Section 26 Vocab

Question 1

Cnidocyte

Answer 1

Stinging cell of cnidarians; used for defense and to capture prey

Question 2

Nematocyst

Answer 2

Stinging structure within each cnidocyte of a cnidarian that is used to poison or kill prey

Question 3

Polyp

Answer 3

Usually sessile stage of the life cycle of A cnidarian that has a cylindrical body with armoire tentacles

Question 4

Medusa

Answer 4

Motile stage of life cycle of a cnidarian that has a bell shaped body

Question 5

Gastrovascular cavity

Answer 5

Digestive chamber with a single opening, in which cnidarians, flatworms, and echinoderms digest food

Question 6

Nerve net

Answer 6

Loosely organized network of nerve cells that together allow cnidarians to detect stimuli

Question 7

Hydrostatic skeleton

Answer 7

Layers of circular longitudinal muscles, together with the water in the gastrovascular cavity, that enable movement

Question 8

External fertilization

Answer 8

Process in which eggs are fertilized outside the females body

Question 9

Invertebrate

Answer 9

Animal that does not have a backbone or vertebral column

Question 10

Vertebrate

Answer 10

Animal that has a vertebral column, or backbone

Question 11

Feedback inhibition

Answer 11

Process in which the product or result stops or limits the process

Question 12

Blastula

Answer 12

Hollow ball of cells formed when a zygote undergoes a series of divisons

Question 13

Protostome

Answer 13

Animal whose mouth is formed from its blastopore

Question 14

Deuterostome

Answer 14

Animal whose anus is formed from the blastopore of a Blastula

Question 15

Anus

Answer 15

Opening through which wastes leave the digestive tract

Question 16

Endoderm

Answer 16

Innermost germ layers of most animals; develops into the linings of the digestive tract and much of the respiratory system

Question 17

Ectoderm

Answer 17

Outermost germ layer of most animals; gives rise to outer layer of the skin, sense organs, and nerves

Question 18

Radial symmetry

Answer 18

Body play in which body parts repeat around the center of the body; characteristic of a sea anemones and sea stars

Question 19

Bilateral symmetry

Answer 19

Body plan in which only a single, imaginary line can divide the body into two equal halves; characteristics of worms, arthropods, and chordates

Question 20

Cephalization

Answer 20

Concentration of sense organs and nerve cells at the front of an animals body

Question 21

Choanocyte

Answer 21

Specialized cell in sponges that use a flagellum to move a steady current of water through the sponge

Question 22

Osculum

Answer 22

Large hole at the top of the sponge through which water leaves the sponge

Question 23

Spicule

Answer 23

Spike shaped structure that makes up the skeletons of harder sponges; made of either calcium carbonate or silica

Question 24

Archaeocyte

Answer 24

Specialized cell in a sponge that makes spicules

Question 25

Internal fertilization

Answer 25

Process in which eggs are fertilized inside the females body

Question 26

Larva

Answer 26

Immature stage of an organism that looks different from the adult form

Question 27

Gemmule

Answer 27

Group of archaeocytes surrounded by a tough layer of spicules; produced by some sponges