AP BIOLOGY

Detailed explanation-1: -The third part, which asserts that cells come from preexisting cells that have multiplied, was described by Rudolf Virchow in 1858, when he stated omnis cellula e cellula (all cells come from cells).

Detailed explanation-2: -Virchow’s theory stated that just as animals are unable to arise without previously existing animals, cells are unable to arise without previously existing cells. The idea that new cells arose from pre-existing cells in both diseased and healthy tissue was not original.

Detailed explanation-3: -Credit for developing cell theory is usually given to three scientists: Theodor Schwann, Matthias Jakob Schleiden, and Rudolf Virchow. In 1839, Schwann and Schleiden suggested that cells were the basic unit of life. Their theory accepted the first two tenets of modern cell theory (see next section, below).

Detailed explanation-4: -In 1855 Virchow published a statement based on his observations Omnis cellula e cellula, which means that all cells arise from pre-existing cells. This was not a new theory.

Detailed explanation-5: -In 1858 he published Cellular Pathology, a groundbreaking book of 20 lectures he had given at the university, which laid the foundations of modern pathology and indeed of modern medical theory. Simply put, Virchow established that all diseases can be traced to cells.