HISTORY OF CELL BIOLOGYScientific knowledge grows with the development of new tools and techniques for studying various physical and biological processes. This is true also of the origin of the concept of cell as a basic unit of life. By 1800 A.D., good microscopes were developed and consequently plants and animals were found to be made up of small units, later known as 'cells'. However, it was only in 1838, that the cell theory was proposed. According to this theory, the cell is both the structural and the functional unit of all living organisms. Cell theory gave a great impetus to study of the cell. It was established that the cell is a mass of protoplasm limited by a cell membrane and possessing a nucleus. Another important observation was thatcells come only from pre-existing cells as a result of cell division. Details of cell division were soon worked out. It became apparent that mitosis is the formation of nuclear filaments (chromosomes) and their equal division between the daughter cells..It was also observed that organisms generally develop from the fusion of two sex cells, the spermatozoon (male sex cell) and ovum (female sex cell). In 1892, cytology (cyto = cell, logos = study) was established as a separate branch of biology. Study of cells with, electron microscope gave a new dimension to the study of cell. Detailed morphological studies of the cell helped to relate the structure with furiction of cellular organelles.
Interaction between various branches of scientific enquiry leads to their overall growth. The interaction between cytology and genetics on one hand and between physiology and biochemistry on the other gave rise to a more comprehensive discipline, Cell Biology, which embodies all that should be known about the cell.