| law of biogenesis | The theory formulated by E.H. Haeckel that individuals in their embryonic development pass through stages similar in general structural plan to the stages their species passed through in its evolution; more technically phrased, the theory that ontogeny is an abbreviated recapitulation of phylogeny. Synonym: biogenetic law, law of biogenesis, Haeckel's law, law of recapitulation. (05 Mar 2000) |
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| law of constant numbers in ovulation | The number of ova discharged at each ovulation is nearly constant for any given species. (05 Mar 2000) |
| law of contiguity | When two ideas or psychologically perceived events have once occurred in close association they are likely to so occur again, the subsequent occurrence of one tending to elicit the other; this law figures prominently in modern theories of conditioning and learning. (05 Mar 2000) |
| law of contrary innervation | "all living functions are continually controlled by two opposite forces: augmentation or action on the one hand, and inhibition on the other." Synonym: law of contrary innervation. (05 Mar 2000) |
| law of definite proportions | The relative weights of the several elements forming a chemical compound are invariable. Synonym: Proust's law. (05 Mar 2000) |
| law of denervation | When a structure is denervated, its irritability to certain chemical agents is increased; e.g., the greater sensitivity of the pupil to acetylcholine after section and degeneration of the third nerve, and of the nictitating membrane to adrenaline after excision of the superior cervical ganglion. (05 Mar 2000) |
| law of excitation | A motor nerve responds, not to the absolute value, but to the alteration of value from moment to moment, of the electric current; i.e., rate of change of intensity of the current is a factor in determining its effectiveness. Synonym: Du Bois-Reymond's law. (05 Mar 2000) |
| law of gravitation | The attractive force between any two bodies is proportional to the product of their masses, and inversely proportional to the square of the distance between their centres. Synonym: law of gravitation. (05 Mar 2000) |
| law of independent assortment | Different hereditary factors assort independently when the gametes are formed; traits at linked loci are an exception. Synonym: Mendel's second law. (05 Mar 2000) |
| law of initial value | The direction of response of a body function to any agent depends to a large degree on the initial level of that function. Synonym: law of initial value. (05 Mar 2000) |
| law of intestine | Contraction above and relaxation below a stimulated point in the intestine. Synonym: law of intestine. (05 Mar 2000) |
| law of isochronism | A nerve and the muscle which it innervates have the same chronaxie values. (05 Mar 2000) |
| law of mass action | <chemistry> This law states that the rate of a given chemical reaction is proportional to concentration of the reactants. (09 Oct 1997) |
| law of multiple proportions | The relative weights in which two substances form a chemical union singly with a third are the same as, or simple multiples of, those in which they unite with each other; a corollary of the law of definite proportions. Synonym: law of multiple proportions. (05 Mar 2000) |
| law of partial pressures | Each gas in a mixture of gases exerts a pressure proportionate to the percentage of the gas and independent of the presence of the other gases present. Synonym: law of partial pressures. (05 Mar 2000) |