blastopore A mouth-like opening of the archenteron on the surface of an embryo in the gastrula stage. In many animals the blastopore becomes the anus, although in some it closes up at the end of gastrulation and may appear again at or near the same site. The blastopore is formed by an inward movement of the endoderm and mesoderm cells of the archenteron during gastrulation. Sometimes this movement is incomplete, so that an open pore does not develop; this explains the primitive streak of a bird or mammal embryo during gastrulation. In that case it is referred to as a ‘virtual’ blastopore. See also DEUTEROSTOMY PROTOSTOMY.
blastopore See archenteron.
More From encyclopedia.com
Gastrulation , gastrulation In the embryogenesis of a vertebrate, the next stage after the blastula, in which the three germ layers differentiate to form the triplo… Blastula , blastula The stage of development of an animal embryo that results from cleavage of a fertilized egg. This stage generally resembles a hollow ball wi… Amoeboid Movement , Skip to main content amoeboid movement amoeboid movement The mechanism of movement demonstrated by Amoeba and other cells that are capable of changin… Endoderm , Skip to main content endoderm endoderm (ĕn´dədûrm´), in biology, inner layer of tissue formed in the gastrula stage of the developing embryo. At the… Germ Layers , germ layers (primary germ layers) The layers of cells in an animal embryo at the gastrula stage, from which are derived the various organs of the ani… Companion Cell , Skip to main content companion cell
About this article
All Sources -
Updated Aug 08 2016 About encyclopedia.com content Print Topic
You Might Also Like