| quantitative hypertrophy | <pathology> The abnormal multiplication or increase in the number of normal cells in normal arrangement in a tissue. Compare: hypertrophy. Origin: Gr. Plasis = formation (18 Nov 1997) |
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| quantitative perimetry | A plotting of the visual field in isopters of equal retinal sensitivity. (05 Mar 2000) |
| quantitative trait | A characteristic showing quantitative inheritance such as skin pigmentation in man. (12 Dec 1998) |
| quantity | Origin: F. Quantite, L. Quantitas, fr. Quantus bow great, how much, akin to quam bow, E. How, who. See Who. 1. The attribute of being so much, and not more or less; the property of being measurable, or capable of increase and decrease, multiplication and division; greatness; and more concretely, that which answers the question "How much?"; measure in regard to bulk or amount; determinate or comparative dimensions; measure; amount; bulk; extent; size. Hence, in specific uses: The relative duration of a tone. 2. <mathematics> That which can be increased, diminished, or measured; especially, anything to which mathematical processes are applicable. Quantity is discrete when it is applied to separate objects, as in number; continuous, when the parts are connected, either in succession, as in time, motion, etc, or in extension, as by the dimensions of space, viz, length, breadth, and thickness. 3. A determinate or estimated amount; a sum or bulk; a certain portion or part; sometimes, a considerable amount; a large portion, bulk, or sum; as, a medicine taken in quantities, that is, in large quantities. "The quantity of extensive and curious information which he had picked up during many months of desultory, but not unprofitable, study." (Macaulay) Quantity of estate, quantities whose values are sought. Source: Websters Dictionary (01 Mar 1998) |
| quantivalence | <chemistry> Valence. Origin: L. Quantus how much + E. Valence. Source: Websters Dictionary (01 Mar 1998) |
| quantivalent | <chemistry> Of or pertaining to quantivalence. Source: Websters Dictionary (01 Mar 1998) |
| quantum | <unit> The fundamental unit of electromagnetic energy. (09 Oct 1997) |
| quantum efficiency | The number of photons required for the formation of one oxygen molecule in photosynthesis. Varies from 8-14 depending on the system used to measure it. (18 Nov 1997) |
| quantum evolution | An extremely rapid evolutionarychange in a single genetic lineage, thought to result from a sudden and radical change in the species'environment. (09 Oct 1997) |
| quantum limit | The shortest wavelength found in an X-ray spectrum. (05 Mar 2000) |
| quantum mottle | Mottle caused by the statistical fluctuation of the number of photons absorbed by the intensifying screens to form the light image on the film; faster screens produce more quantum mottle. (05 Mar 2000) |
| quantum rectum | See: Q.R. Origin: L. However much is correct (05 Mar 2000) |
| quantum requirement | The number of quanta of light absorbed required for the transformation of one molecule; the inverse of the quantum yield. (05 Mar 2000) |
| quantum satis | See: q.s. Origin: L. However much is enough Quantum sink, in radiological imaging, the stage at which statistical information reaches its lowest level because of a low photon flux. (05 Mar 2000) |
| quantum speciation | The rapid evolution of a newspecies from a small population that ispartially or totally isolated from the parent population, the rapidspeciation occurs due to geneticdrift and founder effect and usuallyinvolves a few mutations that have a big impact on the organisms' observable physical traits. (09 Oct 1997) |