An Intruduction to Animal Diversity
Terms : Hide Images
| 534198616 | animals | multicellular, heterotrophic eukaryotes with tissues developed from embryonic layers | |
| 534198617 | collagen | the most abundant structural protein that helds together the animal cells | |
| 534198618 | 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. | |
| 534198619 | blastula | The hollow ball of cells marking the end stage of cleavage during early embryonic development | |
| 534198620 | gastrulation | developmental process in which three distinct cell layers form in an embryo: the endoderm, mesoderm, and ectoderm | |
| 534198621 | gastrula | a stage of embryonic development characterized by the differentiation of the cells into the ectoderm and endoderm germ layers and by the formation of the archenteron | |
| 534198622 | larva | A free-living, sexually immature form in some animal life cycles that may differ from the adult in morphology, nutrition, and habitat. | |
| 534198623 | metamorphosis | the marked and rapid transformation of a larva into a juvenile, which resembles the adult but is not yet sexually mature. | |
| 534198624 | Hox genes | Series of genes that controls the differentiation of cells and tissues in an embryo | |
| 534198625 | choanoflagellets | closest living relatives to the animalia | |
| 534198626 | Ediacaran biota | An early group of soft-bodied, multicellular eukaryotes known from fossils that range in age from 565 million to 550 million years old. | |
| 534198627 | Cambrian explosion | A burst of evolutionary origins when most of the major body plans of animals appeared in a relatively brief time in geologic history; recorded in the fossil record about 535 to 525 million years ago. | |
| 534198628 | radial symmetry | body plan in which body parts repeat around the center of the body; characteristic of sea anemones and sea stars | |
| 534198629 | bilateral symmetry | body plan in which only a single, imaginary line can divide the body into two equal halves; characteristic of worms, arthropods, and chordates | |
| 534198630 | dorsal side | top side, back of an animal - the spine side, away from the abdomen | |
| 534403176 | ventral side | The underside, belly, or the lower body surface | |
| 534403177 | anterior end | the end of an animal that contains its head | |
| 534403178 | posterior end | the end of an animal that contains its tail | |
| 534403179 | cephalization | concentration of sense organs and nerve cells at the front of an animal's body (head and brain) | |
| 534403180 | sessile | describes an organism that remains attached to a surface for its entire life - radial animals | |
| 534403181 | planktonic | drifting passively with currents - radial animals | |
| 534403182 | Germ layers | ectoderm, endoderm, mesoderm | |
| 534403183 | 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 | |
| 534403184 | 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 | |
| 534403185 | archenteron | The endoderm-lined cavity, formed during gastrulation, that develops into the digestive tract of an animal. | |
| 534403186 | diploblastic | Term for animals with just two germ layers - the ectoderm and endoderm. Include Cnidarians and comb jellies. | |
| 534403187 | mesoderm | the middle germ layer that develops into muscle and bone and cartilage and blood and connective tissue | |
| 534403188 | triploblastic | Possessing three germ layers: the endoderm, mesoderm, and ectoderm. Most eumetazoans are triploblastic. | |
| 534403189 | body cavity | a fluid- or air-filled space between the digestive tract and the body wall | |
| 534403190 | coelom | body cavity | |
| 534403191 | coelomates | An animal that possesses a true coelom (a body cavity lined by tissue completely derived from mesoderm). - ex. earthworm | |
| 534403192 | pseudocoelomates | An animal whose body cavity is lined by tissue derived from mesoderm and endoderm. ex. round worm | |
| 534403193 | acoelomates | animals, such as flatworms, that do not have a body cavity | |
| 534403194 | Protostome development | Spiral and determinate cleavage, solid masses of mesoderm split and form coelom, mouth developes from blastopore. | |
| 534403195 | Deuterostome development | Radial and indeterminate cleavage, folds of archenteron form coelom, anus develops from blastopore. | |
| 534403196 | determinate cleavage | A type of embryonic development in protostomes that rigidly casts the developmental fate of each embryonic cell very early. | |
| 534403197 | 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. | |
| 534403198 | blastopore | in a gastrula, the opening of the archenteron that typically develops into the anus in deuterostomes and the mouth in protostomes. | |
| 534403199 | Points of Agreement | 1. All animals share a common ancestor 2. Sponges are basal animals 3. Eumetazoa is a clade of animals with true tissues 4. Most animal phyla belong to the clade Bilateria 5. Chordates and some other phyla belong to the clade Deuterostomia | |
| 534403200 | All animals share a common ancestor | both trees indicate that animals are monophyletic, forming a clade called Metazoa | |
| 534403201 | Sponges are basal animals | Among the extant taxa, sponges branch from the base of both animal trees. | |
| 534403202 | Eumetazoa is a clade of animals with true tissues | all animals except for sponges and a few other groups belong to a clade of eumetazoans(true animals). Basal eumetazoans are diploblastic and generally have radial symmetry | |
| 534403203 | Ecdysozoans | A major lineage of protostomes (Ecdysozoam) that grow by shedding their external skeletons (molting) and expanding their bodies. Includes arthropoda (insects) and nematoda (roundworms). | |
| 534403204 | Lophotrochozoans | One of the two groups of protostomes identified as a clade by molecular evidence. Lophotrochozoans include organisms that have lophophores or trochophore larvae. | |
| 534403205 | lophophore | In some lophotrochozoan animals, including brachiopods, a crown of ciliated tentacles that surround the mouth and function in feeding. | |
| 534403206 | trochophore larva | Distinctive larval stage observed in some lophotrochozoan animals, including some annelids and molluscs. |
