| saemiconservative replication | Replication in which a double-stranded DNA (dsDNA) produces two daughter dsDNA, each of which contains one of the original chains and one newly synthesised strand. (05 Mar 2000) |
|---|---|
| saltatory replication | The sudden amplification of a DNA sequence to generate many copies in a tandem arrangement. Possible mechanism for the origin of satellite DNA. (18 Nov 1997) |
| semiconservative replication | <molecular biology> The system of replication of DNA found in all cells in which each daughter cell receives one old strand of DNA and one strand newly synthesised at the preceding S phase. The existence of semiconservative replication was demonstrated by the Meselson Stahl experiment and implies the two or multi strandedness of DNA. (18 Nov 1997) |
| DNA replication | <molecular biology> The process whereby a copy of a DNA molecule is made and thus the genetic information it contains is duplicated. The parental double stranded DNA molecule is replicated semi conservatively, i.e. Each copy contains one of the original strands paired with a newly synthesised strand that is complementary in terms of at and GC base pairing. Though in this sense conceptually simple, mechanistically a complex process involving a number of enzymes. (18 Nov 1997) |
| origin of replication | <molecular biology> Regions of DNA that are necessary for its replication to begin, such as pBR322 ori, required for plasmid replication. (18 Nov 1997) |
| unidirectional replication | Replication in which there is movement by a single replication fork. (05 Mar 2000) |
| arterial circle of cerebrum | An anastomotic "circle" of arteries (roughly pentagonal in outline) at the base of the brain, formed, sequentially and in anterior to posterior direction, by the anterior communicating artery, the two anterior cerebral, the two internal carotid, the two posterior communicating, and the two posterior cerebral arteries. Synonym: circulus arteriosus cerebri, circle of Willis. (05 Mar 2000) |
| articular vascular circle | An anastomosis of vessels encircling a joint. See: articular vascular network. Synonym: circulus articularis vasculosus. (05 Mar 2000) |
| Baudelocque's uterine circle | A constriction located at the junction of the thinned lower uterine segment with the thick retracted upper uterine segment, resulting from obstructed labour; this is one of the classic signs of threatened rupture of the uterus. Synonym: Bandl's ring, Baudelocque's uterine circle, Scanzoni's second os. (05 Mar 2000) |
| Pagenstecher's circle | In the case of a freely movable abdominal tumour, the mass is moved throughout its entire range, its position at intervals being marked on the abdominal wall; when these points are joined, a circle is formed, the centre of which marks the point of attachment of the tumour. (05 Mar 2000) |
| vascular circle | The circle around the mouth formed by the inferior and superior labial arteries. Synonym: areolar venous plexus. (05 Mar 2000) |
| vascular circle of optic nerve | <anatomy, nerve> A network of branches of the short ciliary arteries on the sclera around the point of entrance of the optic nerve. Synonym: circulus vasculosus nervi optici, circulus arteriosus halleri, circulus zinnii, Haller's circle, Zinn's corona, Zinn's vascular circle. (05 Mar 2000) |
| Ramsden circle | <microscopy> The circular spot of light formed at that distance above the eyepiece where the chief image forming rays cross, the back focal plane of the eyepiece. The objective back focal plane is in conjugate focus in this same plane. In visual microscopy, the point where the pupil of the eye is placed. (05 Aug 1998) |
| venous circle of mammary gland | areolar venous plexus |
| Carus' circle | An imaginary curved line obtained from a mathematical formula, supposed to indicate the outlet of the pelvic canal. Synonym: Carus' circle. (05 Mar 2000) |