KINGDOM: ___________________________
PHYLUM: ____________________________
CLASSES: 1. ______________________ 2. _________________ 3. __________________
1. Body is _________ dorsoventrally & ribbon-like without true _______________. Oral & genital
openings mostly on the ____________ surface.
2. _____________ symmetry; definite ____________ & ______________ ends.
3. Three layers of cells: ____________________, ________________, & _________________.
___________________ cavity present.
4. No true body cavity - _____________________.
5. No _____________, _________________, or _______________ systems. Oxygen & CO2 must diffuse across the body wall.
6. Nervous system composed of _______ longitudinal nerve cords.
7. Simple _____________ organs; __________ in some.
8. _____________ system of 2 lateral canals with branches bearing _________ cells (protonephridia).
9. Most forms ______________; reproductive system complex with well developed ________, ducts, and
accessory organs. _____________ fertilization.
CLASS TURBELLARIA – “a little stirring” - _________ cover exterior. Mostly free-living, few __________. Habitat - ___________ (mainly marine). _______________ present – secrete mucus for movement. Best example - ______________. These organisms have the ability to ___________ with a horizontal fission. Flat like a piece of tape.
CLASS TREMATODA – “pore resemblance” - _________ with _____ suckers. Best example - __________. ___________ present, no anal opening. ___________ present which helps prevent digestion from host. _________ sucker for feeding; _________ sucker for attachment (acetabulum – “little vinegar cup”). Nervous system poorly developed due to parasitic habits. Usually have one or more intermediate hosts. Many are endoparasites while others are ectoparasites. Flukes typically bore through skin & enter the bloodstream. These kill thousands of people each year.
CLASS CESTODA – “girdle form” - ____________ with a crown of hooks on the head - ______________ & suckers. Best example - _________________________.These are all ____________ parasites living in the adult stage in the _____________ of vertebrates & in the _________ stage in tissues of some alternate host. The body consists of a chain of segments called _______________ which increase in size from the anterior to the posterior end each year. These are also covered with a _____________. These contain no ________ or digestive system. Digested food in the intestine of the host is absorbed through the ___________ of the tapeworm.
The Platyhelminthes show relationship to the coelenterates below them especially in regard to the digestive tract with only one opening. The typical organization of the flatworm is best shown in the free-living turbellarians, since the trematodes & cestodes have become modified because of parasitic habits. The flatworms, as exhibited by the planarians, show definite phylogenetic advances over the lower phyla. For example, the central nervous system is more highly developed than the nerve-net; flatworms possess an excretory system; the mesodermal musculature is superior to that of the ectodermal & endodermal structures of the coelenterates; and the reproductive structures are vastly more elaborate.
PHYLUM: _______________________
1. Long Proboscis.
2. Flat body.
3. Acoelomates.
4. Simplest animals with 1-way digestive tract.
5. Circulatory system present.
Example = ribbon worms