Robert Hooke looked through a primitive microscope at a thinly cut piece of cork. He saw a series of walled boxes that reminded him of the tiny rooms, or cellula, occupied by monks.
All organisms are composed of one or more cells. The cell is the basic unit of structure and organization in organisms. All cells come from pre-existing cells. And Anton Van Leeuwenhoek made his version of the microscope and discovered something very odd when he looked a the gunk on his teeth.
