Deck 17: Annelids and Allied Taxa

Question 1

Polychaetes crawl by means of leg-like ________ which also serve in respiration.

A)aortic arches
B)metanephridia
C)clitella
D)palps
E)parapodia

Answer 1

E

Question 2

Giant axons are utilized in the earthworm for

A)coordinating mating.
B)rapid escape movements.
C)preventing drowning.
D)coordinating digestion.
E)improving the visual sensory system.

Answer 2

B

Question 3

In contrast to roundworms,how do segmented worms elongate or stretch lengthwise?

A)Contracting the longitudinal muscles
B)Contracting circular muscles
C)Forcibly expanding the circular muscles
D)Forcibly expanding longitudinal muscles
E)Snapping back to original shape of the hard cuticle

Answer 3

B

Question 4

The calciferous glands in the earthworm

A)produce enzymes for digestion.
B)are the respiratory organs.
C)secrete calcium ions into the gut.
D)provide nutritive fluid for the sperm.
E)store glycogen and transport it to body tissues.

Question 5

The high degree of development of eyes in the family Alciopidae is related to

A)their need to detect predators in adjacent soil.
B)the large size of their prey.
C)the active movement of their prey.
D)the different wavelengths of light,the absorption of which varies according to the depth of the water.
E)their tube-dwelling existence.

Question 6

Considering the age of the various segments of an annelid such as an earthworm,

A)they are born with all segments present and these merely grow in size;this allows segment count to be a major feature in their identification.
B)new segments are added just behind the prostomium,so the oldest segments are at the posterior end.
C)new segments are added just in front of the pygidium,so the oldest segments are at the anterior end.
D)each segment doubles several times in life so all of the segments are half or one-fourth "new" at any one time.
E)segments grow and duplicate in a haphazard fashion preventing their use in identification.

Question 7

Each internal compartment of an annelid is lined with

A)amebocytes that serve to distribute food and remove wastes.
B)nephridiocytes that keep the coelomic fluid in circulation.
C)cuticle secreted by the epithelium.
D)peritoneum,a layer of ectodermal epithelium.
E)peritoneum,a layer of mesodermal epithelium.

Question 8

Chloragogen cells

A)float free to distribute materials to body tissues.
B)accumulate around wounds and regenerating areas where they break down and release their contents into the coelom.
C)function in excretion.
D)have a function similar to those of liver cells.
E)All of the choices are correct.

Question 9

The typical nervous system of a polychaete consists of

A)cerebral ganglia and a double ventral nerve cord with ganglia in each segment.
B)a ladder-like pattern similar to that of a flatworm.
C)a distributed nerve net without a central nervous system.
D)a brain,a dorsal nerve cord,and major ganglia in the segments with the clitellum.
E)major digestive ganglia that extend to all parts of the polychaete.

Question 10

The Formation of Vegetable Mould Through the Action of Worms is the title of a classic study by Charles Darwin.What is the true role of earthworms in soil formation?

A)Earthworms can ingest their weight in soil every day,enriching it with organic material.
B)Earthworms consume valuable air that is needed by plant roots.
C)Earthworms are harmful to plant and spread plants root diseases.
D)All of the choices are correct.
E)None of the choices is correct.

Question 11

The body wall of an annelid consists of

A)an epidermis and longitudinal muscles only,as is the case with nematodes.
B)a non-living cuticle,and inner circular muscles to squeeze the cuticle.
C)an epithelium that secretes cuticle,and layers of both longitudinal and circular muscles.
D)a bare epidermis with inner circular muscles and outer longitudinal muscles.
E)a soft exoskeleton to hold up in the absence of inner fluids,with outer circular muscles and inner longitudinal muscles.

Question 12

Polychaetes differ from other annelids because polychaetes

A)lack any head or specialized sense organs.
B)have paired parapodia on most segments.
C)have a clitellum used for reproductive purposes.
D)lack setae.
E)All of the choices are correct.

Question 13

The blood of an earthworm contains

A)hemoglobin packaged in red blood cells similar to the blood of mammals.
B)only hemolymph with no respiratory pigments,similar to the hemolymph of insects.
C)white blood cells that assume the job of carrying respiratory gases.
D)chloragogen as a substitute respiratory pigment.
E)colorless ameboid cells and hemoglobin molecules dissolved in the fluid.

Question 14

You experiment with a live earthworm and notice the following results: - With an intact earthworm,when you "poke" a segment,it contracts.- When you cut off the first segments containing the brain,the remaining worm still crawls.- When you cut the nerve in each septal wall,contractions continue.- If you cut the body wall,leaving the nerve cord intact,crawling still continues.- When you cut both the body wall nerve and the nerve cord,there are no longer any coordinated contractions.What is a reasonable conclusion?

