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Eukaryotic cells, containing membrane-bound organelles with diverse functions, probably derived from prokaryotes engulfing each other via phagocytosis. (See Symbiogenesis and Endosymbiont ). Bacterial viruses ( bacteriophages ) emerge before or soon after the divergence of the prokaryotic and eukaryotic lineages. [ 44 ]
Leland Harrison "Lee" Hartwell (born October 30, 1939) is an American former president and director of the Fred Hutchinson Cancer Research Center in Seattle, Washington.He shared the 2001 Nobel Prize in Physiology or Medicine with Paul Nurse and Tim Hunt, for their discoveries of protein molecules that control the division (duplication) of cells.
The eukaryotic cell cycle consists of four distinct phases: G 1 phase, S phase (synthesis), G 2 phase (collectively known as interphase) and M phase (mitosis and cytokinesis). M phase is itself composed of two tightly coupled processes: mitosis, in which the cell's nucleus divides, and cytokinesis, in which the cell's cytoplasm and cell membrane divides forming two daughter cells.
The eukaryotic cell seems to have evolved from a symbiotic community of prokaryotic cells. DNA-bearing organelles like mitochondria and chloroplasts are remnants of ancient symbiotic oxygen-breathing bacteria and cyanobacteria, respectively, where at least part of the rest of the cell may have been derived from an ancestral archaean prokaryote ...
Theodor Heinrich Boveri (12 October 1862 – 15 October 1915) was a German zoologist, comparative anatomist and co-founder of modern cytology. [1] He was notable for the first hypothesis regarding cellular processes that cause cancer, and for describing chromatin diminution in nematodes. [2] His brother was industrialist Walter Boveri.
In eukaryotes, the cell cycle consists of four main stages: G 1, during which a cell is metabolically active and continuously grows; S phase, during which DNA replication takes place; G 2, during which cell growth continues and the cell synthesizes various proteins in preparation for division; and the M phase, during which the duplicated ...
Edward Hitchcock's fold-out paleontological chart in his 1840 Elementary Geology. Although tree-like diagrams have long been used to organise knowledge, and although branching diagrams known as claves ("keys") were omnipresent in eighteenth-century natural history, it appears that the earliest tree diagram of natural order was the 1801 "Arbre botanique" (Botanical Tree) of the French ...
1869: Friedrich Miescher discovers a weak acid in the nuclei of white blood cells that today we call DNA. In 1871 he isolated cell nuclei, separated the nucleic cells from bandages and then treated them with pepsin (an enzyme which breaks down proteins). From this, he recovered an acidic substance which he called "nuclein". [1]