An early embryonic form produced by cleavage of a fertilized ovum and usually consisting of a single layer of cells surrounding a fluid-filled spherical cavity.
spherical, hollow mass of cells resulting from the division of the egg.
Source: Noland, George B. 1983. General Biology, 11th Edition. St. Louis, MO. C. V. Mosby ...
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The is an early stage of embryonic development in animals. It is produced by cleavage of a fertilized ovum and consisting of a spherical layer of cells surrounding a fluid-filled cavity.
permanent "blastula" of ciliated epidermal cells formed by experimental isolation of animal pole cells of the sea urchin embryo.
(plural: e) [Gr. blastos - germ, bud, shoot]. The multicellular embryo formed as a result of cleavage. In higher animals it contains a fluid-filled cavity called the blastocoele.
blastula A ball of cells surrounding a fluid-filled cavity (the blastocoel) that is produced by the repeated cleavage of a zygote. PICTURE ...
(blas-tyoo-la) [Gk. blastos, sprout]
The hollow ball of cells marking the end stage of cleavage during early embryonic development.
blastula - a cleavage stage embryo, typically a hollow ball of cells surrounding a cavity called the blastocoel; this term is used for (among others) echinoderm and amphibian embryos.
An early stage in the development of an embryo; it consists of a sphere of cells enclosing a fluid-filled cavity (blastocoel).
bleaching The expulsion of zooxanthellae by reef corals in response to stress.
blending See polygenic inheritance.
Blastulation and gastrulation establish the main body axis. Organ formation occurs in the next stage of the development of the embryo. During organ formation, cell division is accomplished by migration and aggregation.
What Sulston and his colleagues did with tracing the entire cell lineage would be exceedingly difficult for the vast majority of organisms. Most multicellular organisms have far more cells than C. elegans.
By the next day, continued cleavage has produced a hollow ball of thousands of cells called the blastula. A fluid-filled cavity, the blastocoel, forms within it.
During this entire process ...
Embryology: , ectoderm, endoderm, fertilization, gestation period.
Below: Whitefish blastula X 400
Mitosis in Plants
Plants form a spindle apparatus as animals do but plants lack centrioles.
After fertilization, when the egg is still in the oviduct, it begins to divide by mitosis to form a hollow fluid filled ball of cells called the . This process is called cleavage.
See also allantois, amnion, blastocyst, blastomere, blastula, blastulation, chorion, chrysalis, cleavage, ectoderm, embryo, embryogenesis, embryogeny, embryology, endoderm, evocation, extra-embryonic membrane, fetus(or foetus), gastrula, gastrulation, ...
The zygote undergoes a series of cell divisions, called cleavage, to form a hollow, multicellular ball known as a .
Problem 9: Structure of the blastula
The sheet of cells in the blastula of a developing animal embryo is called the:
Continued cleavage produces a morula and then a .
Because of unequal cell division, the blastocoel is located in the animal hemisphere.
Animals with less yolk (such as the sea urchin) also have an animal-vegetal axis.
Neuronal nuclei were transplanted into an oocyte from which the original nucleus had been removed (an enucleated oocyte). Blastula derived from these cells were then used to generate totipotent embryonic stem cells.
Lemaire P, Garrett N, Gurdon JB: Expression cloning of Siamois, a Xenopus homeobox gene expressed in dorsal-vegetal cells of e and able to induce a complete secondary axis.
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An early stage in the development of an animal embryo during which its shape is restructured by cell migration. The exact process differs in different animals, but in the more complex organisms it typically involves an infolding of the blastula to ...
See also: Cells, Embryo, Cell, Organ, Biology