Deck 10: The Smaller Lophotrochozoan Phyla

Question 1

Chemoreceptors that aid in the location of food are especially dense in the __________ of turbellarians.

A)eyespots
B)cerebral ganglia
C)statocysts
D)ocelli
E)auricles

Answer 1

E

Question 2

__________ are rodlike cells of the turbellarian epidermis that swell and form a protective mucous sheath around the body.

A)Endocytes
B)Mucocytes
C)Ectocytes
D)Rhabdites
E)Flame cells

Answer 2

Rhabdites

Question 3

In larger species of turbellarians,the highly branched digestive cavity partially compensates for the

A)lack of anus for egestion.
B)lack of an ingestive organ.
C)absence of a circulatory system.
D)absence of digestive enzymes.
E)inability to digest food extracellularly.

Answer 3

absence of a circulatory system.

Question 4

The simple eyespots seen in most turbellarians are called

A)ocelli.
B)auricles.
C)statocysts.
D)chemoreceptors.
E)plasmids.

Question 5

Which of the functions listed below is NOT a function of the parenchyma of the platyhelminthes?

A)provide skeletal support
B)nutrient storage
C)oxygen storage
D)production of gametes
E)transport of materials

Question 6

A continuous multinucleate layer,formed by cell fusion,is called a/an

A)syncytium.
B)glycocalyx.
C)integument.
D)cuticle.
E)microvillus.

Question 7

Turbellarians glide over substrates using __________ and muscular undulations.

A)cilia
B)parapodia
C)pseudopodia
D)flagella
E)legs

Question 8

The members of the Class Monogenea have tissues that develop from this many germ layers.

A)one
B)two
C)three
D)four
E)five

Question 9

In turbellarian nervous systems,neurons carrying information to the brain are __________ neurons.

A)connector
B)sensory
C)receptor
D)association
E)motor

Question 10

In turbellarians,the nervous tissue is concentrated anteriorly in clusters of neurons called

A)longitudinal masses.
B)ganglia.
C)commissures.
D)nephridiophores.
E)protonephridia.

Question 11

Which of the following is not true of the turbellarian gastrodermis?

A)It secretes digestive enzymes.
B)It absorbs digested food.
C)It contains smooth muscle cells.
D)It consists of a single layer of cells.
E)It is derived embryologically from endoderm.

Question 12

The flame cell system and protonephridia of freshwater turbellarians primarily serve to remove __________ from the body.

A)excess water
B)metabolic waste
C)urea
D)uric acid
E)excess carbohydrates

Question 13

The _______ layer of a fluke is composed of carbohydrates and proteins and helps protect the fluke from the host's enzymes and antibodies.

A)syncytium
B)tegument
C)glycocalyx
D)cuticle
E)plasmodium

Question 14

The free-living flatworms are classified in the class

A)Cestoidea.
B)Turbellaria.
C)Trematoda.
D)Triclada.
E)Acoela.

Question 15

The free-swimming larval stage of some turbellarians is called a/an

A)ephyra.
B)planula.
C)Muller's larva.
D)pilidium.
E)scyphistoma.

Question 16

Among the flatworms,when a digestive tract is present,it has

A)a single opening, the mouth.
B)two openings, mouth and anus.
C)a single opening, the anus.
D)no external opening.
E)a nephridiopore opening.

Question 17

The osmoregulatory organs of turbellarians are called

A)contractile vacuoles.
B)kidneys.
C)metanephridia.
D)mesonephridia.
E)protonephridia.

Question 18

Asexual reproduction by fission in some turbellarians results in a chain of individuals called __________ that later will become independent individuals.

A)larvae
B)zooids
C)buds
D)cocoons
E)bursae

Question 19

Among those turbellarians possessing a digestive cavity,digestion is

A)extracellular only.
B)intracellular only.
C)accomplished before food is ingested.
D)both extracellular and intracellular.
E)accomplished in the pharynx.

Question 20

Most turbellarian species

A)are marine scavengers.
B)are internal parasites with complex life histories.
C)are external parasites of birds and mammals.
D)have complete digestive tracts.
E)are freshwater predators and scavengers.

Question 21

The lidlike hatch on a trematode egg is called the

A)operculum.
B)scolex.
C)opisthaptor.
D)acetabulum.
E)cercaria.

Question 22

The larval stage of the beef tapeworm that encysts in skeletal muscles is called the

A)onchosphere.
B)cysticercus.
C)cercaria.
D)redia.
E)hexacanth.

