Invertebrates; 1100

Question 1

amoebocytes

Answer 1

specialized cells; disperse nutrients and oxygen to and collect waste from other cells of a sponge

Question 2

cnidarians

Answer 2

aquatic invertebrates; exhibit radial symmetry; exist as polyps at some point in their life cycles; tentacles with stinging cells

Question 3

ectoderm

Answer 3

outer cell layer of a cnidarian

Question 4

endoderm

Answer 4

inner cell layer of a cnidarian

Question 5

excurrent pore

Answer 5

single, large pore at the top if the sponge where water exits

Question 6

gastrovascular cavity

Answer 6

inner cavity of a cnidarian; responsible for breaking down food into nutrients

Question 7

incurrent pores

Answer 7

pores in the outer layer of a sponge; pull water in

Question 8

nematocyst

Answer 8

hollow, coiled, barb-tipped protein thread; discharges from a stinging cell of a cnidarian; releases toxin to paralyze the prey

Question 9

sponges

Answer 9

aquatic invertebrates; porous bodies; skeletons made of collagen or mineral fibers

Question 10

vacuoles

Answer 10

small, fluid-filled cavities within the endoderm; transport nutrients and oxygen to the cnidarians cells; remove waste products

Question 11

anus

Answer 11

excretes undigested food into the gastropod’s mantle cavity

Question 12

cerebral ganglia

Answer 12

nerve clusters; help a gastropod respond to certain stimuli

Question 13

crop

Answer 13

gastropod’s digestive organ; located between the mouth and the esophagus; enzymes and bacteria continue chemical digestion

Question 14

eyespots

Answer 14

cluster of optic receptors; located at the base of a snail’s tentacles or on the tips of its eyestalks

Question 15

gastropods

Answer 15

stomach-foot mollusks; large muscular foot below the stomach and other organs

Question 16

intestine

Answer 16

short, looped digestive organ; nutrients pass through its walls and are eventually circulated to all the cells of the gastropod

Question 17

mantle

Answer 17

think layer of epithelial cells; covers most of a gastropod’s dorsal side; secrets the building materials for the shell

Question 18

mollusks

Answer 18

invertebrates; soft bodies; internal organs inclosed by a mantle; include gastropods, bivalves, and cephalopods

Question 19

operculum

Answer 19

hard, protective flap; covers a snail’s shell opening

Question 20

radula

Answer 20

gastropod’s denticle-lined, muscular tonguelike organ

Question 21

visceral ganglia

Answer 21

nerve clusters; control the functions of a gastropod’s organs

Question 22

visceral mass

Answer 22

region where internal organs are located in a gastropod

Question 23

arm

Answer 23

cephalopod appendage; lined with suckers

Question 24

cephalopods

Answer 24

head-foot mollusk; octopuses, squids, nautiluses, argonauts, cuttlefish, and spirula

Question 25

chromatophores

Answer 25

epithelial cells; contain sacs of pigments and sacs of reflective particles; enable a cephalopod to change its skin color

Question 26

cuttlefish

Answer 26

cephalopod; 8 arms, 2 tentacles; internal shell structure resembling a long, flat bone made of calcium carbonate

Question 27

funnel

Answer 27

cephalopod’s excurrent siphon

Question 28

nautilus

Answer 28

cephalopod; up to 90 tentacles; true external shell

Question 29

octopus

Answer 29

cephalopod; 8 arms; no shell

Question 30

radula

Answer 30

denticle-lined, tongue-like organ of cephalopods

Question 31

rostrum

Answer 31

pair of hard, beaklike structures inside a cephalopod’s mouth; used to tear food into smaller pieces

Question 32

spirula

Answer 32

cephalopod; 8 arms, 2 tentacles; chambered internal shell

Question 33

squid

Answer 33

cephalopod; 8 arms, 2 tentacles; internal, leaf-shaped shell structure called a pen

Question 34

tentacle

Answer 34

cephalopod appendage; suckers only at its tip or no suckers

Question 35

ampulla

Answer 35

a bulb above each tube foot

Question 36

brittle star

Answer 36

echinoderm; long, thin arms lined with rows of short spines

Question 37

cardiac stomach

Answer 37

sea star’s first stomach; can be turned inside out to partially digest food outside of the sea star’s body

Question 38

echinoderm

Answer 38

marine invertebrates; hard, flat internal skeletons; water vascular systems; sea stars, brittle stars, and sea urchins

Question 39

madreporite

Answer 39

button-shaped pore on the dorsal side of a sea star; where water enters the water vascular system

Question 40

ossicles

Answer 40

flat, bony plates that form the skeleton of an echinoderm

Question 41

pyloric stomach

Answer 41

sea star’s second stomach; where partially digested food is distributed to each pyloric cecum

Question 42

sea cucumber

Answer 42

echinoderm; long, cylinder body; no arms; burrows into the mud and filters food out in the sediment

Question 43

sea lily

Answer 43

echinoderm; body and arms look like a brittle star; often remains to the sea floor using its stalk and tube feet

Question 44

sea urchin

Answer 44

echinoderm; flat bottom; a rounded upper body covered with fused ossicles and long, sharp spines

Question 45

skin gills

Answer 45

tiny bumps on the sea star’s skin; extract oxygen from water

Question 46

tube feet

Answer 46

tube-shaped structures on the ventral side of each arm of a sea star; used for locomotion and food gathering