC) in his book Vrkshayurveda refers to invisible compartments in the leaf and names them Rasakosha. He further opines that each cell has a sap (Rasa), not visible to the naked eye (Anavah) and has two boundaries (Kalavestitena), some of the cells have a coloring matter (Ranjakayukta).
The credit however of discovering the cell goes to Robert Hooke (1965), since it s difficult to establish the discovery to the ancient Indians in the absence of complete text of Parasara and the general apathy among Indians to their scientific heritage.
Robert Hooke who constructed the first compound microscope observed the sections of cork and opined that they contain honey comb like compartments. German Biologists M.J. Schleiden and T.S. Schwann (1838) established the ‘cell theory’ that all organisms are made up of cells.
Dutrochet in 1824 separated the cells from Mimosa plant. He boiled the leaves in nitric acid to isolate the cells. Turpin and Meyers (1830) observed that every tissue is an assemblage of cells.
One of the significant discoveries of the cell came from Robert Brown (1830). He discovered the presence of a spherical body in the centre of every cell, which he named ‘nucleus’
In the year 1835-37, Purkinje and Mohi independently discovered that protoplasm is an important constituent of every cell and it plays an important role in every cell activity including division. Golgi (1838) discovered the golgi apparatus. Balbiani (1881) discovered chromosomes in the salivary glands of Chironomus. At about the same time, Flemming (1882) studied cell division in detail and gave the name Mitosis.
Endoplasmic reticulum was discovered by Porter in 1945, while Benda gave the name mitochondria to organelles originally discovered by Hemming. Lysosomes were discovered in 1955 by de Duve.