Question 23

Nemerteans differ from flatworms in that they possess

A)a heart.
B)one way circulation in blood vessels.
C)a complete digestive tract.
D)both male and female reproductive structures in the same individual.
E)a plerocercoid larvae.

Question 24

The proboscis worms belong to the phylum

A)Proboscisoidea.
B)Nematoda.
C)Gnathostomulida.
D)Aspidogastrea.
E)Nemertea.

Question 25

The larval stage of members of class Monogenea is called the

A)redia.
B)oncosphere.
C)sporocyst.
D)oncomiracidium.
E)cercaria.

Question 26

Tapeworms lack

A)reproductive organs.
B)a mouth and digestive tract.
C)excretory structures.
D)holdfast structures.
E)a tegument.

Question 27

The tapeworm strobila is made of many repeated units called

A)proglottids.
B)opercula.
C)scolices.
D)acetabula.
E)miracidia.

Question 28

The epidermis of a fluke has an outer layer called the __________,which forms a syncytium.

A)plasmodium
B)opisthaptor
C)pellicle
D)cuticle
E)tegument

Question 29

The first larval stage in the life history of a digenetic fluke is the

A)redia.
B)miracidium.
C)cercaria.
D)sporocyst.
E)oncomiracidium.

Question 30

The six-hooked (hexacanth)larva that develops from the egg of the beef tapeworm is the

A)onchosphere.
B)miracidium.
C)cysticercus.
D)bladder worm.
E)redia.

Question 31

In the class Trematoda,the phenomena of producing many cercariae is known as

A)polylarvany.
B)multiple host syndrome.
C)polyembryony.
D)multiple embryony.
E)intermediate host reproduction.

Question 32

Blood flukes of the genus __________ are important human parasites.

A)Fasciola
B)Clonorchis
C)Opisthorchis
D)Schistosoma
E)Plasmodium

Question 33

The most highly specialized class of parasites within phylum Platyhelminthes is

A)Aspidogastrea.
B)Trematoda.
C)Platyhelminthes.
D)Monogenea.
E)Cestoidea.

Question 34

Flukes in the subclass Digenea always have two or more

A)mouths.
B)hosts.
C)plant hosts.
D)intermediate hosts.
E)definitive hosts.

Question 35

The encysted larval stage of a digenetic fluke is called the

A)oncomiracidium.
B)sporocyst.
C)metacercaria.
D)redia.
E)oncocercaria.

Question 36

The holdfast structure of a tapeworm is called the

A)strobila.
B)acetabulum.
C)scolex.
D)opisthaptor.
E)proglottid.

Question 37

Scolex,neck,and __________ comprise the three body regions of a tapeworm.

A)abdomen
B)thorax
C)tail
D)strobila
E)trunk

Question 38

The oldest proglottids at the end of a tapeworm are filled with eggs,and are said to be

A)adult.
B)female.
C)pregnant.
D)mature.
E)gravid.

Question 39

The larval stage of the broad fish tapeworm that encysts in muscle is called the

A)coracidium.
B)precercoid.
C)miracidium.
D)plerocercoid.
E)cysticercoid.

Question 40

Most flukes belong to the subclass

A)Aspidogastrea.
B)Monogenea.
C)Eucestoda.
D)Cestodaria.
E)Digenea.

Question 41

Some members of a diverse group of phyla share a common feeding structure and a certain type of larva.These characteristics are synapomorphies that identify these phyla as lophotrochozoans.Other animals are classified as lophotrochozoans but lack these synapomorphies.What explains the fact that animals that have these common characters are grouped with other animals that lack the characters?

A) The characters may have been lost in ancestors of those phyla lacking the characters.
B)Morphological and developmental characters are less important than genetic characters.
C) Animal relationships are "in the eye of the beholder." They are based more on preferences of the investigator than on morphological or genetic evidence.
D) Molecular analyses have shown that lophotrochozoan phyla are related.

Question 42

The proboscis of nemerteans is held within a sheath called the

A)rhynchocoel.
B)gastrovascular cavity.
C)gastrocoel.
D)stylet.
E)anoplan.

Question 43

What is true regarding members of the following phyla: Ectoprocta,Brachiopoda,Annelida,and Mollusca?

A)They possess a lophophore and/or trochophore larvae.
B)They all have a cuticle.
C)They all have a pseudocoelom.
D)They all have a proboscis that is protruded during feeding.

Question 44

Rotifers derive their name from a characteristic ciliated structure called the __________ located on the head.

