Chapter 33 Flashcards
Describe the Phylum Porifera; give the clade and members of the phylum
Lack true tissues; have choanocytes (collar cells–flagellated cells that ingest bacteria and tiny food particles)
(sponges)
Basal group of the clade Metazoa
Describe the Phylum Cnidaria; give the clade and members of the phylum
Unique stinging structures (nematocytes) housed in specialized cells (cnidocytes); diploblastic; radially symmetrical; gastrovascular cavity (digestive compartment with a single opening)
(hydras, jellies, sea anemones, corals)
Oldest member of the clade Eumetazoa (tissued animals)
Describe the Phylum Platyhelminthes; give the clade and members of the phylum
Dorsoventrally flattened acoelomates; gastrovascular cavity or no digestive tract
(flatworms)
Part of the Bilaterian clade Lophotrochozoa
Describe the Phylum Rotifera; give the clade and members of the phylum
Pseudocoelomates with alimentary canal (digestive tube with mouth and anus); jaws (trophi); head with ciliated crown
(rotifers)
Part of the Bilaterian clade Lophotrochozoa
Describe the Phylum Lophophorates; give the clade and members of the phylum
Coelomates with lophophores (feeding structures bearing ciliated tentacles)
(Ectoprocta, Brachiopoda)
Part of the Bilaterian clade Lophotrochozoa
Describe the Phylum Mollusca; give the clade and members of the phylum
Coelomates with three main body parts (muscular foot, visceral mass, mantle); coelom reduced; most have hard shell made of calcium carbonate
(clams, snails, squids)
Part of the Bilaterian clade Lophotrochozoa
Describe the Phylum Annelida; give the clade and members of the phylum
Coelomates with segmented body wall and internal organs (except digestive tract, which is unsegmented)
(segmented worms)
Part of the Bilaterian clade Lophotrochozoa
Describe the Phylum Nematoda; give the clade and members of the phylum
Cylindrical pseudocoelomates with tapered ends; no circulatory system; undergo ecdysis (shedding)
(roundworms)
Part of the Bilaterian clade Ecdysozoa
Describe the Phylum Arthropoda; give the clade and the members of the phylum
Coelomates with segmented body, jointed appendages, and exoskeleton made of protein and chitin
(spiders, centipedes, crustaceans, and insects)
Part of the Bilaterian clade Ecdysozoa
Describe the Phylum Echinodermata; give the clade and members of the phylum
Coelomates with bilaterally symmetrical larvae and five-part body organization as adults; unique water vascular system; endoskeleton
(sea stars, sea urchins)
Part of the Bilaterian clade Deuterostomia
Describe the Phylum Chordata; give the clade and members of the phylum
Coelomates with notochord; dorsal, hollow nerve cord; pharyngeal slits; post-anal tail
(lancelets, tunicates, vertebrates)
Part of the Bilaterian clade Deuterostomia
What are the six phyla that make up the Lophotrochozoa clade?
Platyhelminthes, Rotifera, Ectoprocta, Brachiopoda, Mollusca, and Annelida
Describe the symmetry of platyhelminthes
bilateral with a distinct heat/tail and stereo senses
Describe any interesting developments the platyhelminthes made
developed a centralized nervous system
Describe the habitats of platyhelminthes
marine, freshwater, and damp terrestrial
Describe the tissues and body plan of platyhelminthes
triploblastic development, acoelomates
What characteristic are platyhelminthes named after? What advantage does this give?
Flattened shape-> aids in gas exchange and removes the need for a circulatory system
Describe the protonephridia of platyhelminthes
organs that regulate the osmotic balance
Describe the digestive system of platyhelminthes
Gastrovascular cavity with one opening, acoelomates
What are the four classes of platyhelminthes?
