Title: Timeline of biology and organic chemistry
Content:  Rudolf Virchow proposed that cells can only arise from pre-existing cells; "Omnis cellula e celulla," all cell from cells. The Cell Theory states that all organisms are composed of cells (Schleiden and Schwann), and cells can only come from other cells (Virchow). ; 1864 – Louis Pasteur disproved the spontaneous generation of cellular life. ; 1865 – Gregor Mendel demonstrated in pea plants that inheritance follows definite rules. The Principle of Segregation states that each organism has two genes per trait, which segregate when the organism makes eggs or sperm. The Principle of Independent Assortment states that each gene in a pair is distributed 
Title: Cell theory
Content:  Virchow, and Albert Kolliker. In 1855, Rudolf Virchow added the third tenet to cell theory. In Latin, this tenet states Omnis cellula e cellula. This translated to:  However, the idea that all cells come from pre-existing cells had in fact already been proposed by Robert Remak; it has been suggested that Virchow plagiarized Remak and did not give him credit. Remak published observations in 1852 on cell division, claiming Schleiden and Schawnn were incorrect about generation schemes. He instead said that binary fission, which was first introduced by Dumortier, was how reproduction of new animal cells were made. Once this tenet was added, the classical cell theory was complete.
Title: Cell (biology)
Content: 1632–1723: Antonie van Leeuwenhoek taught himself to make lenses, constructed basic optical microscopes and drew protozoa, such as Vorticella from rain water, and bacteria from his own mouth. ; 1665: Robert Hooke discovered cells in cork, then in living plant tissue using an early compound microscope. He coined the term cell (from Latin cellula, meaning "small room" ) in his book Micrographia (1665). ; 1839: Theodor Schwann and Matthias Jakob Schleiden elucidated the principle that plants and animals are made of cells, concluding that cells are a common unit of structure and development, and thus founding the cell theory. ; 1855: Rudolf Virchow stated that new cells come from 
Title: Rudolf Virchow
Content:  physiological and pathological". Virchow dedicated his magnum opus Die Cellularpathologie to Goodsir. Virchow's cellular theory was encapsulated in the epigram Omnis cellula e cellula ("all cells (come) from cells"), which he published in 1855. (The epigram was actually coined by François-Vincent Raspail, but popularized by Virchow.) It is a rejection of the concept of spontaneous generation, which held that organisms could arise from nonliving matter. For example, maggots were believed to appear spontaneously in decaying meat; Francesco Redi carried out experiments that disproved this notion and coined the maxim Omne vivum ex ovo ("Every living thing comes from a living thing" — literally "from an egg"); Virchow (and his predecessors) extended this to state that the only source for a living cell was another living cell.
Title: Rudolf Virchow
Content:   Virchow is credited with several key discoveries. His most widely known scientific contribution is his cell theory, which built on the work of Theodor Schwann. He was one of the first to accept the work of Robert Remak, who showed that the origin of cells was the division of pre-existing cells. He did not initially accept the evidence for cell division and believed that it occurs only in certain types of cells. When it dawned on him in 1855 that Remak might be right, he published Remak's work as his own, causing a falling-out between the two. Virchow was particularly influenced in cellular theory by the work of John Goodsir of Edinburgh, whom he described as "one of the earliest and most acute observers of cell-life 
Title: Cell theory
Content:  and existence of cells in animals or plants. This conclusion was not made until Henri Dutrochet. Besides stating “the cell is the fundamental element of organization”, Dutrochet also claimed that cells were not just a structural unit, but also a physiological unit. In 1804, Karl Rudolphi and J.H.F. Link were awarded the prize for "solving the problem of the nature of cells", meaning they were the first to prove that cells had independent cell walls by the Königliche Societät der Wissenschaft (Royal Society of Science), Göttingen. Before, it had been thought that cells shared walls and the fluid passed between them this way.
Title: Cell (biology)
Content:  cells by cell division (omnis cellula ex cellula). ; 1859: The belief that life forms can occur spontaneously (generatio spontanea) was contradicted by Louis Pasteur (1822–1895) (although Francesco Redi had performed an experiment in 1668 that suggested the same conclusion). ; 1931: Ernst Ruska built the first transmission electron microscope (TEM) at the University of Berlin. By 1935, he had built an EM with twice the resolution of a light microscope, revealing previously unresolvable organelles. ; 1953: Based on Rosalind Franklin's work, Watson and Crick made their first announcement on the double helix structure of DNA. ; 1981: Lynn Margulis published Symbiosis in Cell Evolution detailing the endosymbiotic theory. 
Title: Cell biology
Content:  Cells were first seen in 17th century Europe with the invention of the compound microscope. In 1665, Robert Hooke termed the building block of all living organisms as "cells" (published in Micrographia) after looking at a piece of cork and observing a cell-like structure, however, the cells were dead and gave no indication to the actual overall components of a cell. A few years later, in 1674, Anton Van Leeuwenhoek was the first to analyze live cells in his examination of algae. All of this preceded the cell theory which states that all living things are made up of cells and that cells are the functional and structural unit of organisms. This was ultimately concluded by plant scientist, Matthias Schleiden and animal scientist Theodor Schwann in 1838, who viewed live cells in plant and animal tissue, respectively. 19 years later, Rudolf Virchow further contributed to the cell theory, adding that all cells come from the division of pre-existing cells. Viruses are not considered in cell biology – they lack the characteristics of a living cell, and instead are studied in the microbiology subclass of virology.
Title: History of zoology (1859–present)
Content:   Cell theory led zoologists to re-envision individual organisms as interdependent assemblages of individual cells. Scientists in the rising field of cytology, armed with increasingly powerful microscopes and new staining methods, soon found that even single cells were far more complex than the homogeneous fluid-filled chambers described by earlier microscopists. Much of the research on cell reproduction came together in August Weismann's theory of heredity: he identified the nucleus (in particular chromosomes) as the hereditary material, proposed the distinction between somatic cells and germ cells (arguing that chromosome number must be halved for germ cells, a precursor to the concept of meiosis), and adopted Hugo de Vries's theory of pangenes. Weismannism was extremely influential, especially in the new field of experimental embryology. By the 1880s, bacteriology was becoming a coherent discipline, especially through the work of Robert Koch, who introduced methods for growing pure cultures on agar gels containing specific nutrients in Petri dishes. The long-held idea that living organisms could easily originate from nonliving matter (spontaneous generation) was attacked in a series of experiments carried out by Louis Pasteur, while debates over vitalism vs. mechanism (a perennial issue since the time of Aristotle and the Greek atomists) continued apace.
Title: Cell theory
Content: 1. All living organisms are composed of one or more cells ; 2. The cell is the most basic unit of life 3. All cells arise only from pre-existing cells Credit for developing cell theory is usually given to two scientists: Theodor Schwann and Matthias Jakob Schleiden. While Rudolf Virchow contributed to the theory, he is not as credited for his attributions toward it. In 1839, Schleiden suggested that every structural part of a plant was made up of cells or the result of cells. He also suggested that cells were made by a crystallization process either within other cells or from the outside. However, this was not an 

Question: who proved that cells come from other cells?
Answer: Matthias Schleiden.
Robert Hooke.
Robert Remak.
Theodor Schwann.
Rudolf Virchow.