| frameshift mutation | <molecular biology> A type of mutation that results from insertion or deletion of a single nucleotide into, or from, an open reading frame in the normal DNA sequence. Normally, the genetic code is read in the wrong frame, three nucleotides at a time, and the entire sequence downstream of the mutation, is translated into a polypeptide with a garbled amino acid sequence from the mutated codon onwards. These mutations may be induced by certain types of mutagens or may occur spontaneously and usually result in the generation, downstream, of nonsense, chain termination codons. Synonym: addition mutation, addition-deletion mutation, deletion mutation, reading-frameshift mutation. (21 Jun 2000) |
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| lethal mutation | <genetics, molecular biology> Mutation that eventually results in the death of an organism carrying the mutation. (18 Nov 1997) |
| alveolar point | The most anterior point on the maxillary alveolar process in the midline. Synonym: alveolar point, prostheon. Origin: G. Ntr. Of prosthios, foremost (05 Mar 2000) |
| anterior focal point | The point where parallel rays from the retina are focused. (05 Mar 2000) |
| apophysial point | The centre of the root of the anterior nasal spine. Synonym: apophysary point, apophysial point, spinal point. (05 Mar 2000) |
| arrow point tracing | A tracing of mandibular movements made by means of a device attached to the opposing arches; its shape resembles that of an arrowhead or a Gothic arch, and when the instrument's marking point is at the apex of the arch, the jaws are considered to be in centric relation. Synonym: arrow point tracing, Gothic arch tracing, Gothic arch, stylus tracing. (05 Mar 2000) |
| auricular point | A craniometric point at the centre of the opening of the external acoustic meatus; or, in certain cases, the middle of the upper edge of this opening. Synonym: auricular point. Origin: L. Auricularis, pertaining to the ear (05 Mar 2000) |
| axial point | One of two point's in a compound optical system so related that a ray directed toward the first point will appear to have passed through the second point parallel to its original direction. Synonym: axial point. (05 Mar 2000) |
| boiling point | This is the temperature at which the vapor pressure of a given liquid reaches atmospheric pressure (and thus starts to boil). (09 Oct 1997) |
| boiling point elevation | This is the phenomenon of increasing the temperature at which a liquid boils by dissolving another substance in the liquid (for example: you can raise the temperature at which water boils by adding salt to it). (09 Oct 1997) |
| Cannon's point | The location in the mid-transverse colon at which innervation by superior and inferior mesenteric plexuses overlap at the junction of the primitive midgut and hindgut, frequently resulting in narrowing evident on barium enema. See: Cannon's ring. Synonym: Cannon's ring. (05 Mar 2000) |
| painful point | See: Valleix's points. (05 Mar 2000) |
| malar point | Apex of the tuberosity of the zygomatic (malar) bone. (05 Mar 2000) |
| maximum occipital point | The point on the squama of the occipital bone farthest from the glabella. (05 Mar 2000) |
| Mayo-Robson's point | A point just above and to the right of the umbilicus, where tenderness on pressure exists in disease of the pancreas. (05 Mar 2000) |