A)mastax
B)corolla
C)gastrotrich
D)corona
E)proboscis

Question 45

The helmet-shaped,ciliated larva of nemerteans is the

A)onchosphere.
B)Muller.
C)pilidium.
D)miracidium.
E)cercaria.

Question 46

Rotifers exchange respiratory gases

A)across the body surface.
B)through gills.
C)through lungs.
D)with a tracheal system.
E)with dermal branchiae.

Question 47

Acanthocephalans are commonly called

A)roundworms.
B)blood worms.
C)flatworms.
D)probosis worms.
E)spiny-headed worms.

Question 48

Animals in the phyla Cycliophora live exclusively on the mouthparts of

A)pelicans.
B)beetles.
C)lobsters.
D)elephants.
E)snails.

Question 49

The acanthocephalan larval stage that emerges from the egg is called a/an

A)acanthella.
B)cysticercus.
C)acanthor.
D)cystacanth.
E)coelocanth.

Question 50

The wide distribution of rotifers in lakes can be attributed to

A)resting eggs which can withstand adverse conditions.
B)the distribution of eggs by wind.
C)the distribution of eggs by the feet of waterfowl.
D)ability to reproduce parthenogenetically.
E)all of the answers are correct.

Question 51

Some rotifers have a "shell" composed of a thickened cuticle,called the __________,that functions in protection.

A)test
B)lorica
C)ossicles
D)periostracum
E)umbo

Question 52

In the rotifer class __________,amictic eggs develop exclusively by parthenogenesis.

A)Phasmidia
B)Secernentea
C)Seisonidea
D)Monogononta
E)Bdelloidea

Question 53

Covering the tegument of acanthocephalans is a __________,consisting of mucopolysaccharides and glycoproteins.

A)glycocalyx
B)lorica
C)sheath
D)cuticle
E)pellicle

Question 54

Nemerteans differ from flatworms in that they have a complete gut and a

A)reproductive system.
B)circulatory system.
C)well-developed head.
D)well-developed bilateral symmetry.
E)nervous system.

Question 55

Like the tapeworms,acanthocephalans lack

A)a nervous system.
B)a digestive tract.
C)muscles.
D)a reproductive system.
E)a cuticle.

Question 56

In rotifers,two different kinds of eggs are produced.These are __________ and __________ eggs.

A)fertile; infertile
B)mictic; amictic
C)nucleated; unucleated
D)large; small
E)shelled; unshelled

Question 57

Rotifers are

A)primarily marine.
B)relatively large.
C)characterized by a corona and mastax.
D)characterized by populations dominated by males.
E)not eutelic.

Question 58

The rotifer pharynx contains a unique muscular structure called the __________ in which food is ground and macerated.

A)odontophore
B)crop
C)gizzard
D)radula
E)mastax

Question 59

The haploid mictic eggs of some rotifers,if not fertilized,develop parthenogenetically into

A)dormant eggs.
B)males.
C)females.
D)winter eggs.
E)haploid larvae.

Question 60

In the rotifer class Bdelloidea,all females are __________,producing diploid eggs that hatch into diploid females.

A)protandric
B)protogynous
C)parthenogenetic
D)isomictic
E)mictic

Question 61

Which one or more of the following statements accurately reflects our understanding of platyhelminth phylogeny? Select all that apply.

A) The taxonomic status of the entire phylum is in question.Molecular information is often interpreted to support the monophyly of the phylum as we know it,but morphological evidence for that conclusion is tentative at best.
B)The class Trematoda is probably paraphyletic.
C)Monogenea,Cestoidea,and Trematoda almost certainly comprise a monophyletic clade.
D) Turbellaria will probably be abandoned as a valid class designation because molecular studies suggest that it is paraphyletic.

Question 62

Relationships within the Lophotrochoza are tentative.Examine the statements below.Some statements are true and reflect our current state of knowledge,but they would not add any new information to our understanding of lophotrochozoan phylogeny.Others are hypothetical (and probably untrue),but if true they would help clarify lophotrochozoan relationships.Select all statements that would add new information and could change our perception of lophotrochozoan relationships.

A)Annelids,brachiopods and molluscs all have trochophore larval stages.
B)The Turbellaria,Trematoda,Monogenea,and Cestodea all share a common developmental stage.
C)"Platyzoa" is a paraphyletic grouping.
D)New molecular analyses have shown conclusively that Rotifera and Micrognathozoa are closely related.