Term
| how are platyhelminthes recognized? |
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Definition
| called flatworms, they have a dorsoventrally flattened body. |
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Term
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Definition
| organisms that have a third major tissue layer, the mesoderm, that develops between the embryological ectoderm and endoderm. |
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Term
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Definition
-flattened bodies
-triploblastic
-have a recognizable head and tail
-bilaterally symmetrical
-lack a body cavity...acoelomates
-well developed nervous, excretory, muscular, and digestive systems
-have the organ-system level of complexity
-incomplete digestive tract because only has one opening for both mouth and anus
-some parasitic organisms live in their hosts' gut and absorb their nutrients; these organisms compeltely lack a digestive tract |
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Term
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Definition
| organisms that lack a body cavity between the gut and the outer body wall |
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Term
| the three classes of platyhelminthes we'll look at? |
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Definition
-turbellaria
-trematoda
-cestoda |
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Term
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Definition
-free living
-ventral mouth (usually)
-undivided body
-no larval stage; direct development |
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Term
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Definition
-parasitic
-usually anterior mouth
-undivided body
-one or more suckers for attachment within their host |
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Term
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Definition
-internal parasites; most inhabit the body of a vertebrate during some point of their life cycle
-no digestive tract in adults
-body usually divided into segments each of which contains a compelte reproductive system
-usually have an anterior scolex for attachment |
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Term
| an example of turbellaria |
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Definition
-planarians are a type
-move by ciliary-nucus mechanism
-ventral side covered by cilia
-have small glands that secrete a mucus lubricant that helps them glide |
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Term
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Definition
| covers the outside of the body of planarians. it is composed of cuboidal cells and interspersed unicellular glands secreting mucus or adhesives. |
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Term
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Definition
| the large columnar cells that line the gut. these are derivevd from endoderm |
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Term
| what is the tissue between the gastrodermis and muscle layers filled with? |
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Definition
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Term
| what are flukes a type of? |
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Definition
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Term
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Definition
| have at least one sucker surrounding their mouth which keeps them from losing their position within their host. they have a tough epidermis that keeps them from being digested by their host. some have larval stages where they live in one or more species of intermediate host and an adult stage in a different species. they have a two-branched intestine. |
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Term
| what in trematodes leads to an intestine? |
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Definition
| a muscular pharynx and a short esophagus lead to a two-branched intestine. |
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Term
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Definition
| a dark-staining structure that spread through most of the bosy of a trematode just posterior to the ventral sucker. |
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Term
| where is the ovary in trematodes? |
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Definition
| the single ovary is near the midline of the body and just posterior to the uterus. |
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Term
| how do ova pass in trematodes? |
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Definition
| ova pass from the ovary, through the uterus and exit through a small genital pore anterior to the ventral sucker. |
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Term
| where are testes in trematodes? |
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Definition
| the testes spread throughout most of the posterior one-fourth of the body posterior to the ovary. ducts lead from the testes to the genital pore. |
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Term
| trematodes can be of what sex? |
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Definition
| they are hermaphrodites but most cross-fertilize so that the sperm of one fertilizes the ova of another. |
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Term
| common name for class cestoda? |
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Definition
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Term
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Definition
| adults live in the digestive tract of some vertebrae (definitive host) while the larva lives in the tissues of some other animal(the intermediate host), the definitive host feeds on the intermediate host, ingesting the tapeworm's larva. |
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Term
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Definition
| knob-like segment of a tapeworm that bears suckers and hooks to hold on to. |
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Term
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Definition
| the segments of tapeworms which form the transverse budding in the neck region which contain flame cells, longitudinal nerve cords, and reproduction. the male reproductive organs mature first. the proglottids are eventually released from the digestive tract through the feces. |
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Term
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Definition
| organs of excretion, held by the proglottids |
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Term
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Definition
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Term
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Definition
| carries the sperm from the testes to the genital pore near the center of the proglottid |
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Term
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Definition
-commonly called round worms because of their nearly-circular cross section
-have a complete digestive tract
-one of their major adaptations is their cuticle, excreted by the epidermis |
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Term
| why are the cross sections of nematodes circular? |
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Definition
because they hold in so much pressure that their sides bulge in all directions
-some are freeliving while some are parasitic
-bilaterally symmetric and tripoblastic |
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Term
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Definition
| the cavity found in a tube within a tube body form. it is found between the wall of the gut and the body wall. it functions in the circulation and distribution of material throughout the body and as a hydrostatic skeleton functioning in locomotion. |
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Term
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Definition
| there is an anus separate from a mouth and food travels through a tract in only one direction. |
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Term
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Definition
| leads to the ejaculatory duct. the testis leads to a sperm duct which leads to the seminal vessel which leads to the ejaculatory duct which leads to the genital pore. |
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Term
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Definition
-commonly referred to as segmented worms because their bodies are divided both internally and externally into similar segments.
-the margins of segments are often marked by small grooves, annuli
-septa are the walls that separate segments
-they are bilaterally symmetrical, tripoblastic protosomes with compelte digestive tracts and closed circulatory systems
-most have small bristles called setae that function in locomotion or in holding the animal in place
-annelida has three classes: polychaeta, oligochaeta, and hirudinea |
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Term
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Definition
-have a collar called a clitellum
-secretes a cocoon tht protects the eggs until they hatch.
-prostomium overhags the mouth at the anterior
-has male and female genital pores
-seminal recepticles have openings
-hermaphroditic but not self-fertilizing
-have a coelum that contains organs and is divided by septa
-typhosole is a tissue that extends into the gut from the dorsal side
-the pharynx leads to the esophagus which is sorta hidden by whitish seminal vesicles
-esophagus leads to the think-walled crop which connectrs to the thick-walled gizzard
-cerebral ganglia= the brain
-circumpharyngeal connectives meet at the supharyngeal ganglion just beneath the pharynx.
-ventral nerve cord= two cords fused together
-dorsal blood vessel connects with five pairs of pumping vessels which conect to the esophagus to form the ventral blood vessel
-nephridia are in each segment to filter waste from the coelomic fluid and transfer it to the nepridiopores |
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Term
| describe class poloychaeta |
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Definition
-largest number of species of annelids
-most are marine and live in burrows
-"feather duster" tube worms are in this class
-setae are located on paddle-like parapodia |
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Term
| describe class hirundinea |
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Definition
-leeches are an example of hirundinea
-leeches have suckers used for attachment |
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