(n.) The production of two or more embryos in one seed, due either to the existence and fertilization of more than one embryonic sac or to the origination of embryos outside of the embryonic sac.
Example Sentences:
(1) However a somewhat later onset of first menstruations is characteristic of the women having a tendency to polyembryony-Hormonal changes taking place in the course of acceleration are apparently one of the causes of the decrease of the twin births frequency.
(2) The 0.6% concentration of acetone disturbed only the fertility of the eggs; lowest concentrations significantly increased the frequency of polyembryony.
(3) The authors made an investigation in detail on the pedigree history of polyembryony and systematic analysis of two sets of male triplets.
(4) The effect of this process on the women characterized by a tendency to polyembryony was more conspicuous, than in the average on the population as a whole.
(5) Ecological diversification, indicated by phylogenetic association of definitive hosts and parasites, and by changes in ecological components of life cycle patterns, is more conservative evolutionarily than diversification in developmental patterns, indicated by the appearance of unique larval stages, asexual proliferation of larvae, polyembryony, and heterochronic changes.
Sac
Definition:
(n.) See Sacs.
(n.) The privilege formerly enjoyed by the lord of a manor, of holding courts, trying causes, and imposing fines.
(n.) See 2d Sack.
(n.) A cavity, bag, or receptacle, usually containing fluid, and either closed, or opening into another cavity to the exterior; a sack.
Example Sentences:
(1) Both apertures were repaired with great caution using individual sutures without resection of the hernial sac.
(2) Tracheal mucus transport rate (TMTR) and quantitative clearance of aerosolized Escherichia coli from the trachea, lung, and air sac were measured in healthy unanesthetized turkeys and in turkeys exposed by aerosol to a La Sota vaccine strain of Newcastle disease virus (NDV).
(3) The wall of the yolk sac thickens as a result of this infolding and the densely packed capillaries.
(4) After intravenous or dorsal lymph sac injections of 3H-22:6, most of the retinal label was seen in rod photoreceptor cells.
(5) The buccal glands of adults of the Southern Hemisphere lamprey Geotria australis consist of a pair of small, bean-shaped, hollow sacs, embedded within the basilaris muscle in the region below the eyes and to either side of the piston cartilage.
(6) Ultrastructural examination of noncartilaginous regions of the tumor demonstrated mesenchymal cells with features suggestive of cartilaginous differentiation, viz, scalloped cell membranes, sac-like distension of abundant rough endoplasmic reticulum, and a matrix containing fibrillary and finely granular material.
(7) On the other hand, esophageal emptying of solid isotopic meals may show the persistence of food in the diverticular sac long time after the meal.
(8) Both genes are expressed in the fetal liver, gut, and visceral endoderm of the yolk sac and are repressed shortly after birth in the liver and gut.
(9) The in vitro absorption by rat jejunal and ileal gut sacs of soluble antigen-antibody complexes and of antigen alone was compared.
(10) In two almost identical experiments, all OTC treatment groups had significantly lower mean air sac lesion scores than the unmedicated challenged controls.
(11) After clusters of pigmented epithelial cells have rested immobile in the yolk sac of Blennius pholis for 2-4 days (Trinkaus, '88), their constituent cells transform into mesenchymal, dendritic melanocytes.
(12) The patient, a 28-year-old woman, in her ninth week of pregnancy, was operated on for stage Ia, mixed germ cell tumor (grade 3 immature teratoma + yolk sac tumor) of AFP decreased to the normal level.
(13) Using the experimental model of the everted sac prepared from rat jejuna, kinetic studies on [14C]oleic acid uptake from bile salt micelles were conducted in the presence and absence of phosphatidylcholine.
(14) Cadmium, anti-visceral yolk sac antibody (AVYS) and trypan blue all inhibited pinocytosis in a concentration-dependent fashion when added to the culture medium, although at low concentrations trypan blue was slightly stimulatory.
(15) In each rabbit, a single fetal sac was opened, the umbilical vessels were cannulated and the placenta was perfused in situ with buffered Krebs solution containing Dextran.
(16) Although small amounts of AFP are synthesized by sharks in the liver, the greatest site of synthesis is actually the stomach, with smaller amounts synthesized in the intestinal mucosa; no synthesis was observed in the shark yolk sac.
(17) A stem cell line has been obtained with cell culture, having a germ cell character and a yolk sac configuration.
(18) We postulate that the apposition of trophotaenial epithelium to the internal ovarian epithelium constitutes a placental association equivalent to a noninvasive, epithelioform of an inverted yolk sac placenta.
(19) In vivo recirculating perfusion (n = 5) and in vitro everted sac incubation (n = 8) were employed.
(20) In the second hypertrophied form [Type II], the endoplasmic reticulum is very prominent and occurs as a series of grossly dilated sacs of irregular shape.