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  2. Cell theory - Wikipedia

    en.wikipedia.org/wiki/Cell_theory

    Since the membrane theory requires an impermanent solute to sustain cell shrinkage, these experiments cast doubt on the theory. Others questioned whether the cell has enough energy to sustain the sodium/potassium pump. Such questions became even more urgent as dozens of new metabolic pumps were added as new chemical gradients were discovered.

  3. Osmoregulation - Wikipedia

    en.wikipedia.org/wiki/Osmoregulation

    Osmoregulation is the active regulation of the osmotic pressure of an organism's body fluids, detected by osmoreceptors, to maintain the homeostasis of the organism's water content; that is, it maintains the fluid balance and the concentration of electrolytes (salts in solution which in this case is represented by body fluid) to keep the body fluids from becoming too diluted or concentrated.

  4. Homeostasis - Wikipedia

    en.wikipedia.org/wiki/Homeostasis

    Process control systems in a chemical plant or oil refinery maintain fluid levels, pressures, temperature, chemical composition, etc. by controlling heaters, pumps and valves. [ 90 ] The centrifugal governor of a steam engine , as designed by James Watt in 1788, reduces the throttle valve in response to increases in the engine speed, or opens ...

  5. Risk assessment - Wikipedia

    en.wikipedia.org/wiki/Risk_assessment

    Risk assessment can also be made on a much larger systems theory scale, for example assessing the risks of an ecosystem or an interactively complex mechanical, electronic, nuclear, and biological system or a hurricane (a complex meteorological and geographical system).

  6. Density - Wikipedia

    en.wikipedia.org/wiki/Density

    Density (volumetric mass density or specific mass) is a substance's mass per unit of volume.The symbol most often used for density is ρ (the lower case Greek letter rho), although the Latin letter D can also be used.

  7. Electroencephalography - Wikipedia

    en.wikipedia.org/wiki/Electroencephalography

    Electroencephalography (EEG) [1] is a method to record an electrogram of the spontaneous electrical activity of the brain.The biosignals detected by EEG have been shown to represent the postsynaptic potentials of pyramidal neurons in the neocortex and allocortex. [2]

  8. Stellar evolution - Wikipedia

    en.wikipedia.org/wiki/Stellar_evolution

    Representative lifetimes of stars as a function of their masses The change in size with time of a Sun-like star Artist's depiction of the life cycle of a Sun-like star, starting as a main-sequence star at lower left then expanding through the subgiant and giant phases, until its outer envelope is expelled to form a planetary nebula at upper right Chart of stellar evolution

  9. Wikipedia:Language learning centre/Word list - Wikipedia

    en.wikipedia.org/wiki/Wikipedia:Language...

    Eventually these words will all be translated into big lists in many different languages and using the words in phrase contexts as a resource. You can use the list to generate your own lists in whatever language you're learning and to test yourself. ==A==Isixhosa