Biology Cambell Ch 33

Front 1

Annelids

Back 1

segmented worms

Front 2

alimentary canal

Back 2

A digestive tract consisting of a tube running between a mouth and an anus.

Front 3

amoebocyte

Back 3

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.

Front 4

Bivalvia

Back 4

(clams and their relatives) have a hinged shell divided into two halves.

Front 5

book lung

Back 5

An organ of gas exchange in spiders, consisting of stacked plates contained in an internal chamber.

Front 6

Cephalopoda

Back 6

includes squids and octopuses, carnivores with beak–like jaws surrounded by tentacles of their modified foot.

Front 7

Cheliceriforms

Back 7

include spiders, ticks, and mites. They have an anterior cephalothorax and a posterior abdomen. The most anterior appendages are modified as chelicerae (either pincers or fangs).

Front 8

Class Anthozoa

Back 8

contains the sea anemones and corals, which occur only as polyps.

Front 9

Class Cestoda

Back 9

tapeworms, all of which are parasites and lack a digestive tract.

Front 10

Class Hydrozoa

Back 10

usually alternates polyp and medusa forms, although the polyp is more conspicuous.

Front 11

Class Polyplacophora

Back 11

composed of the chitons, oval–shaped marine animals encased in an armor of eight dorsal plates.

Front 12

Class Scyphozoa

Back 12

jellies (medusae) are the prevalent form of the life cycle.

Front 13

Class Turbellaria

Back 13

made up of mostly free–living, primarily marine species.

Front 14

Cnidarians

Back 14

mainly marine carnivores possessing tentacles armed with cnidocytes that aid in defense and the capture of prey. Two body forms are sessile polyps and floating medusae.

Front 15

chelicera

Back 15

One of a pair of clawlike feeding appendages characteristic of cheliceriforms.

Front 16

cheliceriform

Back 16

An arthropod that has chelicerae, and a body divided into a cephalothorax and an abdomen. Living cheliceriforms include sea spiders, horseshoe crabs, scorpions, ticks, and spiders.

Front 17

choanocyte

Back 17

A flagellated feeding cell found in sponges. Also called a collar cell, it has a collar-like ring that traps food particles around the base of its flagellum.

Front 18

class Gastropoda

Back 18

the snails and their relatives, possess a single, spiraled shell. Embryonic torsion of the body is a distinctive characteristic. Many slugs lack a shell or have a reduced shell.

Front 19

class Hirudinea

Back 19

bloodsucking parasites...leeches

Front 20

class Polychaeta

Back 20

possess paddle–like parapodia that function as gills and aid in locomotion.

Front 21

cnidocyte

Back 21

A specialized cell for which the phylum Cnidaria is named; contains a capsule containing a fine coiled thread, which, when discharged, functions in defense and prey capture.

Front 22

decapod

Back 22

A member of the group of crustaceans that includes lobsters, crayfish, crabs, and shrimps.

Front 23

Echinoderms

Back 23

(sea stars and their relatives) have a water vascular system ending in tube feet used for locomotion and feeding. The radial anatomy of many species evolved secondarily from the bilateral symmetry of ancestors. A thin, bumpy, or spiny skin covers a calcareous endo–skeleton.

Front 24

exoskeleton

Back 24

A hard encasement on the surface of an animal, such as the shell of a mollusc or the cuticle of an arthropod, that provides protection and points of attachment for muscles.

Front 25

Flatworms

Back 25

dorsoventrally flattened animals with a gastrovascular cavity.

Front 26

General Characteristics of Arthropods

Back 26

Variation in arthropod morphology consists mainly in specializations of groups of segments and in appendages. The arthropod exoskeleton, made of protein and chitin, undergoes regular ecdysis (molting).

Front 27

gastrovascular cavity

Back 27

An extensive pouch that serves as the site of extracellular digestion and a passageway to disperse materials throughout most of an animal’s body.

Front 28

hermaphrodite

Back 28

An individual that functions as both male and female in sexual reproduction by producing both sperm and eggs.

