Cells were first discovered by Robert Hook in 1665. He observed the cells in a cork slice with the help of a primitive microscopic. Later in the year 1674 Leeuwenhoek discovered the free living cells in pond water for the first time. In the year 1831 Robert brown discovered the nucleus of the cell. In 1839 Purkinje coined the term protoplasm for the fluid sustance present inside the cell. Later two biologist Schleiden and Schwann presented a theory on cells known as cell theory which states that all the plants and animals are composed of cells and the cells are the basic unit of life. The cell theory was further explained by Virchow in 1855, He suggested that all the cells arise from pre-existing cells. With the discovery of the electron microscope it was possible to observe and understand the complex structure of cell and its various organelles.
“Cells are the structural as well as the fundamental unit of life”