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: -In 1855, at the age of 34, he published his now famous aphorism “omnis cellula e cellula” (“every cell stems from another cell”). With this approach Virchow launched the field of cellular pathology. He stated that all diseases involve changes in normal cells, that is, all pathology ultimately is cellular pathology.

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 1838, Rudolf Virchow proposed that ‘Omnis cellula e cellula’ which means that new cells develop from the pre-existing cell by division. The discovery of Rudolf Virchow has modified the cell theory because, before the Rudolf Virchow discovery, Schleiden thought that the new cell gets bud off from the nucleus.

Detailed explanation-5: -2: (a) Rudolf Virchow (1821–1902) popularized the cell theory in an 1855 essay entitled “Cellular Pathology.” (b) The idea that all cells originate from other cells was first published in 1852 by his contemporary and former colleague Robert Remak (1815–1865).