Chapter 18 Pt 1

Question 1

An amoeba-like cell that moves by pseudopodia, found in most animals; depending on the species, may digest and distribute food, dispose of wastes, form skeletal fibers, fight infections, and change into other cell types.

Answer 1

Amoebocyte

Question 2

A segmented worm. These organisms include earthworms, polychaetes, and leeches.

Answer 2

Annelid

Question 3

Pertaining to the front, or head, of a bilaterally symmetrical animal.

Answer 3

Anterior

Question 4

A member of a major arthropod group (chelicerates) that includes spiders, scorpions, ticks, and mites.

Answer 4

Arachnid

Question 5

A member of the most diverse phylum in the animal kingdom. These members are characterized by a chitinous exoskeleton, molting, jointed appendages, and a body formed of distinct groups of segments.

Answer 5

Arthropod

Question 6

An arrangement of body parts such that an organism can be divided equally by a single cut passing longitudinally through it. This organism has mirror-image right and left sides.

Answer 6

Bilateral symmetry

Question 7

Member of the clade of animals Bilateria exhibiting bilateral symmetry

Answer 7

Bilaterian

Question 8

A member of a group of molluscs that includes clams, mussels, scallops, and oysters

Answer 8

Bivalve

Question 9

An embryonic stage that marks the end of cleavage during animal development; a hollow ball of cells in many species.

Answer 9

Blastula

Question 10

A fluid-containing space between the digestive tract and the body wall.

Answer 10

Body Cavity

Question 11

A carnivorous terrestrial arthropod that has one pair of long legs for each of its numerous body segments, with the front pair modified as poison claws.

Answer 11

Centipede

Question 12

A member of a group of molluscs that includes squids and octopuses.

Answer 12

Cephalopod

Question 13

The transformation of a larva into an adult.

Answer 13

Metamorphosis

Question 14

A terrestrial arthropod that has two pairs of short legs for each of its numerous body segments and that eats decaying plant matter.

Answer 14

Millipede

Question 15

A soft-bodied animal characterized by a muscular foot, mantle, mantle cavity, and radula; includes gastropods (snails and slugs), bivalves (clams, oysters, and scallops), and cephalopods (squids and octopuses).

Answer 15

Mollusca

Question 16

The process of shedding an old exoskeleton or cuticle and secreting a new, larger one.

Answer 16

Molting

Question 17

A roundworm, characterized by a pseudocoelom, a cylindrical, wormlike body form, and a tough cuticle.

Answer 17

Nematode

Question 18

A flexible, cartilage-like, longitudinal rod located between the digestive tract and nerve cord in chordate animals; present only in embryos in many species.

Answer 18

Notochord

Question 19

A circulatory system in which blood is pumped through open-ended vessels and bathes the tissues and organs directly. In an animal with this system, blood and interstitial fluid are one and the same.

Answer 19

Open Circulatory System

Question 20

Structures found in the pharynx; found in chordate embryos and some adult chordates.

Answer 20

Pharyngeal gill slits

Question 21

A member of the largest group of annelids.

Answer 21

Polychaetes

Question 22

One of two types of cnidarian body forms; a columnar, hydra-like body.

Answer 22

Polyp

Question 23

A tail posterior to the anus; found in chordate embryos and most adult chordates

Answer 23

Post-anal tail

Question 24

Pertaining to the rear, or tail, of a bilaterally symmetrical animal

Answer 24

Posterior

Question 25

An animal with a coelom that develops from solid masses of cells that arise between the digestive tube and the body wall of the embryo. These animals include the molluscs, annelids, and arthropods.

Answer 25

Protostome

Question 26

A body cavity that is in direct contact with the wall of the digestive tract.

Answer 26

Pseudocoelom

Question 27

An arrangement of the body parts of an organism like pieces of a pie around an imaginary central axis. Any slice passing longitudinally along the organism's central axis divides it into mirror-image halves.

Answer 27

Radial symmetry

Question 28

A toothed, rasping organ used to scrape up or shred food; found in many molluscs.

Answer 28

Radula

Question 29

Subdivision along the length of an animal body into a series of repeated parts called segments.

Answer 29

Segmentation

Question 30

An organism that is anchored to its substrate.

Answer 30

Sessile

Question 31

An aquatic animal characterized by a highly porous body.

Answer 31

Sponge

Question 32

An aquatic animal that sifts small food particles from the water

Answer 32

Suspension feeder

Question 33

A parasitic flatworm characterized by the absence of a digestive tract.

Answer 33

Tapeworms

Question 34

One of a group of invertebrate chordates.

Answer 34

Tunicate

Question 35

Pertaining to the underside, or bottom, of a bilaterally symmetrical animal.

Answer 35

Ventral

Question 36

One of the three main parts of a mollusc, containing most of the internal organs.

Answer 36

Visceral mass

Question 37

In echinoderms, a radially arranged system of water-filled canals that branch into extensions called tube feet. The system provides movement and circulates water, facilitating gas exchange and waste disposal.

Answer 37

Water Vascular System