| sex chromosomes | The homologous chromosomes that are dissimilar in the heterogametic sex. There are the x chromosome, the y chromosome, and the w, z chromosomes (in animals in which the female is the heterogametic sex (the silkworm moth bombyx mori, for example). In such cases the w chromosome is the female-determining and the male is zz. (12 Dec 1998) |
|---|---|
| nonhomologous chromosomes | <genetics> Chromosome's that are not members of the same pair. (05 Mar 2000) |
| double minute chromosomes | <genetics, molecular biology> Paired, extrachromosomal elements lacking centromeres, often associated with a drug resistance gene. (05 Mar 2000) |
| duplication of chromosomes | A chromosome aberration resulting from unequal crossing over or exchange of segments between two homologous chromosomes; one chromosome of the pair loses a small segment, while the other gains this segment; the chromosome gaining the segment has undergone duplication while its homologue has undergone deletion. See: haemoglobin Lepore. (05 Mar 2000) |
| inversion of chromosomes | A chromosome aberration resulting from a double break in a segment of the chromosome, with end for end rotation of the fragment between the fracture lines, and refusion of the fragments; this results in reversal of the order of genes in that segment. (05 Mar 2000) |
| artificial | Made by art, not natural or pathological. Origin: L. Ars = art, facere = to make (18 Nov 1997) |
| artificial active immunity | See: acquired immunity. (05 Mar 2000) |
| artificial anatomy | The manufacture of models of anatomic structures, or the study of anatomy from such models. (05 Mar 2000) |
| artificial ankylosis | <orthopaedics> The surgical immobilisation of a joint (joint fusion). (27 Sep 1997) |
| artificial anus | An opening into the bowel, usually in the right or left flank, as a result of a colostomy. (05 Mar 2000) |
| artificial Carlsbad salt | A mixture of potassium sulfate, sodium chloride, sodium bicarbonate, and dried sodium sulfate; a laxative. (05 Mar 2000) |
| artificial classification | <zoology> Classification based on convenient or conspicuous diagnostic characters without attention to characters indicating relationship, often a classification based on a single arbitrarily chosen character, rather than an evaluation of the totality of characters. (09 Jan 1998) |
| artificial crown | A fixed restoration of the major part of the entire coronal part of a natural tooth; usually of gold, porcelain, or acrylic resin. (05 Mar 2000) |
| artificial dentition | <dentistry> A synthetic replacement for all of your teeth in either your upper or your lower jaw. (08 Jan 1998) |
| artificial eye | A curved disk of opaque glass or plastic, containing an imitation iris and pupil in the centre, inserted beneath the eyelids and supported by the orbital contents after evisceration or enucleation; it may be ready-made (stock) or custom-made. (05 Mar 2000) |