What's the difference between oviparous and viviparous?

Oviparous


Definition:

  • (a.) Producing young from rggs; as, an oviparous animal, in which the egg is generally separated from the animal, and hatched after exclusion; -- opposed to viviparous.

Example Sentences:

  • (1) These putative mutations, designated "total mutation," can be recognized only in embryos of oviparous animals.
  • (2) These results show that resorption of the yolk during follicular atresia in an oviparous vertebrate is correlated with the presence of egg yolk proteins combined with HDL in the plasma.
  • (3) The stationary and oviparous E. gallinacea and T. penetrans reveal an extensive and irreversible change of their midgut epithelium.
  • (4) The ligand specificity of the avian oocyte lipoprotein receptor supports the hypothesis that vitellogenin, which has evolved in oviparous species, represents a counterpart to mammalian apolipoprotein E.
  • (5) Progesterone (P), 17-OH-progesterone (17-OH-P), androstenedione (A), dehydroepiandrosterone (DHEA), testosterone (T), 5 alpha-dihydrotestosterone (5 alpha-DHT), and 17 beta-estradiol (E2) were measured by RIA in plasma and testes of 114 males of the oviparous lizard Podarcis s. sicula raf, a species that displays annual hibernating cycles.
  • (6) The structural and functional importance of eggshell magnesium--mainly in the cone layer--for embryonic viability and hatchability of oviparous species supports the hypothesis that magnesium deficit may have had a direct role in dinosaur extinction.
  • (7) We investigated the regulation of Re by progesterone in a mammalian model (proestrous hamster uterus) and an avian model (DES-primed chick oviduct), under the same assay conditions, in an effort to compare progesterone action in viviparous and oviparous species.
  • (8) These conditions may still exist in present-day oviparous amphibians.
  • (9) In this paper is also presented a discussion about the different modes of reproduction oviparity and viviparity (placental and non-placental) and their variations according to families, genus and species.
  • (10) Many dinosaurs were oviparous, producing hard-shelled eggs, yet the reproductive system of dinosaurs has proven difficult to investigate, due to poor preservation of soft anatomy.
  • (11) Vitellogenesis is the process of yolk formation in rapidly growing oocytes of oviparous species.
  • (12) No dichotomy exists among oviparous, amniotic vertebrates with respect to sources of calcium used by developing embryos, but one does exist with respect to patterns of mobilization of this element.
  • (13) In oviparous vertebrates estrogens induce hepatic synthesis of vitellogenin (VG), a blood protein sequestered in vitellogenic oocytes and from which lipovitellin (LV) and phosvitin are derived.
  • (14) This similarity of reproductive functional morphology between crocodilians and birds may implicate the evolution of an archosaurian mode of oviparity that may shed light on dinosaur reproduction.
  • (15) The old females are oviparous, but eggs contain a third stage infective larva.
  • (16) It is suggested that measurement of plasma zinc provides a simple and accurate technique for the estimation of vitellogenin production and reproductive status in the domestic fowl and that this may be applied to other oviparous vertebrates.
  • (17) This fish is oviparous and breeds once a year during the rainy season (July throught September).
  • (18) We suggest that in ancestral amphibians with oviparity and external fertilization, eggs moved rapidly through the oviduct after ovulation and that ovarian and oviducal PGF served as an endocrine hormone coordinating oviducal contractions and central nervous system-controlled oviposition behavior.
  • (19) We report a phenomenon previously unknown for oviparous animals; in Aedes aegypti mosquitoes a serine carboxypeptidase is synthesized extraovarially and then internalized by oocytes.
  • (20) Relaxin plays a critical role in viviparity and has recently been implicated as a hormone of oviparity as well.

Viviparous


Definition:

  • (a.) Producing young in a living state, as most mammals, or as those plants the offspring of which are produced alive, either by bulbs instead of seeds, or by the seeds themselves germinating on the plant, instead of falling, as they usually do; -- opposed to oviparous.

Example Sentences:

  • (1) This series of transitions at the embryonic age (up to the time of egg viviparity) is connected with ecological peculiarities of different species.
  • (2) The uterine epithelium of the viviparous Salamandra atra and the ovoviviparous Salamandra salamandra was studied in non pregnant and ovulating females and in females during different stages of pregnancy.
  • (3) Based on in vivo and in vitro modulation of immune responses by placental products, it is concluded that: 1) allograft enhancement and high production of IgG1 antibodies are not linked to the same glycoprotein, 2) the immunomodulators in relation to the protection of viviparity appear to be located at the exclusion limits of Sephacryl S-200 (i.e.
  • (4) Splenic cells from pregnant and non-pregnant viviparous lizards (Chalcides ocellatus) were stimulated in vitro with the mitogens, concanavalin A (Con A), phytohemagglutinin (PHA) and Escherichia coli lipopolysaccharide (LPS).
  • (5) It therefore appears that in the genus Wuchereria, as in the other viviparous filarioids, the phenomenon of speciation is evident first of all in the morphology of the microfilaria, the stage most susceptible to selection pressures.
  • (6) A plasma steroid binding protein (SHBP) with medium-high affinity and limited capacity was characterized in the viviparous water snake, Nerodia.
  • (7) We investigated the regulation of Re by progesterone in a mammalian model (proestrous hamster uterus) and an avian model (DES-primed chick oviduct), under the same assay conditions, in an effort to compare progesterone action in viviparous and oviparous species.
  • (8) This character opposes these species to the other viviparous Filariae and stresses the originality of the Oswaldofilariinar.
  • (9) The neurosecretory A cells of the pars intercerebralis of the viviparous fly Glossina fuscipes fuscipes present important changes during the genital cycle.
  • (10) Viviparity, on the other hand, allows the growth of a much larger fetus, offers great protection and is highly efficient.
  • (11) Steroid concentrations in plasma and follicular tissues (theca plus granulosa layers) were determined by radioimmunoassay in the aplacental viviparous ray, Torpedo marmorata, during various stages of the reproductive cycle.
  • (12) Etiology was determined to be a viviparous pinworm-like nematode of the genus Proatractis (Family Atractidae).
  • (13) In this paper is also presented a discussion about the different modes of reproduction oviparity and viviparity (placental and non-placental) and their variations according to families, genus and species.
  • (14) The ability of arachidonic acid (AA) and prostaglandins of the two series to induce parturition in vivo and oviducal contraction in vitro was studied in the viviparous lizard Sceloporus jarrovi.
  • (15) In the viviparous guppy, fertilization and gestation are intrafollicular.
  • (16) Here we described the emergence of T-cell immune capability in the viviparous lizard (Chalcides ocellatus) throughout embryonic development (stages 36-41 of Zada and El Deeb, 1984) and in newborns.
  • (17) Uterine contractility was investigated in the viviparous lizard Tiliqua rugosa.
  • (18) On the basis of these observations we speculate that viviparity might occur in vivo with consequent autoinfections; if so, this might explain some puzzling clinical and epidemiological features of haemonchosis, as well as the incomplete efficacy of current control measures.
  • (19) In a previous study we characterized an oviduct progesterone receptor in the viviparous snake, Nerodia, and in this study we describe changes in receptor during the reproductive cycle.
  • (20) The Viviparous-1 (Vp1) gene is required for expression of the C1 regulatory gene of the anthocyanin pathway in the developing maize seed.