Monogenea, turbellaria, trematodes, cestoidea
What defines the Class Monogenea?
flatworms that are parasitic on fish gills
What defines the Class Turbellaria?
free-living flatworms
Name the class and describe the senses, nervous system, and reproduction of planarians
Class Turbellaria
Have light-sensitive eyespots and centralized nerve nets
Are hermaphrodites that can reproduce sexually or asexually (fission)
What are the members of the Class Trematodes called?
flukes
Describe the life cycle of schistosoma and name its class
Schistosoma releases its ciliated larva through the urine or feces of its infected human host, reproduces asexually in its snail intermediate host, leaves as a motile larva, and burrows into the skin of a human and travels to the blood vessels of the large intestine, small intestine, or bladder
Class Trematodes
Describe ‘swimmer’s itch’ and name the class of the organism that causes it
Swimmer’s itch is caused by a fish-eating-bird fluke that burrows into humans, but is repelled (hence the rash)
class trematodes
What are the members of the Class Cestoidea called?
Tapeworms
What are some of the innovations of the Class Cestoidea?
Lack a digestive system
Have hooks and/or sukers on their scolex
Self-fertilize to produce a chain of proglottids that will release fertilized eggs into the host’s digestive system
Describe the level of organization, digestive system, body plan, and general reproduction of rotifers
Specialized organ systems
Alimentary canal, mouth and anus (complete digestive system)
Pseudocoelomates
Reproduce by parthenogenesis
Of all the groups we study, which are acoelomates or pseudocoelomates?
A- flatworms
P- rotifers and roundworms
Describe the ectoprocts
Sessile colonial animals that resemble plants
Hard exoskeleton encases the colony, some species are reef builders
Describe the brachiopods. What group do they most closely resemble? How are they different?
Resemble clams, two halves are dorsal and ventral rather than lateral
Marine, attach to the seafloor by a stalk
Describe the general appearance and body organization of the clade Mollusca
Soft-bodied, most are protected by shells Have foot (mobility and food), visceral mass (house organs) , and mantle (secrete shell)
Describe the radula of the mollusca clade
rasplike organs used in feeding
What four classes make up the Mollusca clade?
Polyplacophora, gastropoda, bivalvia, and cephalopoda
Give the name and general description of the organisms in the class polyplacophora
chitons
Oval-shaped marine animals encased in an armor of 8 dorsal plates
What are some members of the class gastropoda?
Snails, slugs, nudibranches
What are three characteristics of the class gastropoda (movement, shell, feeding)?
Move by rippling foot/cilia
Most have a single, spiral shell
Most are herbivores
What are some members of the class bivalvia?
clams, mussels, oysters, scallops
Describe the habitat, shell, and feeding style of the class bivalia
Aquatic
Shell divided into 2 halves drawn together by adductor muscles
Mantle contains gills for feeding and gas exchange
What are some members of the class cephalopoda?
Octopus, squid, and nautilus
What are the two special things about the class cephalopoda?
closed circulatory system, only nautilus is shelled
Describe the general member of the class cephalopoda
Carnivores with beak-like jaws surrounded by tentacles of foot
Describe the life cycle of the mussels native to MO
Fertilization occurs within female
Trochophore larvae matures to veliger, a specialized kind of which (a glochidium) are released on to fish gills or fins (after luring with fake fish)
Develop there for days to weeks, then metamorphose into juveniles and fall to stream bottom
Give a few causes for the endangerment of the mussels native to MO
Button industry Habitat loss and fragmentation Dams and channelization Pollution and sedimentation Non-native species -> zebra mussel, Asiatic clam Loss of symbiotic fish species
Describe the innovations the annelids made in terms of organ systems, musculature, and ‘skeleton’
Closed circulatory system, complete digestive system, hydro-static skeleton, circular and longitudinal muscles
Describe the unique characteristics annelids have (symmetry, body organization, and structures)
segmented, bilateral symmetry, setae are bristles that aid in movement
Give an example of the benefits of the Class Oligochaeta
Earthworms eat through soil, passing it through their complete digestive system
Name some of the members of the Class Polychaeta
sandworms, lugworms, clam worms
What are the three classes that make up annelids?
Oligochaeta, polychaeta, hirundinea
What is the name for the members of class hirundinea?
Leeches
Give a few examples of the use of leeches in medicine
Secrete pain-killers and hirudin (anticoagulant) - research
Remove pooled blood
Help with reattached appendages
Help with reconstructive surgery
