Chapter 33

Question 1

Describe the Phylum Porifera; give the clade and members of the phylum

Answer 1

Lack true tissues; have choanocytes (collar cells–flagellated cells that ingest bacteria and tiny food particles)
(sponges)
Basal group of the clade Metazoa

Question 2

Describe the Phylum Cnidaria; give the clade and members of the phylum

Answer 2

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)

Question 3

Describe the Phylum Platyhelminthes; give the clade and members of the phylum

Answer 3

Dorsoventrally flattened acoelomates; gastrovascular cavity or no digestive tract
(flatworms)
Part of the Bilaterian clade Lophotrochozoa

Question 4

Describe the Phylum Rotifera; give the clade and members of the phylum

Answer 4

Pseudocoelomates with alimentary canal (digestive tube with mouth and anus); jaws (trophi); head with ciliated crown
(rotifers)
Part of the Bilaterian clade Lophotrochozoa

Question 5

Describe the Phylum Lophophorates; give the clade and members of the phylum

Answer 5

Coelomates with lophophores (feeding structures bearing ciliated tentacles)
(Ectoprocta, Brachiopoda)
Part of the Bilaterian clade Lophotrochozoa

Question 6

Describe the Phylum Mollusca; give the clade and members of the phylum

Answer 6

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

Question 7

Describe the Phylum Annelida; give the clade and members of the phylum

Answer 7

Coelomates with segmented body wall and internal organs (except digestive tract, which is unsegmented)
(segmented worms)
Part of the Bilaterian clade Lophotrochozoa

Question 8

Describe the Phylum Nematoda; give the clade and members of the phylum

Answer 8

Cylindrical pseudocoelomates with tapered ends; no circulatory system; undergo ecdysis (shedding)
(roundworms)
Part of the Bilaterian clade Ecdysozoa

Question 9

Describe the Phylum Arthropoda; give the clade and the members of the phylum

Answer 9

Coelomates with segmented body, jointed appendages, and exoskeleton made of protein and chitin
(spiders, centipedes, crustaceans, and insects)
Part of the Bilaterian clade Ecdysozoa

Question 10

Describe the Phylum Echinodermata; give the clade and members of the phylum

Answer 10

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

Question 11

Describe the Phylum Chordata; give the clade and members of the phylum

Answer 11

Coelomates with notochord; dorsal, hollow nerve cord; pharyngeal slits; post-anal tail
(lancelets, tunicates, vertebrates)
Part of the Bilaterian clade Deuterostomia

Question 12

What are the six phyla that make up the Lophotrochozoa clade?

Answer 12

Platyhelminthes, Rotifera, Ectoprocta, Brachiopoda, Mollusca, and Annelida

Question 13

Describe the symmetry of platyhelminthes

Answer 13

bilateral with a distinct heat/tail and stereo senses

Question 14

Describe any interesting developments the platyhelminthes made

Answer 14

developed a centralized nervous system

Question 15

Describe the habitats of platyhelminthes

Answer 15

marine, freshwater, and damp terrestrial

Question 16

Describe the tissues and body plan of platyhelminthes

Answer 16

triploblastic development, acoelomates

Question 17

What characteristic are platyhelminthes named after? What advantage does this give?

Answer 17

Flattened shape-> aids in gas exchange and removes the need for a circulatory system

Question 18

Describe the protonephridia of platyhelminthes

Answer 18

organs that regulate the osmotic balance

Question 19

Describe the digestive system of platyhelminthes

Answer 19

Gastrovascular cavity with one opening, acoelomates

Question 20

What are the four classes of platyhelminthes?

Answer 20

Monogenea, turbellaria, trematodes, cestoidea

Question 21

What defines the Class Monogenea?

Answer 21

flatworms that are parasitic on fish gills

Question 22

What defines the Class Turbellaria?

Answer 22

free-living flatworms

Question 23

Name the class and describe the senses, nervous system, and reproduction of planarians

Answer 23

Class Turbellaria
Have light-sensitive eyespots and centralized nerve nets
Are hermaphrodites that can reproduce sexually or asexually (fission)

Question 24

What are the members of the Class Trematodes called?

