Lesson 21 Terms

Question 1

Ampulla

Answer 1

Muscle structures on the internal side of tube feet

Question 2

Anthozoa

Answer 2

sea anemones and corals

Question 3

Class Asteroidea

Answer 3

sea stars

Question 4

Class Echinoidea

Answer 4

sea urchins and sand dollars

Question 5

Class Holothuroidea

Answer 5

sea cucumbers

Question 6

Class Ophiuroidea

Answer 6

brittle stars

Question 7

Cnidocytes

Answer 7

stinging cells on tentacles

Question 8

Contractile cells

Answer 8

bend the organism’s body allowing it to move through the water

Question 9

Coral

Answer 9

colonial creatures: each coral is an individual multicellular organism, but they form a colony that’s interdependent on one another

Question 10

Epithelium

Answer 10

contains nerve cells and contractile cells

Question 11

Endoskeleton

Answer 11

an internal skeleton made up of plates called ossicles

Question 12

Class Hydrozoa

Answer 12

hydra, hydroid colonies, and the Portuguese Man-of-War

Question 13

Lateral canals

Answer 13

branch perpendicularly off the radial canals and terminate at tube feet

Question 14

Medusa

Answer 14

a) umbrella shaped body with its mouth facing downward and tentacles extending around it
b) Motile

Question 15

Mesoglea

Answer 15

A jelly-like substance between the inner layer and outer layer of cells in a cnidarian

Question 16

Nematocysts

Answer 16

coiled tubes containing an attached barb that discharges a toxin when launched

Question 17

Ossicles

Answer 17

plates that make up the endoskeleton

Question 18

Papulae

Answer 18

tubular extensions that assist in gas exchange

Question 19

Pentaradial symmetry

Answer 19

have 5 arms evenly distributed around a central disc

Question 20

Phylum Echinodermata

Answer 20

sea stars and sea urchins

Question 21

a) cup-shaped tubular body form with a mouth and tentacles at one end, and a base that attaches to a hard surface on the other end
b) Sessile

Answer 21

Polyp

Question 22

Radial canals

Answer 22

extend from central part of the echinoderm’s body down each ray

Question 23

Ring canal

Answer 23

where water enters, surrounding the mouth

Question 24

Class Scyphozoa

Answer 24

jellyfish

Question 25

Sieve plate

Answer 25

filters sea water before it enters the system

Question 26

Symbiotic

Answer 26

relationships with certain organisms where both organisms benefit from one another

Question 27

Symbiotic

Answer 27

relationships with certain organisms where both organisms benefit from one another

Question 28

Tube feet

Answer 28

hollow feet-like knobs

Question 29

Water vascular system

Answer 29

a system of tubes filled with water extending through their entire body