| mobile genetic element | <molecular biology> Small, mobile DNA sequences that can replicate and insert copies at random sites within chromosomes. They have nearly identical sequences at each end, oppositely oriented (inverted) repeats and code for the enzyme, transposase, that catalyses their insertion. Bacteria have two types of transposon, simple transposons that have only the genes needed for insertion and complex transposons that contain genes in addition to those needed for insertion. Eukaryotes contain two classes of mobile genetic elements, the first are like bacterial transposons in that DNA sequences move directly. The second class (retrotransposons) move by producing RNA that is transcribed, by reverse transcriptase, into DNA which is then inserted at a new site. (13 Nov 1997) |
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| mobile | 1. Capable of being moved; not fixed in place or condition; movable. "Fixed or else mobile." 2. Characterised by an extreme degree of fluidity; moving or flowing with great freedom; as, benzine and mercury are mobile liquids; opposed to viscous, viscoidal, or oily. 3. Easily moved in feeling, purpose, or direction; excitable; changeable; fickle. "The quick and mobile curiosity of her disposition." (Hawthorne) 4. Changing in appearance and expression under the influence of the mind; as, mobile features. 5. <physiology> Capable of being moved, aroused, or excited; capable of spontaneous movement. Origin: L. Mobilis, for movibilis, fr. Movere to move: cf. F. Mobile. See Move. Source: Websters Dictionary (01 Mar 1998) |
| mobile health units | Movable facilities in which diagnostic and therapeutic services are provided to the community. (12 Dec 1998) |
| mobile ion carrier | <chemistry> A molecule that allows ions to cross lipid bilayers. There are two classes: carriers and channels. Carriers, like valinomycin, form cage like structures around specific ions, diffusing freely through the hydrophobic regions of the bilayer. Channels, like gramicidin, form continuous aqueous pores through the bilayer, allowing ions to diffuse through. See: ion channels. (18 Nov 1997) |
| mobile part of nasal septum | The anterior movable part of the nasal septum formed by the medial crus of the greater alar cartilage on each side. Synonym: pars mobilis septi nasi, septum mobile nasi. (05 Mar 2000) |
| mobile spasm | A tonic spasm occurring in spastic infantile hemiplegia on attempted movement. (05 Mar 2000) |
| cor mobile | A heart that moves unduly on change of bodily position. Synonym: movable heart. (05 Mar 2000) |
| primum mobile | <astronomy> In the Ptolemaic system, the outermost of the revolving concentric spheres constituting the universe, the motion of which was supposed to carry with it all the inclosed spheres with their planets in a daily revolution from east to west. See Crystalline heavens, under Crystalline. "The motions of the greatest persons in a government ought to be, as the motions of the planets, under primum mobile." (Bacon) Origin: L, first cause of motion. Source: Websters Dictionary (01 Mar 1998) |
| septum mobile nasi | The anterior movable part of the nasal septum formed by the medial crus of the greater alar cartilage on each side. Synonym: pars mobilis septi nasi, septum mobile nasi. (05 Mar 2000) |
| actinide elements | Those elements with atomic numbers 89 to 103, corresponding to the lanthanides in the Periodic Table. Synonym: actinide elements. Origin: actinium, first element of the series (05 Mar 2000) |
| alkaline earth elements | Those element's in the family Be, Mg, Ca, Sr, Ba, and Ra, the hydroxides of which are highly ionised and hence alkaline in water solution. (05 Mar 2000) |
| alu elements | <molecular biology> A set of closely related genetic sequences, each about 300 base pairs long, in the human genome. There are 500,000 to 600,000 copies widely dispersed among all 46 chromosomes: They act as markers for human DNA sequences, although their function in the genome is unknown. The DNA fragments containing the Alu elements are formed by digesting genomic DNA with the restriction endonuclease Alu I. (14 Nov 1997) |
| rare earth elements | Those elements with atomic numbers 57-71 which closely resemble one another chemically and were once difficult to separate from one another. Synonym: rare earth elements. Origin: Lanthanum, first element of the series (05 Mar 2000) |
| P elements | A class of transposable elements in Drosophila responsible for hybrid dysgenesis; utilised as tools for introducing genes into new locations in the genome. (05 Mar 2000) |
| copia elements | A mobile genetic element with retrovirus-like sequence organization. (05 Mar 2000) |