Zoology Unit 5 Homework Questions

Terms in this set (65)

Oviparous: producing young by means of eggs that are hatched after they have been laid by the parent.
Ovoviviparous: producing young by means of eggs that are hatched within the body of the parent, as in some snakes
Viviparous: bringing forth live young that have developed inside the body of the parent.
Radial Cleavage:Embryonic development in which early cleavage planes are symmetrical to the polar axis, each blastomere of one tier lying directly above the corresponding blastomere of the next layer; typically occurs with regulative cleavage.
Regulative Cleavage: embryonic development in which the fertilized ovum undergoes indeterminate cleavage, producing blastomeres that have similar developmental potencies and are each capable of giving rise to a single embryo.
Mosaic Development: development characterized by independent differentiation of each part of the embryo; determinate cleavage.
Deuterostomes: a sub taxon of the Bilateria branch of the subkingdom Eumetazoa, within Animalia, and are distinguished from protostomes by their embryonic development.
Pharyngeal Slits: filter-feeding organs found in Invertebrate chordates (lancelets and tunicates) and hemichordates living in aquatic environments.
Spiral Cleavage: holoblastic cleavage that is typical of protostomes and that is characterized by arrangement of the blastomeres of each upper tier over the cell junctions of the next lower tier so that the blastomeres spiral around the pole to pole axis of the embryo
Blastopore: the opening of the central cavity of an embryo in the early stage of development.
Coelom: the body cavity in metazoans, located between the intestinal canal and the body wall.
Archenteron: the rudimentary alimentary cavity of embryo at the gastrula stage.