Bio 1011 Chapter 32 Flashcards
Dorsal
Pertaining to the top of an animal with radial or bilateral symmetry
Determinate cleavage
future differentiation pathways are determined at an early developmental stage resulting in specialization.
Coelomate
the body cavity of higher metazoans, between the body wall and intestine, lined with a mesodermal epithelium.
Radial symmetry
When an object has many lines of symmetry that all go through a central point.
Bilateral Symmetry
When there is just one line that divides it into halves that are mirror images.
Indeterminate cleavage
A type of embryonic development in deuterostomes, in which each cell produced by early cleavage divisions retains the capacity to develop into a complete embryo.
deuterostome development
In animals, a developmental mode distinguished by the development of the anus from the blastopore; often also characterized by radial cleavage and by the body cavity forming as outpockets of mesodermal tissue.
bilateral symmetry
Characterizing a body form with a central longitudinal plane that divides the body into two equal but opposite halves.
triploblastic
Possessing three germ layers: the endoderm, mesoderm, and ectoderm. Most eumetazoa are triploblastic.
blastula
The hollow ball of cells marking the end stage of cleavage during early embryonic development.
body plan
A particular set of morphological and developmental traits, integrated into a functional whole- the living animal.
ventral
Pertaining to the underside, or bottom, of a bilaterally symmetrical animal.
ectoderm
The outermost of the three primary germ layers in animal embryos; gives rise to the outer covering and, in some phyla, the nervous system, inner ear, and lens of the eye.
coelom
A body cavity completely lined with mesoderm.
protostome development
In animals, a developmental mode distinguished by the development of the mouth from the blastopore; often also characterized by spiral cleavage and by the body cavity forming when solid masses of mesoderm split.
archenteron
The endoderm-lined cavity, formed during the gastrulation process, that develops into the digestive tract of an animal.
tissues
Groups of cells that have a common structure, function, or both.
gastrula
The two-layered, cup-shaped embryonic stage.
body cavity
A fluid-containing space between the digestive tract and the body wall.
spiral cleavage
A type of embryonic development in protostomes, in which the planes of cell division that transform the zygote into a ball of cells occur obliquely to the polar axis, resulting in cells of each tier sitting in the grooves between cells of adjacent tiers.
blastopore
The opening of the archenteron in the gastrula that develops into the mouth in protostomes and the anus in deuterostomes.
pseudocoelomates
An animal whose body cavity is lined by tissue derived from mesoderm and endoderm.
radial cleavage
A type of embryonic development in deuterostomes in that the planes of cell division that transform the zygote into a ball of cells are either parallel or perpendicular to the polar axis, thereby aligning tiers of cells one above the other.
anterior
Referring to the head end of a bilaterally symmetrical animal.
acoelomate
A solid-bodied animal lacking a cavity between the gut and outer body wall.
larva
A free-living, sexually immature form in some animal life cycles that may differ from the adult in morphology, nutrition, and habitat.
metamorphosis
The resurgence of development in an animal larva that transforms it into a sexually mature adult.
gastrulation
The formation of a gastrula from a blastula.
endoderm
The innermost of the three primary germ layers in animal embryos; lines the archenteron and gives rise to the liver, pancreas, lungs, and the lining of the digestive tract.
cleavage
The process of cytokinesis in animal cells, characterized by pinching of the plasma membrane; specifically, the succession of rapid cell divisions without growth during early embryonic development that converts the zygote into a ball of cells.
mesoderm
The middle primary germ layer of an early embryo that develops into the notochord, the lining of the coelom, muscles, skeleton, gonads, kidneys, and most of the circulatory system.
diploblastic
Having two germ layers.