Answer 24

flukes

Question 25

Describe the life cycle of schistosoma and name its class

Answer 25

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

Question 26

Describe 'swimmer's itch' and name the class of the organism that causes it

Answer 26

Swimmer’s itch is caused by a fish-eating-bird fluke that burrows into humans, but is repelled (hence the rash) class trematodes

Question 27

What are the members of the Class Cestoidea called?

Answer 27

Tapeworms

Question 28

What are some of the innovations of the Class Cestoidea?

Answer 28

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

Question 29

Describe the level of organization, digestive system, body plan, and general reproduction of rotifers

Answer 29

Specialized organ systems Alimentary canal, mouth and anus (complete digestive system) Pseudocoelomates Reproduce by parthenogenesis

Question 30

Of all the groups we study, which are acoelomates or pseudocoelomates?

Answer 30

A- flatworms | P- rotifers and roundworms

Question 31

Describe the ectoprocts

Answer 31

Sessile colonial animals that resemble plants | Hard exoskeleton encases the colony, some species are reef builders

Question 32

Describe the brachiopods. What group do they most closely resemble? How are they different?

Answer 32

Resemble clams, two halves are dorsal and ventral rather than lateral Marine, attach to the seafloor by a stalk

Question 33

Describe the general appearance and body organization of the clade Mollusca

Answer 33

``` Soft-bodied, most are protected by shells Have foot (mobility and food), visceral mass (house organs) , and mantle (secrete shell) ```

Question 34

Describe the radula of the mollusca clade

Answer 34

rasplike organs used in feeding

Question 35

What four classes make up the Mollusca clade?

Answer 35

Polyplacophora, gastropoda, bivalvia, and cephalopoda

Question 36

Give the name and general description of the organisms in the class polyplacophora

Answer 36

chitons | Oval-shaped marine animals encased in an armor of 8 dorsal plates

Question 37

What are some members of the class gastropoda?

Answer 37

Snails, slugs, nudibranches

Question 38

What are three characteristics of the class gastropoda (movement, shell, feeding)?

Answer 38

Move by rippling foot/cilia Most have a single, spiral shell Most are herbivores

Question 39

What are some members of the class bivalvia?

Answer 39

clams, mussels, oysters, scallops

Question 40

Describe the habitat, shell, and feeding style of the class bivalia

Answer 40

Aquatic Shell divided into 2 halves drawn together by adductor muscles Mantle contains gills for feeding and gas exchange

Question 41

What are some members of the class cephalopoda?

Answer 41

Octopus, squid, and nautilus

Question 42

What are the two special things about the class cephalopoda?

Answer 42

closed circulatory system, only nautilus is shelled

Question 43

Describe the general member of the class cephalopoda

Answer 43

Carnivores with beak-like jaws surrounded by tentacles of foot

Question 44

Describe the life cycle of the mussels native to MO

Answer 44

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

Question 45

Give a few causes for the endangerment of the mussels native to MO

Answer 45

``` Button industry Habitat loss and fragmentation Dams and channelization Pollution and sedimentation Non-native species -> zebra mussel, Asiatic clam Loss of symbiotic fish species ```

Question 46

Describe the innovations the annelids made in terms of organ systems, musculature, and 'skeleton'

Answer 46

Closed circulatory system, complete digestive system, hydro-static skeleton, circular and longitudinal muscles

Question 47

Describe the unique characteristics annelids have (symmetry, body organization, and structures)

Answer 47

segmented, bilateral symmetry, setae are bristles that aid in movement

Question 48

Give an example of the benefits of the Class Oligochaeta

Answer 48

Earthworms eat through soil, passing it through their complete digestive system

Question 49

Name some of the members of the Class Polychaeta

Answer 49

sandworms, lugworms, clam worms

Question 50

What are the three classes that make up annelids?

Answer 50

Oligochaeta, polychaeta, hirundinea

Question 51

What is the name for the members of class hirundinea?

Answer 51

Leeches

Question 52

Give a few examples of the use of leeches in medicine

Answer 52

Secrete pain-killers and hirudin (anticoagulant) - research Remove pooled blood Help with reattached appendages Help with reconstructive surgery