Annelids

Question 1

True or False: Phylum Annelida largely consists of segmented worms

Answer 1

True

Question 2

Some ____ are grotesque in appearance, whereas others are graceful and beautiful.

Answer 2

polychaetes

Question 3

Segments of the bodies of most Annelids are ___

Answer 3

metameres

Question 4

Circular rings that externally mark metameres

Answer 4

annuli

Question 5

Division of the body into a series of units, each of which contains similar components of all major organ systems.

Answer 5

metamerism

Question 6

In annelids the segments are delimited internally by ___

Answer 6

Septa

Question 7

Annelids are sometimes called _____ because, with the exception of leeches, most annelids bear tiny chitinous bristles called setae

Answer 7

Bristle worms

Question 8

Short, needlelike setae help anchor segments during ____ and long, hairlike setae aid ____

Answer 8

locomotion; aquatic forms in swimming

Question 9

_____ are chiefly marine formd

Answer 9

Polychaetes

Question 10

Oligochaetes and leeches occur predominantly in _____

Answer 10

freshwater or terrestrial soils.

Question 11

Many leeches are predators, specialized for _____

Answer 11

piercing their prey and feeding on blood or soft tissues.

Question 12

A few leeches are _____, but most live in ____ or in damp regions.

Answer 12

marine; freshwater

Question 13

____ are typically found at both ends of the body for attachment to the substratum or to their prey

Answer 13

Suckers

Question 14

Composes the two-part head of the Annelid body

Answer 14

Prostomium and peristomium

Question 15

A terminal portion in the annelid body that bears an anus

Answer 15

pygidium

Question 16

New segments differentiate during development just in front of the _____

Answer 16

pygidium

Question 17

Te oldest segments are at the ____ end and the youngest segments are at the ____ end.

Answer 17

Anterior; posterior

Question 18

True or False: Each segment typically contains respiratory, nervous, and excretory structures, as well as a coelom.

Answer 18

True

Question 19

True or False: Flaps called parapodia may be present on each segment.

Answer 19

True

Question 20

lines the body wall of each compartment, forming dorsal and ventral mesenteries that cover all organs

Answer 20

Peritoneum

Question 21

Peritonea of adjacent segments meet to form ___, which are perforated by the gut and longitudinal blood vessels

Answer 21

Septa

Question 22

True or False: The body wall surrounding the peritoneum and coelom contains strong circular and longitudinal muscles adapted for swimming, crawling, and burrowing

Answer 22

True

Question 23

The coelom of most annelids is filled with fluid and serves as a hydrostatic skeleton except in ____.

Answer 23

Leeches

Question 24

Crawling motions are produced by ______

Answer 24

alternating waves of contraction by longitudinal and circular muscles passing down the body

Question 25

Swimming forms use ____ rather than peristaltic movements in locomotion.

Answer 25

undulatory

Question 26

An annelid body has a thin outer layer of ____ surrounding the epidermis

Answer 26

nonchitinous cuticle

Question 27

_____ are ancestral for annelids, although they have been reduced or lost in some.

Answer 27

Paired epidermal setae

Question 28

True or False: The annelid digestive system is segmented

Answer 28

False; the gut runs the length of the body perforating each septum

Question 29

True or False: Longitudinal dorsal and ventral blood vessels follow the same path, as does the ventral nerve cord

Answer 29

True

Question 30

Historically, annelids were divided among three classes: ____, ____, and ____.

Answer 30

Polychaeta, Oligochaeta, Hirudinida

Question 31

Phylogenetic analyses show polychaetes and oligochaetes to be ___ groups; leeches form a ___.

Answer 31

paraphyletic; clade

Question 32

Clitellata are characterized by presence of a reproductive structure called a ____

Answer 32

clitellum

Question 33

a term used to denote any of 80 morphologically distinct families of worms, typically those with many setae

Answer 33

Polychaete

Question 34

The division of annelids into two such groups, one ___ and the other ___ was proposed long ago on morphological grounds and later rejected.

Answer 34

Errant; Sedentary

Question 35

Differentiate Errant and Sedentary

Answer 35

Spelling; Errant (freely moving); Sedentary (spending most of their lives in tubes or burrows)

Question 36

Consists of about 250 species of benthic marine worms, living at depths ranging from the intertidal to more than 5000 m.

Answer 36

Sipuncula

Question 37

True or False: Sipuncula live sedentary lives in burrows in mud or sand, occupy borrowed snail shells, or live in coral crevices or among vegetation. 

Answer 37

True

Question 38

Some Sipuncula are commonly called ____ because, when disturbed, they can contract to a peanut shape

Answer 38

Peanut worms

Question 39

Sex cells are released in Sipuncula through the ____.

Answer 39

nephridia

Question 40

The larval form of Sipuncula is usually a ____

Answer 40

trochophore

Question 41

Members of _____ are unusual tube-dwelling annelids with three distinct body regions

Answer 41

Chaetopteridae

Question 42

The parchment worm, Chaetopterus feeds on ____

Answer 42

suspended particles

Question 43

(Chaetopteridae) The worm attaches to the side of the tube by ____

Answer 43

ventral suckers

Question 44

What are fans? (Chaetopteridae)

Answer 44

Modified parapodia on segments 14 to 16 that pump water through the tube by rhythmical movements.