A)An earthworm's brain controls crawling.
B)The ventral nerve cord controls all contractions.
C)Mechanical stimulation of each segment triggers contractions.
D)Earthworms use ventral nerve cord to coordinate contractions along the length of the worm and mechanical stimulation of each segment to triggers segmental responses during crawling.
E)None of the choices is correct.

Question 15

A robin has difficulty pulling an earthworm from its earthen burrow because of small chitinous bristles called

A)parapodia.
B)segments.
C)annuli.
D)metanephridia.
E)setae.

Question 16

Many polychaetes are euryhaline meaning that they

A)can tolerate a wide range of salinity.
B)must live in marine conditions.
C)possess both male and female reproductive organs.
D)always live in tubes.
E)lack any circulatory system.

Question 17

The circulatory system of earthworms is

A)closed with hearts pumping blood to the anterior arteries and veins returning from the posterior.
B)open with blood "washing" through the coelomic cavity.
C)half closed with hearts pushing blood toward the head but washing posteriorly through an open cavity.
D)closed with dorsal and ventral blood vessels joined by five paired "hearts" forcing circulation flow dorsal-ventrally.
E)absent and they rely solely on diffusion to absorb gases through the epidermis.

Question 18

In the earthworm,the typhlosole

A)is the organ of locomotion.
B)increases the absorptive area of the gut.
C)grinds the food.
D)produces secretions during mating.
E)coordinates the contractions of the digestive system.

Question 19

Select the list of characteristics typical of annelids.

A)Segmentation,open circulation,and metanephridia
B)Segmentation,a closed circulatory system,and metanephridia
C)An exoskeleton,metanephridia,and a pseudocoelom
D)An exoskeleton,Malpighian tubules,and a pseudocoelom
E)Metanephridia,a true coelom,and open circulation

Question 20

The polychaetes

A)belong to the smallest and most evolutionarily derived group of annelids.
B)are mostly freshwater inhabitants.
C)are mostly terrestrial,living in moist soil.
D)consist of active predators and sedentary particle feeders.
E)cannot tolerate brackish or marine salinity.

Question 21

The feathery arms of fanworms that trap food particles are called ___________ _____________.

Question 22

Darwin observed earthworm behavior where a worm would seize a leaf fragment by its narrow end in order to pull the leaf into its burrow.This behavior is

A)evidence of high level reasoning.
B)mainly a product of trial and error.
C)genetic or innate.
D)proof of an extensive ability to learn.
E)now known to be totally random.

Question 23

Conventional external fertilization involves both males and females extruding gametes into the environment where they fertilize separate from the parents;internal fertilization involves sperm being transferred to the female with fertilization inside the female.A leech utilizes

A)conventional external fertilization.
B)standard internal fertilization.
C)internal fertilization but by hypodermic impregnation that penetrates the integument.
D)no transfer of sperm at all but regenerates asexually.
E)None of the choices is correct.

Question 24

____________ organs are ciliated sensory pits or slits that appear to be chemoreceptive for food gathering.

Question 25

Reproduction in the earthworm involves

A)asexual budding.
B)self-fertilization.
C)cross-fertilization between two dioecious organisms.
D)cross-fertilization between two hermaphroditic organisms.
E)reproduction by "stem mothers."

Question 26

A unique feature of the leech nervous system is that

A)leeches have good eyesight.
B)leeches have two "brains";one anterior and one posterior.
C)they can join their nervous system with the nerves in the host tissue.
D)it only has giant axons that provide fast responses.
E)the nerve ladder and ganglia are all dorsal.

Question 27

The Sipunculans live in burrows and feed on sediment deposits using

A)a non-retractile spoon-shaped proboscis.
B)a chitinous cuticle.
C)a segmented opisthosoma.
D)a retractile introvert with ciliated tentacles.
E)None of the choices is correct.

Question 28

The circulatory system in the earthworm

A)is absent since all respiration is across the epidermis.
B)is an open system where hemolymph washes through body sinuses.
C)has a dorsal vessel as the main pumping organ.
D)has no pumping structure but depends on the action of body muscles to move the blood.
E)has five pumps that circulate blood first to the gills and then to the rest of the body.

Question 29

Compared to earthworms,freshwater oligochaetes

A)have more conspicuous setae.
B)have better-developed sense organs.
C)are more mobile.
D)All of the choices are correct.
E)None of the choices is correct.

