An Overview of Animal Diversity
32.1 Animals are multicellular, heterotrophic eukaryotes with tissues that develop from embryonic layers
32.2 The history of animals spans more than half a billion years
32.3 Animals can be characterized by body plans
32.4 New views of animal phylogeny are emerging from molecular data
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| 2255036304 | tissues | groups of similar cells that perform a specific function in an organism | 0 | |
| 2255041406 | structure of animals | - multicellular eukaryotes - lack cell walls - body held together by proteins called collagen - sexual reproduction - diploid stage | 1 | |
| 2255047415 | Four defining features of animals body plan | 1) type of body symmetry 2) presence/absence of a fluid-filled body cavity 3) embryo development 4) number of tissue types in embryos | 2 | |
| 2255036305 | cleavage | a succession of mitotic cell divisions without cell growth between the divisions | 3 | |
| 2255036306 | blastula | The hollow ball of cells marking the end stage of cleavage during early embryonic development | 4 | |
| 2255062447 | blastocoel | the hollow cavity formed during the blastula stage | 5 | |
| 2255036307 | gastrulation | the process in which a gastrula develops from a blastula by the inward migration of cells - are the embryonic tissues that will develop into the adult body | 6 | |
| 2255036308 | gastrula | double-walled stage of the embryo resulting from invagination of the blastula | 7 | |
| 2255036309 | larva | the immature free-living form of most invertebrates and amphibians and fish which at hatching from the egg is fundamentally unlike its parent and must metamorphose | 8 | |
| 2255036310 | metamorphosis | the marked and rapid transformation of a larva into an adult that occurs in some animals | 9 | |
| 2255036311 | Ediacaran biota | An early group of soft-bodied, multicellular eukaryotes known from fossils that range in age from 565 million to 545 million years old. | 10 | |
| 2255036312 | 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 545 to 525 million years ago. | 11 | |
| 2255036313 | body plan | In animals, a set of morphological and developmental traits that are integrated into a functional whole—the living animal. | 12 | |
| 2255036314 | radial symmetry | body plan in which body parts repeat around the center of the body -- no sides, back, front - only has a top and bottom side | 13 | |
| 2255036315 | bilateral symmetry | the property of being symmetrical about a vertical plane - two sided symmetry | 14 | |
| 2255036316 | dorsal | top | 15 | |
| 2255036317 | ventral | bottom | 16 | |
| 2255036318 | anterior | front | 17 | |
| 2255036319 | posterior | back | 18 | |
| 2255036320 | cephalization | concentration of sense organs and nerve cells at the front of an animal's body - head development | 19 | |
| 2255036321 | endoderm | the inner germ layer that develops into the lining of the digestive and respiratory systems | 20 | |
| 2335005506 | endoderm formation | - epidermis of skin - epithelial lining of mouth and anus - cornea and lens of eye - nervous system | 21 | |
| 2255036322 | 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 | 22 | |
| 2335010290 | ectoderm formation | - skeletal system - muscular system - muscular layer of stomach and intestine - lining of body cavity - notochord | 23 | |
| 2255036323 | diploblastic | Having two germ layers. | 24 | |
| 2255036324 | mesoderm | the middle germ layer that develops into muscle and bone and cartilage and blood and connective tissue | 25 | |
| 2335015509 | mesoderm formation | - epithelial lining of digestive tract - epithelial lining of respiratory system - lining of urinary bladder and reproductive system - liver | 26 | |
| 2255036325 | triploblastic | Possessing three germ layers: the endoderm, mesoderm, and ectoderm. Most eumetazoans are triploblastic. | 27 | |
| 2255036326 | body cavity | A fluid or air-containing space between the digestive tract and the body wall. | 28 | |
| 2255036327 | coelom | body cavity lined by tissue on both sides, derived from mesoderm | 29 | |
| 2255036328 | coelomates | An animal that possesses a true coelom (a body cavity lined by tissue completely derived from mesoderm). - earthworm | 30 | |
| 2255036329 | pseudocoelomates | An animal whose body cavity is lined by tissue derived from mesoderm and endoderm. - roundworm | 31 | |
| 2255036330 | acoelomates | A solid-bodied animal lacking a cavity between the gut and outer body wall. - planarians | 32 | |
| 2255036331 | 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. | 33 | |
| 2255036332 | deuterostome development | animal whose anus is formed from the blastopore of a blastula | 34 | |
| 2255036333 | spiral cleavage | A type of embryonic development in protostomes, in which the planes of cell division are diagonal to the vertical axis of the embryo; smaller cells are centered over the grooves between larger, underlying cells. | 35 | |
| 2255036334 | determinate cleavage | A type of embryonic development in protostomes that rigidly casts the developmental fate of each embryonic cell very early. | 36 | |
| 2255036335 | blastopore | The opening of the archenteron in the gastrula that develops into the mouth in protostomes and the anus in deuterostomes | 37 | |
| 2255036336 | 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. | 38 | |
| 2255036337 | 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. | 39 | |
| 2255036338 | archenteron | The endoderm-lined cavity, formed during the gastrulation process, that develops into the digestive tract of an animal. | 40 | |
| 2255036339 | Protostome Development Cleavage | spiral and determinate | 41 | |
| 2255036340 | Deutrostome Development Cleavage | radial and indeterminate | 42 | |
| 2255036341 | Protosome Coelom Formation | solid masses of mesoderm split and form coelom | 43 | |
| 2255036342 | Deuterostome Coelom Formation | folds of archenteron form coelon | 44 | |
| 2255036343 | Protostome blastospore fate | mouth developments from blastopore | 45 | |
| 2255036344 | Deuterostome blastopore fate | anus develops from blastopore | 46 | |
| 2255036345 | eumetazoans | Member of a clade of animals with true tissues. | 47 | |
| 2255036346 | All animals share a... | common ancestor | 48 | |
| 2255036347 | Eumetazoa is a clade of animals with... | true tissues | 49 | |
| 2255036348 | Sponges are... | basal animals | 50 | |
| 2255036349 | Most animal phyla belong to the clade... | Bilateria | 51 | |
| 2255036350 | Chordates and some other phyla belong to the clade... | Deuterostomia | 52 | |
| 2255036351 | bilaterians | member of a clade of animals with bilateral symmetry and three germ layers. | 53 | |
| 2255036352 | ecdysozoans | Member of a group of animal phyla identified as a clade by molecular evidence. Many ecdysozoans are molting animals. | 54 | |
| 2255036353 | lophotrochozoans | refers to animals in the taxa who either develop a lophophore or go through the trochophore larva stage | 55 | |
| 2255036354 | lophophore | A horseshoe-shaped or circular fold of the body wall bearing ciliated tentacles that surround the mouth. | 56 | |
| 2255036355 | trochophore larva | Distinctive larval stage observed in some lophotrochozoan animals, including some annelids and molluscs. | 57 |
