The first episode explores how centuries of scientific and religious dogma were overturned by the earliest discoveries of the existence of cells, and how scientists came to realise that there was, literally, more to life than meets the eye. This three part series tells the extraordinary story of the scientific quest to discover the secrets of the cell and of life itself. Every living thing is made of cells, microscopic building blocks of almost unimaginable power and complexity. The cell is the functional basic unit of life. It was discovered by Robert Hooke and is the functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life.
In 1835, before the final cell theory was developed, Jan Evangelista Purkyn observed small "granules" while looking at the plant tissue through a microscope. Cell theory, first developed in 1839 by Matthias Schleiden and Theodor Schwann, states that all organisms are composed of one or more cells, that all cells come from preexisting cells, that vital functions of an organism occur within cells, and that all cells contain the hereditary information necessary for regulating functions and for transmitting information to the next generation of cells.
BBC Four 2009