Unit 2: Lesson 13- Annelids, Mollusks, and Echinoderms

Question 1

Phylum Annelida

Answer 1

Closed circulatory system, segmented worms, each segment has pair of setae (hairs)

Question 2

Class Polychaeta (Phylum Annelida)

Answer 2

Bristle/tube worms, parapodia contains setae

Question 3

Class Clitellata (Phylum Annelida)

Answer 3

Earthworms and leeches, has clitellum (reproductive unit)

Subclass Oligochaeta- earthworm, decomposer, eat dirt, benefit plants

Subclass Hirudinea- Leeches, predator/parasite, anesthetic and hirudin (anticoagulant) in saliva

Question 4

Ectoprocta (lophophore)

Answer 4

Sessile, colony, made of chitin

Question 4

Brachiopoda (lophophore)

Answer 4

Sessile, 2 shell halves, hide lophophore structure

Question 5

Phylum Mollusca

Answer 5

Bilateral, triploblastic, coelomate, open gut, soft-bodied, gills, 3 part body plan (muscular foot, mantle/shell, visceral mass), “lungs”

Question 6

Class Polyplacophora (Phylum Mollusca)

Answer 6

Chitons, 8 dorsal plates, grazers

Question 7

Class Gastropoda (Phylum Mollusca)

Answer 7

“stomach foot”, slugs/snails, 2 eye stalk tentacles, predators/grazers, 180 rotation of visceral mass along foot (torsion)

Question 8

Class Bivalva (Phylum Mollusca)

Answer 8

2 shell halves cover visceral mass, filter feeders (use siphons to feed), clams, muscles, oysters, scallops, parasitic glochidia larvae drink blood and live in fish gills (helps them to spread out since adults aren’t very mobile)

Question 9

Class Scaphopoda (Phylum Mollusca)

Answer 9

“tusk foot”, use siphons in a tubular shell

Question 10

Class Cephalopoda (Phylum Mollusca)

Answer 10

“head foot”, big brain, foot modified into tentacles, no shell (mostly), predators, have beak

Question 11

Phylum Echinodermata (Deuterostomia)

Answer 11

Bilateral, 5 rows of tube feet, triploblastic, coelomate, open gut, skin made of CaCO3, water vascular system

Question 12

Class Asteroidea (Phylum Echinodermata)

Answer 12

Sea stars, tube feet help with mobility, predators of clams

Question 13

Class Ophiuroidea (Phylum Echinodermata)

Answer 13

Brittle stars, scavengers, thin arms around central disk body

Question 14

Class Echinoidea (Phylum Echinodermata)

Answer 14

Sand dollars, sea urchin, eat algae with mouth called Aristotle’s Lantern

Question 15

Class Crinoidea (Phylum Echinodermata)

Answer 15

Sea lily (extinct), feather star, filter feeders

Question 16

Class Holothuroidea (Phylum Echinodermata)

Answer 16

Sea cucumbers, elongated body, filter feeder