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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 ...
The cell was first discovered by Robert Hooke in 1665 using a microscope. The first cell theory is credited to the work of Theodor Schwann and Matthias Jakob Schleiden in the 1830s. In this theory the internal contents of cells were called protoplasm and described as a jelly-like substance, sometimes called living jelly.
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.
Light micrograph of a moss's leaf cells at 400X magnification. The following outline is provided as an overview of and topical guide to cell biology: . Cell biology – A branch of biology that includes study of cells regarding their physiological properties, structure, and function; the organelles they contain; interactions with their environment; and their life cycle, division, and death.
A diagram of the mitotic phases. Mitosis is the process by which a eukaryotic cell separates the chromosomes in its cell nucleus into two identical sets in two nuclei. [8] During the process of mitosis the pairs of chromosomes condense and attach to microtubules that pull the sister chromatids to opposite sides of the cell. [9]
1672: Sir Isaac Newton: discovers that white light is a mixture of distinct coloured rays (the spectrum). 1673: Christiaan Huygens: first study of oscillating system and design of pendulum clocks; 1675: Leibniz, Newton: infinitesimal calculus. 1675: Anton van Leeuwenhoek: observes microorganisms using a refined simple microscope.
Detailed diagram of lipid bilayer of cell membrane The cell membrane , or plasma membrane, is a selectively permeable [ citation needed ] biological membrane that surrounds the cytoplasm of a cell. In animals, the plasma membrane is the outer boundary of the cell, while in plants and prokaryotes it is usually covered by a cell wall .
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 ...