Question: what is the most fundamental unit of life according to the cell theory?
Answer: cells

In biology , cell theory is the historic scientific theory , now universally accepted , that living organisms are made up of cells . Cells are the basic unit of structure in all organisms and also the basic unit of reproduction . With continual improvements made to microscopes over time , magnification technology advanced enough to discover cells in the 17th century . This discovery is largely attributed to Robert Hooke , and began the scientific study of cells , also known as cell biology . Over a century later , many debates about cells began amongst scientists . Most of these debates involved the nature of cellular regeneration , and the idea of cells as a fundamental unit of life . Cell theory was eventually formulated in 1839 . This is usually credited to Matthias Schleiden and Theodor Schwann . However , many other scientists like Rudolf Virchow contributed to the theory .