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 blastula 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. The blastula follows the morula and precedes the gastrula in the development sequence.
blastula (plural: blastulae) [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.
~ A ball of cells surrounding a fluid-filled cavity (the blastocoel) that is produced by the repeated cleavage of a zygote. PICTURE
blending Term applied to 19th century belief that parental traits "blended" in their offspring; disproven by Mendel's work.
(blas-tyoo-la) [Gk. blastos, sprout]
The hollow ball of cells marking the end stage of cleavage during early embryonic development.
~ - 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.
The ~ turns into gastrula in a process known as gastrulation.
Image Diversity: gastrula
9. What is gastrulation? How during gastrulation are the first two germ layers formed? What are these germ layers?
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 ~. A fluid-filled cavity, the blastocoel, forms within it.
During this entire process ...
Embryology: ~, ectoderm, endoderm, fertilization, gestation period. meiosis, mesoderm, mitosis, reproduction, gamete, zygote, differentiation, external fertilization, hermaphrodite, homologous structures, internal fertilization, ovum, placenta, reproductive system, sexual reproduction ...
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, ~, ~tion, chorion, chrysalis, cleavage, ectoderm, embryo, embryogenesis, embryogeny, embryology, endoderm, evocation, extra-embryonic membrane, fetus(or foetus), gastrula, gastrulation, germ layer, germ plasm, germ, germination, ...
The zygote undergoes a series of cell divisions, called cleavage, to form a hollow, multicellular ball known as a ~. The ~ then folds in on itself to form a gastrula, a double-walled structure with an opening to the outside called the blastopore.
Problem 9: Structure of the ~
The sheet of cells in the ~ 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). ~ derived from these cells were then used to generate totipotent embryonic stem cells.
It was the nuclei from these ES cells that were transplanted into enucleated eggs.
The process of movements and infoldings of embryonic cells destined to become endoderm in early animal embryos, immediately following ~ (or blastoderm) stage, generating the blastopore.
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.
Terms and Conditions ...
gastrula /GAST-trəl-lə/ 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 ~ to form a two- or ...
See also: What is the meaning of Embryo, Cells, Cell, Organ, Biology?