Question 45

(Chaetopteridae) A pair of ____ on segment 12 secretes a long mucous net that reaches back to a small food cup just in front of the fans.

Answer 45

enlarged parapodia

Question 46

One of two large subgroups within Pleistoannelida that comprises the motile polychaetes.

Answer 46

Errantia

Question 47

Most errant polychaetes are (habitat) ____

Answer 47

Marine

Question 48

Colors of Erantia

Answer 48

They may be brightly colored in reds and greens, iridescent, or dull.

Question 49

Errantia play a significant part in marine food chains because they are _____

Answer 49

eaten by fish, crustaceans, hydroids, and many other predators. 

Question 50

Errantia have many setae, usually arranged in bundles on the ____. 

Answer 50

parapodia

Question 51

A polychaete typically has a ____, which may or may not be retractile and which often bears eyes, tentacles, and sensory palps

Answer 51

prostomium

Question 52

True or False: The peristomium surrounds the mouth and may bear setae, palps, or, in predatory forms, chitinous jaws

Answer 52

True

Question 53

A polychaete’s digestive system consists of a ___, a ___, and a ___.

Answer 53

foregut; midgut; hindgut

Question 54

The foregut of errant polychaetes includes a ___, a ____, and an anterior ____.

Answer 54

stomodeum; pharynx; esophagus

Question 55

In Errantia, The more ____ portions of the midgut secrete digestive enzymes but absorption occurs toward the ____ end. 

Answer 55

anterior; posterior

Question 56

In Errantia, a short ____ connects the midgut to the exterior via the anus, which is on the pygidium.

Answer 56

hindgut

Question 57

True or False: Sense organs are highly developed in polychaetes and include eyes, nuchal organs, and statocysts.

Answer 57

True

Question 58

The highest degree of eye development occurs in the family ____, which has large, image-resolving eyes similar in structure to those of some cephalopod mollusks, with cornea, lens, retina, and retinal pigments.

Answer 58

Alciopidae

Question 59

True or False: Polychaetes have no permanent sex organs, and they usually have separate sexes.

Answer 59

True

Question 60

Errant polychaetes that live in mucus-lined burrows in or near low tide.

Answer 60

Clam worms

Question 61

Clam worms are most active at ____, when they wiggle out of their hiding places and swim or crawl over the sand in search of food

Answer 61

Night

Question 62

Why are Hermodice carunculata called fireworms?

Answer 62

Their hollow, brittle setae contain a poisonous secretion.

Question 63

____ contains many polychaetes and oligochaetes that live in tubes or burrows, including members of the former phyla

Answer 63

Sedentaria

Question 64

Clade ____ contains earthworms and their relatives as well as leeches in class Hirudinida.

Answer 64

Clitellata

Question 65

Earthworms feed mainly on _____

Answer 65

decaying organic matter, bits of leaves and vegetation, refuse, and animal matter.

Question 66

Earthworms feed mainly on ____

Answer 66

decaying organic matter, bits of leaves and vegetation, refuse, and animal matter.

Question 67

Annelids have a double transport system: ____ and a ____ circulatory system.

Answer 67

coelomic fluid; closed

Question 68

The nervous system in earthworms consists of a ____ and peripheral nerves.

Answer 68

central system; peripheral nerves.

Question 69

True or False: Earthworms react negatively to mechanical stimuli when such stimuli are moderate and positively to a strong stimulus

Answer 69

False; positively to mechanical and negatively to strong

Question 70

True or False: Earthworms do not avoid light

Answer 70

False; they avoid unless it is very weak

Question 71

____ aid earthworms in the choice of food.

Answer 71

Chemical responses

Question 72

True or False: Earthworms are monoecious

Answer 72

True

Question 73

Freshwater oligochaetes usually are ____ and have more conspicuous setae than earthworms.

Answer 73

smaller

Question 74

True leeches have ___ segments, entirely lack setae, and possess anterior and posterior suckers.

Answer 74

34

Question 75

Members of order Acanthobdellida have ___ segments, bear setae on the first ___ segments, and have a ___ sucker.

Answer 75

27; 5; posterior

Question 76

Members of order Branchiobdellida have __ or __ segments, no setae, and an ___ sucker

Answer 76

14; 15; anterior

Question 77

Leeches occur predominantly in ___ habitats

Answer 77

Freshwater

Question 78

Leeches are usually flattened ____

Answer 78

dorsoventrally

Question 79

Sa leeches, the ____ secretes a cocoon for reception of eggs.

Answer 79

clitellum

Question 80

True or False: Unlike other annelids, leeches have a fixed number of segments

Answer 80

True

Question 81

Leeches lack distinct ____ compartments

Answer 81

coelomic

Question 82

Explain gas exchange in leeches

Answer 82

Occurs only through the skin except in some fish leeches, which have gills.

Question 83

Leeches have two “brains”: one is ___ and composed of ___ pairs of fused ganglia; the other is ____ and composed of ___ pairs of fused ganglia

Answer 83

anterior - six; posterior - seven

Question 84

Leeches are ____ but cross-fertilize during copulation

Answer 84

hermaphroditic

Question 85

Fluid pressure in fluid-filled coelomic compartments is used to create a _____, which in turn permits precise movements such as burrowing and swimming.

Answer 85

hydrostatic skeleton