| 释义 |
homologous, a.|həʊˈmɒləgəs|
[f. med.L. homo-log-us or Gr. ὁµόλογ-ος agreeing (see prec.) + -ous.]
Having the same relation, proportion, relative position, etc.; corresponding. Specifically:
1. a. Math. Having the same ratio or relative value as the two antecedents or the two consequents in a proportion, or the corresponding sides in similar figures.
1660Barrow Euclid v. def. 11, B and D are homologous or magnitudes of a like ratio. 1750Phil. Trans. XLVII. iv. 23 Comparing the homologous terms. 1855H. Spencer Princ. Psychol. (1872) II. vi. ix. 118 The quantitative relation between any two sides of the one, is equal to that between the homologous sides of the other.
b. Mod. Geom. Having a relation of homology, as two plane figures; homological; homographic and in the same plane. (See homology 4.)
1879Salmon Conics 59 Two triangles are said to be homologous, when the intersections of the corresponding sides lie on the same right line called the axis of homology; prove that the lines joining corresponding vertices meet in a point.
2. a. Biol. Having the same relation to an original or fundamental type; corresponding in type of structure (but not necessarily in function); said of parts or organs in different animals or plants, or of different parts or organs in the same animal or plant. (Distinguished from analogous: see quot. 1854 s.v. analogous 1 b.)
1846Owen in Rep. Brit. Assoc. 174 There exists doubtless a close general resemblance in the mode of development of homologous parts. 1868Darwin Anim. & Pl. II. 322 In the vertebrata the front and hind limbs are homologous. 1880Gray Struct. Bot. i. 6 The name of leaves has been..extended..from the green expansions which constitute foliage to other forms under which such appendages occur..The latter are homologous with leaves or the homologues of leaves.
b. Path. Of the same formation as the normal tissue of the part: said of morbid growths. (Opp. to heterologous.)
1871T. H. Green Introd. Pathol. (1873) 106 A growth primarily homologous may subsequently become heterologous. 1878T. Bryant Pract. Surg. I. 97 The cartilaginous tumour is homologous..if it springs from cartilage.
3. Chem. Applied to series of compounds differing in composition successively by a constant amount of certain constituents, and showing a gradation of chemical and physical properties; esp. to series of organic compounds differing by multiples of CH2, as the alcohols, aldehydes, ethers, etc.
1850Daubeny Atom. The. viii. (ed. 2) 252 Four classes of homologous bodies, to adopt the term which Gerhardt has proposed, namely, alcohols, ethers, aldehydes, and acids. 1869Roscoe Elem. Chem. 292 These homologous series of mono-, di-, tri-, and higher carbon groups. 1876Foster Phys. (1879) App. 677 The Acetic Acid Series..one of the most complete homologous series of organic chemistry.
4. a. In other applications: = Corresponding.
1837Brewster Magnet. 22 Making the homologous poles of two magnetized wires repel each other. 1855H. Spencer Princ. Psychol. (1872) II. vi. xiii. 173 A symmetrical figure is one in which the homologous parts on opposite sides are equal in magnitude. 1895Story-Maskelyne Crystallogr. §82 Two poles or planes thus symmetrically disposed in regard to an origin-plane will be termed homologous to each other in respect to that plane of symmetry.
b. Cytol. Of chromosomes: pairing at meiosis, and normally (except in the case of the sex chromosomes of some species) identical in morphology and in arrangement of genetic loci.
1903W. S. Sutton in Biol. Bull. IV. 238 The double basis of hybrid characters is to be found in the pairs of homologous chromosomes of the presynaptic germ-cells. 1920W. E. Agar Cytol. v. 125 It was found that there were in each diploid nucleus two chromosomes of each size... In the meiotic prophase the two chromosomes of each type, usually called homologous chromosomes, pair together to form the bivalents. 1970Ambrose & Easty Cell Biol. x. 327 The nature of the forces responsible for the pairing of homologous chromosomes in the early stages of prophase I, and for their separation at the diplotene stage, is not yet understood.
c. Med. Derived from or involving an organism or organisms of the same species; also, involving or containing antibodies or antigens that react specifically with one another, as when an antibody has been produced by injection of an antigen.
1915Jrnl. Path. & Bacteriol. XX. 76 Heterologous immunity, in which cancer cells from one species are used as antigens to immunise animals of strange species, is..different in many ways from homologous immunity. 1928Buchanan & Fulmer Physiol. & Biochem. Bacteria I. iii. 361 By the use of ox serum and complement he could secure marked agglutination of bacteria in a dilution of the homologous antiserum by itself too weak to produce any trace of agglutination. 1933W. W. C. Topley Outl. Immunity vi. 91 The antiserum that is produced by the inoculation into a suitable animal of a particular bacterium is frequently referred to as a homologous serum. 1946K. Landsteiner Specificity Serol. Reactions (rev. ed.) i. 8 Reactions of an antibody with the corresponding antigen are said to be homologous, while heterologous reactions..are those taking place with substances other than the inciting antigen. 1958Immunology I. 111 Morgan (1947) injected rhesus monkeys with homologous brain and cord in water-in-oil emulsion containing killed Mycobacterium tuberculosis. 1961Lancet 29 July 245/1 Serum-autoantibodies against, for example, thyroid or brain can be readily elicited in rabbits or guineapigs by immunisation with the relevant homologous or, indeed autologous, tissue. 1968J. C. Norman et al. Organ Perfusion & Preservation xxvii. 375 The feasibility of heterologous or homologous intermediate hosts for human resuscitative storage is untried. |