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 greatest accomplishment was his observation that a whole organism does not get sick-only certain cells or groups of cells. In 1855, at the age of 34, he published his now famous aphorism “omnis cellula e cellula” (“every cell stems from another cell”).

Detailed explanation-3: -Cells arise from the pre-existing cells is the second postulate of cell theory. Rudolf Virchow proposed this.

Detailed explanation-4: -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).