| Hardy-Weinberg law | <genetics> This genetics law states that the frequencyof a given genotype will reach equilibrium in a randomly mating population and will stay constant over many generations in the absence of selection pressures. (09 Oct 1997) |
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| Heidenhain's law | Glandular secretion is always accompanied by an alteration in the structure of the gland. (05 Mar 2000) |
| Hellin's law | Twins occur once in 89 births, triplets once in 892, and quadruplets once in 893. If the frequency of twins in a population is p, the frequency of triplets is p2, and the frequency of quadruplets is p3. (05 Mar 2000) |
| Profeta's law | The subject of congenital syphilis is immune against the acquired disease. (05 Mar 2000) |
| Henry's law | at equilibrium, at a given temperature, the amount of gas dissolved in a given volume of liquid is directly proportional to the partial pressure of that gas in the gas phase (this only holds for gases that do not react chemically with the solvent). (05 Mar 2000) |
| Hess' law | The amount of heat generated by a reaction is the same whether the reaction takes place in one step or several steps; i.e., dH values (and thus dG values) are additive. (05 Mar 2000) |
| hess's law | <chemistry> In going from a particular set of reactants to a particular set of products, the enthalpy change is the same whether the reaction takes place in one step or a series of steps, in other words, enthalpy is a state function. (09 Jan 1998) |
| Schutz' law | The rate of an enzyme reaction is proportional to the square root of the enzyme concentration; applied specifically to pepsin within a limited range. Synonym: Schutz' law. (05 Mar 2000) |
| Proust's law | The relative weights of the several elements forming a chemical compound are invariable. Synonym: Proust's law. (05 Mar 2000) |
| Hilton's law | The nerve supplying a joint supplies also the muscles which move the joint and the skin covering the articular insertion of those muscles. (05 Mar 2000) |
| second law of thermodynamics | <physics> All of the chemical and physical processes in a closed system tend to drive that system toward maximum entropy. Clausius statement: No device can operate in a cycle and allow heat to transfer from a colder body to a hotter body unless other compensating activities are taking place. Kelvin-Planck statement: no device can operate in a constant-temperature cycle and convert the heat it receives into work, unless other other compensating activities are taking place. (09 Oct 1997) |
| Hooke's law | The stress applied to stretch or compress a body is proportional to the strain, or change in length thus produced, so long as the limit of elasticity of the body is not exceeded. (05 Mar 2000) |
| Semon's law | An obsolete law stating that injury to the recurrent laryngeal nerve results in paralysis of the abductor muscle of the vocal cords before paralysis of the adductor muscles. (05 Mar 2000) |
| Sherrington's law | Every dorsal spinal nerve root supplies a particular area of the skin, the dermatome, which is, however, invaded above and below by fibres from the adjacent spinal segments. (05 Mar 2000) |
| Snell's law | For two given media, the sine of the angle of incidence bears a constant relation to the sine of the angle of refraction. Synonym: Descartes' law, Snell's law. (05 Mar 2000) |