What's the difference between meroblast and ovum?

Meroblast


Definition:

  • (n.) An ovum, as that of a mammal, only partially composed of germinal matter, that is, consisting of both a germinal portion and an albuminous or nutritive one; -- opposed to holoblast.

Example Sentences:

  • (1) A hypothesis is put forward on pathways of changes of prospective importance of blastocoele in the vertebrate phylogenesis, in connection with their transition to meroblastic development.
  • (2) During meroblastic cleavage, and continuing in the early blastula, zebrafish blastomeres divide rapidly and synchronously.
  • (3) Cleavage (stages 1-10) is meroblastic and produces a typical teleost blastoderm.
  • (4) The problem on changes in assimilation of yolk by the vertebrate embryo at transition from holoblastic to meroblastic development is discussed from comparative point of view, as well as on nature of yolk entoderm in Amniota and Anamnia.
  • (5) The meroblastic egg of the teleost, Fundulus heteroclitus, was studied electrophysiologically from cleavage to mid-gastrula stages.
  • (6) Meroblast formation was effected by clefts originating from the parasite plasmalemma and by fusion of vacuoles with each other.

Ovum


Definition:

  • (n.) A more or less spherical and transparent mass of granular protoplasm, which by a process of multiplication and growth develops into a mass of cells, constituting a new individual like the parent; an egg, spore, germ, or germ cell. See Illust. of Mycropyle.
  • (n.) One of the series of egg-shaped ornaments into which the ovolo is often carved.

Example Sentences:

  • (1) A specimen of a very early ovum, 4 to 6 days old, shown in the luminal form of imbedding before any hemorrhage has taken place, confirms that the luminal form of imbedding does occur.
  • (2) The results indicate that the sperm swelling test and the zona-free hamster ovum penetration assay are evaluating different functional qualities of sperm that are apparently not associated with each other.
  • (3) This study documents a molecular change in the murine ovum related to its exposure to oviductal fluid.
  • (4) The OCI-related membrane appeared a cause of OCI interference with fimbrial ovum capture by preventing the contact between the fimbrial cilia and the cumulus oophorus.
  • (5) Also, for determination of the fertilizing capacity of the semen, a zona-free hamster ovum penetration test was done in 49 men, while 14 men were studied by determination of the fertilization of human oocytes in vitro.
  • (6) The antiprogesterone RU 486 was utilized to evaluate the possible role of progesterone in ovum maturation, ovulation, fertilization, and embryo cleavage.
  • (7) It is suggested that the beta inhibitory activity of the uterus and the alpha excitatory activity of the rest of the oviduct are involved in the regulation of ovum transport.
  • (8) Among antigens possible unique to the reproductive process, sperm antigens, antigens of seminal plasma and of the ovum, antigens of placental hormones and of placenta specific proteins appear suitable targets of the production of fertility regulating vaccines.
  • (9) The preovulatory surge of gonadotropins activates a cascade of proteolytic enzymes resulting in the rupture of the follicular wall and the release of a fertilizable ovum during ovulation.
  • (10) The development of vaginal ultrasound transducers has facilitated ovum pick-up (OPU) by providing higher precision and less trauma than are found with laparoscopy and other ultrasound-assisted techniques.
  • (11) In Johnson v. Calvert, a surrogate mother in California failed to gain custody of the child she bore after gestating an embryo from the ovum and sperm of the couple who hired her.
  • (12) Risk factors that may theoretically alter ovum quality or the hormonal environment include ovulation induction, fertilization in vitro, delayed ovulation, and transperitoneal ovum migration.
  • (13) Thus, spermatozoa deposited in the vicinity of the USHG immediately following oviposition (to simulate a release of spermatozoa from this region) can be transported to the infundibulum and effectively fertilize the next ovum ovulated.
  • (14) However, they do not as yet permit a judgment as to the degree that ovum pickup through a fistula was impaired.
  • (15) We evaluated the differences between this group and those patients presenting either with a blighted ovum or beyond the first trimester, as well as the outcome of those patients with spotting early in gestation.
  • (16) It is too soon to learn whether this method will be reversible, but use of silastic should prevent adhesions while providing another mechanical barrier between ovum and sperm.
  • (17) Indomethacin was effective in preventing follicular rupture and ovum extrusion when administered simultaneously with gonadotropin.
  • (18) A 33% clinical pregnancy rate per ovum pick-up was achieved with the Buserelin-hMG treatment.
  • (19) The pregnancy rates were higher than a matched IVF series in the male factor and female ASAB groups and reached statistical significance for the ovum donation group.
  • (20) Lamellar structures, therefore, are considered to be storage material chiefly used in the second half of the cleavage for developmental processes in the rat ovum.

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