Front 29

Insects

Back 29

exceed all other animals combined in species diversity. Flight has been an important factor in the success of this group

Front 30

Lophophorates

Back 30

coelomates that have a lophophore, a horseshoe–shaped, suspension–feeding organ bearing ciliated tentacles.

Front 31

Molluscs

Back 31

have a muscular foot, a visceral mass, and a mantle

Front 32

Myriapods

Back 32

Millipedes are wormlike, with a large number of walking legs. They were among the first animals to live on land. Centipedes are terrestrial carnivores with poison claws.

Front 33

mantle cavity

Back 33

A water-filled chamber that houses the gills, anus, and excretory pores of a mollusc.

Front 34

medusa

Back 34

The floating, flattened, mouth-down version of the cnidarian body plan. The alternate form is the polyp.

Front 35

mesohyl

Back 35

A gelatinous region between the two layers of cells of a sponge.

Front 36

Nematodes

Back 36

nonsegmented pseudocoelomates covered by a tough cuticle. whip-like motion due to longitudinal muscles only

Front 37

Nemerteans

Back 37

have a unique retractable tube (proboscis) used for defense and prey capture. A fluid–filled sac is used to extend the proboscis.

Front 38

nematocyst

Back 38

A stinging, capsule-like organelle in a cnidocyte.

Front 39

Oligochaeta

Back 39

includes earthworms and various aquatic species.

Front 40

open circulatory system

Back 40

A circulatory system in which fluid called hemolymph bathes the tissues and organs directly and there is no distinction between the circulating fluid and the interstitial fluid.

Front 41

osculum

Back 41

A large opening in a sponge that connects the spongocoel to the environment.

Front 42

parthenogenesis

Back 42

A type of reproduction in which females produce offspring from unfertilized eggs.

Front 43

planarian

Back 43

A free-living flatworm found in unpolluted ponds and streams.

Front 44

polyp

Back 44

The sessile variant of the cnidarian body plan. The alternate form is the medusa.

Front 45

Rotifers

Back 45

Found mainly in fresh water, many rotifer species are parthenogenetic.

Front 46

radula

Back 46

A straplike rasping organ used by many molluscs during feeding.

Front 47

Sponges

Back 47

lack true tissues and organs. They suspension feed by drawing water through pores; choanocytes (flagellated collar cells) ingest suspended food.

Front 48

spongocoel

Back 48

The central cavity of a sponge.

Front 49

suspension feeder

Back 49

An aquatic animal, such as a clam or a baleen whale, that sifts small food particles from the water.

Front 50

Trematoda

Back 50

live as parasites in or on animals...Flukes

Front 51

trilobite

Back 51

An extinct arthropod with pronounced segmentation and appendages that varied little from segment to segment.

Front 52

trochophore larva

Back 52

Distinctive larval stage observed in certain invertebrates, including some annelids and molluscs.

Front 53

tube foot

Back 53

One of numerous extensions of an echinoderm’s water vascular system. Tube feet function in locomotion, feeding, and gas exchange.

Front 54

visceral mass

Back 54

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

Front 55

water vascular system

Back 55

A network of hydraulic canals unique to echinoderms that branches into extensions called tube feet, which function in locomotion, feeding, and gas exchange.

Front 56

mantle

Back 56

A fold of tissue in molluscs that drapes over the visceral mass and may secrete a shell.

Front 57

torsion

Back 57

A characteristic of gastropods in which the visceral mass rotates during development.

Front 58

arthropod

Back 58

A segmented coelomate with a chitinous exoskeleton, jointed appendages, and a body formed of distinct groups of segments.

Front 59

molting

Back 59

A process in arthropods in which the exoskeleton is shed at intervals, allowing growth by the production of a larger exoskeleton.

Front 60

crustacean

Back 60

A member of a subphylum of arthropods that includes lobsters, crayfish, crabs, shrimps, and barnacles

Front 61

isopod

Back 61

A member of one of the largest groups of crustaceans, which includes terrestrial, freshwater, and marine species. Among the terrestrial isopods are the pill bugs, or wood lice.

Front 62

copepod

Back 62

Any of a group of small crustaceans that are important members of marine and freshwater plankton communities.