| Term | Definition |
|---|
| triploblastic, acoelomate | The platyhelminths are a group of some 34000 describes species [with another 36500 awaiting description]; all of them are (diploblastic, triploblastic), (acoelomate, coelomate) and bilaterally symmetrical. |
| mesoderm | Platyhelminths are the first group to have evolved this germ layer. |
| lophotrochozoans | flatworms + molluscs + annelids + bryozoans + [some other phyla] = _____ |
| spiral, mouth, parenchyma | Flatworm development: _____ and determinate cleavage, with (mouth, anus) forming first; mesoderm develops into a loose collection of cells called _____ tissue |
| have no | Flatworms (have, have no) anus. |
| diffusion | Because they have no respiratory system, the mode of gas exchange in flatworms is by _____ across the body surface. |
| protonephridia, flame cells, solenocytes | Many flatworms contain a series of specialized organs for osmoregulation and excretion called _____, which may be in the form of either _____ [cells that appear to flicker; each consists of a group of cilia projecting into a fine-meshed cup] or _____ [single flagellum projects within the cup]. |
| simultaneous hermaphrodites | The vast majority of flatworms are _____ _____; that is, each individual can, at any one time, function as both a female and a male. |
| tegument | Except in Turbellaria, the larval epidermis is replaced at metamorphosis by a living, nonciliated, syncytial _____. |
| aquatic | Most turbellarians live in (terrestrial, aquatic) environments. |
| nerve net | type of nervous system in turbellarians |
| benthic | Most aquatic turbellarian species are _____; that is, they live in or on the ocean, lake, river or pond bottom. |
| mucus | Most turbellarians move at least partly by secreting _____from the ventral surface and beating the ventral cilia within it. |
| multiciliated | Each flatworm epidermal cell is (monociliated, multiciliated). |
| pedal waves | The locomotion of many turbellarians involves subtle waves of muscular contraction along the animal's ventral surface; these _____ are unidirectional, moving from the anterior of the worm posteriorly. |
| looping | pronounced movement of some turbellarians; individual attaches at the anterior end, pulls the posterior forward by contracting longitudinal muscles, attaches at the posterior end, releases the anterior end, and then thrusts the body forward by contracting circular muscles |
| duo-glands | paired secretory cells on the ventral surface of most flatworms, opening to the exterior; one cell produces a viscous glue while another secretes a chemical that breaks this attachment to the substrate |
| rhabdites, rhabdoids | The body surface of many turbellarians bears numerous aggregations of small cylindrical _____ and _____; these structures release a thick mucus that coats the animal's body, possibly in response to attempted predation or to dessication. |
| have no, have no | Acoel flatworms [order Acoela] (have, have no) mouth openings and (have, have no) well-formed gut cavities; in these turbellarians, food is essentially thrust into a densely packed mass of specialized digestive cells. |
| pharynx | The mouth of more advanced turbellarian species is often borne at the end of a protrusible _____; other species possess a separate proboscis that spears food items and then transfers them to an adjacent mouth opening. |
| extracellular | Initial mode of digestion of food in turbellarians: extracellular or intracellular? |
| 4, Polycladida | number of types of morphologies of digestive systems found in turbellarians; most have a three-branched gut but order _____ have a multibranched gut |
| hypodermic impregnation | Both male and female reproductive organs can be found within a single turbellarian; also, copulation in most species occurs via ____ ____, where the stylets of the penis pierce the body of the partner. |
| Muller's larva | microscopic free-swimming larval stage in some turbellarians |
| neoblasts | Regeneration in turbellarian species is accomplished through the activities of _____, undiffrentiated cells with very versatile developmental plasticity. |
| scolex, proglottids, absence | DC--Class Cestoda: small anterior hooked attachement organ called _____; division of body into _____ or segments arising from the anterior end behind the neck; (presence, absence) of digestive tract |
| endoparasitic, ectoparasitic | Parasitic activity of - cestodes and trematodes : _____ :: monogeneans : _____ |
| tegument | turbellarians : ciliated epidermis :: cestodes, monogeneans and trematodes : nonciliated _____ |
| syncytial | The tegument contains numerous nuclei, but these are not separated by cell membranes; that is, the tegument is _____. |
| scolex | anterior end of cestodes; studded with hooks and/or suckers that are used to maintain position within the gut of the host |
| Cestodaria | subclass of cestodes lacking a scolex |
| proglottids | endless series of sections in cestodes that bud from the next at a rate of several per day; each can produce up to 50000 eggs and is primarily involved in sexual reproduction |
| oncosphere | When a fertilized cestode egg is ingested by the appropriate intermediate host, an _____ larva commonly hatches out; it has muscles, flame cells and three pairs of hooks with which it attaches to the wall of the host's digestive tract. |
| cysticercus, hydatid cyst | After an oncosphere lyses and encysts in the coelom of the host, it produces a single resting individual called a _____; in select species, the resting stage divides asexually many times within the intermediate host to produce a large and sometimes deadly _____. |
| arthropods, molluscs | Intermediate hosts in - Cestoda : _____ :: Trematoda : _____ [general classification] |
| haptor, oncomiracidium | DC--Class Monogenea: posterior attachment organ called _____ including sucker and complex attachment hooks and sclerites; _____ larva bearing 3 bands of cilia and usually one to two pairs of eyes |
| host | Trematodes are most remarkable in contacting, recognizing and entering a new and appropriate _____. |
| bilobed | Trematodes have a mouth opening and a digestive tract that is, with a few exceptions, _____; the body is never segmented. |
| blood flukes | Schistosomiasis results from an infection by trematodes known as ____ ____; it is the second most prevalent disease in the world. |
| 1 | minimum number of intermediate hosts required by digenetic trematodes |
| miracidium, mother sporocyst, rediae, cercaria, metacercaria | Typical digenean life cycle: each fertilized egg gives rise to a single free-living ciliated ____ larva → larva ingested by IH then develops into a ____ while lives in the hemocoel → germ balls comprising the latter develop into ____ or daughter sporocysts → germ balls in each develops into an anatomically distinct larval stage, the ____ → latter leaves first IH, heads to second IH → upon encystment, enters waiting stage as a _____ where larval organs degenerate → second IH ingested by final host, adult trematode develops |
| snail | common mollusc which ingests miracidium larvae of digeneans |
| protonephridia | Miracidial structures are lost when developing into a mother sporocyst except the _____. [plural] |
| germ balls | structures which develop within each sporocyst or redia; responsible for geometric multiplication of offspring production after larval stages |
| tail | Free-swimming cercariae are nonciliated, but they can swim acitvely by means of a muscular _____. |
| detachment | Penetration by the cercaria larva into the next host is accompanied by the _____ of the cercarial tail. |
| suckers | Anterior and ventral _____ are present in digenean adults for maintaining position within the host. |
| proglottids | Cestodes achieve a high rate of offspring production by franchising egg and sperm manufacture and by adding on new franchisees, i.e. the _____. |
| Dicrocoelium dendriticum | liver fluke found in sheep and cattle; life cycle takes place entirely on land [s.n.] |
| snails, ants, grazers | Give the hosts of Dicrocoelium dendriticum in the following order: IH1, IH2, final host. [all plural] |
| septa | DC--Subclass Aspidogastrea: large ventral sucker divided by _____, generally forming a row of suckers |
| < | aspidogastreans ___ digeneans (host specificity) |
Combine with other sets
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