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This is an accepted version of this page This is the latest accepted revision, reviewed on 19 December 2024. Process in which chromosomes are replicated and separated into two new identical nuclei For the type of cell division in sexually reproducing organisms used to produce gametes, see Meiosis. For excessive constriction of the pupils, see Miosis. For the parasitic infestation, see Myiasis ...
Cell division in prokaryotes (binary fission) and eukaryotes (mitosis and meiosis). The thick lines are chromosomes, and the thin blue lines are fibers pulling on the chromosomes and pushing the ends of the cell apart. The cell cycle in eukaryotes: I = Interphase, M = Mitosis, G 0 = Gap 0, G 1 = Gap 1, G 2 = Gap 2, S = Synthesis, G 3 = Gap 3.
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 cell was first discovered by Robert Hooke in 1665, which can be found to be described in his book Micrographia. In this book, he gave 60 observations in detail of various objects under a coarse, compound microscope. One observation was from very thin slices of bottle cork. Hooke discovered a multitude of tiny pores that he named "cells".
This early, simple form of genetic recovery is similar to that occurring in extant segmented single-stranded RNA viruses (see influenza A virus). As duplex DNA became the predominant form of the genetic material, the mechanism of genetic recovery evolved into the more complex process of meiotic recombination , found today in most species.
These theories did not gain traction until more detailed electron-microscopic comparisons between cyanobacteria and chloroplasts were made, such as by Hans Ris in 1961 and 1962. [ 16 ] [ 17 ] These, combined with the discovery that plastids and mitochondria contain their own DNA, [ 18 ] led to a resurrection of the idea of symbiogenesis in the ...
While detection of biophotons has been reported by several groups, [3] [4] [5] hypotheses that such biophotons indicate the state of biological tissues and facilitate a form of cellular communication are still under investigation, [6] [7] Alexander Gurwitsch, who discovered the existence of biophotons, was awarded the Stalin Prize in 1941 for ...
During mitosis, which is also known as the M-phase, the segregation of the chromosomes occur. [36] DNA, like every other molecule, is capable of undergoing a wide range of chemical reactions. Modifications in DNA's sequence, on the other hand, have a considerably bigger impact than modifications in other cellular constituents like RNAs or ...