In 1658, Jessner observed the structure of proteases and gave the first idea about cells. He named it Foraminifera. In 1665, Robert Hooke, an engineer of the British Royal Society of London, observed that a wooden ship was stationary but floated in water. A thin section of the shell was observed under a self-made microscope with 30x magnification and he saw numerous tiny honeycomb-like cells or cells. He saw that these kuthuris were like small cells or ivashas for the accommodation of monks or priests of ashrams and inmates of jails. So he named these tiny cells cells. He published all the observed information in the book called Micrographia. The discovery of the cell marked the beginning of cytology. Today it is known as cell biology or molecular biology.
In 1674 Dutch scientist Antonie Van Leeuwenhoek first observed protozoa, bacteria, red blood cells, sperm etc. Important information about the cell was provided by – Grew (1682), Wolff (1759), De Mirbel (1802), Ocken (1805), Lamarck (1809) and Drochet (1824).
In 1825, French scientist Francis Rashpal said that all cells are created from pre-existing cells. In 2019, American scientist William Kalin and his colleagues discovered a mechanism for sensing and adapting cells to oxygen abundance. In 1931, German scientists Max Knol and Ernst Ruska noted the microscopic structure of cells and organelles. Scientists believe that cells appeared 3.5 billion years ago.