Question 30

The remaining valid use of "medicinal leeches" is to

A)apply them to severely-bruised tissue to relieve blood congestion and allow damaged vessels to grow back.
B)use them to clean out dead tissue from a wound.
C)use them to restore the balance of body fluids or humors.
D)apply them to increase circulation or blood flow to a region.
E)All of the choices are correct.

Question 31

Gas exchange in the earthworm occurs through the

A)gills.
B)metanephridia.
C)skin.
D)setae.
E)typhlosole.

Question 32

Paired appendages used for locomotion in polychaetes are called ___________________.

Question 33

The anterior-most and posterior-most portions of the annelid body are the ______________________ and pygidium,respectively.

Question 34

A biologically plausible reason that burrowing earthworms have solid segmental walls but nonburrowing and parasitic annelids often have partial septa is

A)the segmentation was selected to enable better expansion during burrowing.Parasitic annelids do not burrow and the loss of the ability to expand segments was not disadvantageous during their evolution.
B)the nonburrowing worms were primitive and had not yet developed full walls.
C)nonburrowing worms are halfway between roundworms and fully-segmented earthworms.
D)that it permits fragmentation and regeneration of body parts,which earthworms need because they are in a dangerous environment,but internal parasites do not need this.
E)None of the choices is correct.

Question 35

The cocoon in the earthworm is produced by the

A)clitellum.
B)prostomium.
C)calciferous glands.
D)chloragogen cells.
E)typhlosole.

Question 36

A leech

A)has a clitellum only during the breeding season.
B)has a fixed number of segments.
C)has both anterior and posterior suckers.
D)has a coelomic cavity filled with connective tissue.
E)All of the choices are correct.

Question 37

Members of the Phylum Sipuncula are also known as the

A)bryzoans.
B)beard worms.
C)tongue worms.
D)peanut worms.
E)None of the choices is correct.

Question 38

When earthworms copulate,each stores the other's sperm in chambers called a/an

A)clitellum.
B)egg capsule.
C)nephridiopore.
D)seminal receptacle.
E)seminal vesicle.

Question 39

Oligochaetes are primarily

A)marine.
B)aquatic.
C)terrestrial.
D)parasitic.
E)micropredators.

Question 40

Leeches

A)are mostly found in fresh water.
B)are largely "micropredators" but sometimes parasites.
C)may be carnivores on small invertebrates.
D)are more abundant in the tropics.
E)All of the choices are correct.

Question 41

Why do zoologists not have a well-accepted theory for the origin of segmentation?

Question 42

Discuss the importance of a trochophore larva in both the Annelida and the Mollusca.

Question 43

Why does the wound from the bite of a leech bleed profusely?

Question 44

The Branchiobdellida,is a group of small annelids that contains parasites or commensals of crayfish.They show similarities to both oligochaetes and leeches in that they bear a head sucker.In your analysis,is the evolution of a head sucker a derived trait in an oligochaete lineage or would the loss of posterior sucker place them in the Hirudinea?

Question 45

Speculate why polychaetes are overwhelmingly marine organisms.

Question 46

In the earthworm,food is drawn into the mouth by the pumping action of the _____________.

Question 47

Older taxonomic treatments represent the Annelida as consisting of three classes: Polychaeta,Oligochaeta,and Hirudinea.Compare and contrast that representation to what we know about phylogenetic relationships within the phylum today.

Question 48

The spaces in the coelom of leeches are called the _______________.

Question 49

The temporary food storage organ in the earthworm is the _________________.

Question 50

When earthworms mate,the _______________ secretes mucus to hold them together.

Question 51

The most recent molecular evidence suggests that the Annelida and Mollusca are more closely related to each other (in the clade Lophotrochozoa)rather than either phylum is to the Arthropoda (clade Ecdysozoa).Do you think 1)it matters that this distinction is made,and 2)should the use of molecular evidence by itself be the sole means of distinguishing the affinities of these groups? Support your argument.

Question 52

Of what evolutionary significance is the "hydrostatic skeleton"?

Question 53

In leeches,a cocoon into which fertilized eggs will be deposited is secreted by the __________.

Question 54

The Hirudinida are unique in that they have both an anterior and a posterior ___________.

Question 55

________________ cells surround the intestine in the earthworm and function in excretion and in synthesizing glycogen and fats.

Question 56

Discuss why segmentation is such an important innovation in the Annelida.

Question 57

Earthworms are hermaphroditic.Is this an evolutionary relic where they have been unable to evolve separate sexes,or is this an advantage for an organism with their life style? Explain your answer.rev: 10_28_2014_QC_57578