Deck 16: Ambulacraria: Echinoderms and Hemichordates

Question 1

The echinoderms and hemichordates are

A)asymmetrical.
B)diploblastic.
C)deuterostomes.
D)ecdysozoans.
E)lophotrochozoans.

Answer 1

C

Question 2

In sea stars,contraction of the __________ force water into the tube feet of the water vascular system.

A)ampullae
B)lateral canals
C)Polian vesicles
D)hemal rings
E)Tiedemann's bodies

Answer 2

A

Question 3

Sea daisies have a thin membrane,the __________,that digests and absorbs nutrients.

A)tongue
B)pyloric cecum
C)Aristotle's lantern
D)cardiac stomach
E)velum

Answer 3

E

Question 4

The __________ serves as an inlet into the water vascular system.

A)Tiedemann's body
B)Polian vesicle
C)radial canal
D)madreporite
E)ring canal

Question 5

As deuterostomes,the echinoderms and hemichordates share all of the following developmental characteristics except one.

A)The anus develops from the blastopore.
B)The coelom forms from outpockets of the embryonic gut tract.
C)The cleavage is radial.
D)The cleavage is determinate.
E)The larval forms are bilaterally symmetrical and ciliated.

Question 6

The major secretory and absorptive structures of the sea star digestive system are the

A)cardiac stomachs.
B)rectal ceca.
C)Polian vesicles.
D)pyloric ceca.
E)Tiedemann's bodies.

Question 7

The principal nitrogenous waste of sea stars is

A)urea.
B)uric acid.
C)urine.
D)guanine.
E)ammonia.

Question 8

Regeneration of lost parts of a sea star also serves in

A)feeding.
B)sexual reproduction.
C)asexual reproduction.
D)discouraging predators.
E)removing toxins from the body.

Question 9

__________ function in cleaning the body surface of many echinoderms.

A)Ambulacrae
B)Dermal branchiae
C)The madreporites
D)Pedicellariae
E)Cuverian tubules

Question 10

The __________ are found on the oral surface of the arms of the sea star and house the tube feet.

A)pedicellariae
B)ambulacral grooves
C)Polian vesicles
D)lateral canals
E)Tiedemann's bodies

Question 11

Modern adult echinoderms have a form of symmetry known as

A)asymmetry.
B)pentaradial.
C)triradial.
D)bilateral.
E)trilateral.

Question 12

In sea stars,thin folds of the body wall that function in respiration are called

A)filamentous gills.
B)ctenidia.
C)Polian vesicles.
D)book gills.
E)dermal branchiae.

Question 13

In sea stars,the __________ surface is the upper surface of the animal and contains the madreporite.

A)aboral
B)oral
C)madreporite
D)anal
E)rigid

Question 14

Sea stars typically feed

A)on suspended materials.
B)on kelp.
C)on detritus in the sediments.
D)on bivalves.
E)on small fishes.

Question 15

Members of the echinoderm class __________ are called sea stars.

A)Crinoidea
B)Echinoidea
C)Asteroidea
D)Holothuroidea
E)Ophiuroidea

Question 16

In Asteroidea the ________ system consists of strands of tissue that encircle the mouth near the ring canal and run into each arm near the radial canals.As in other echinoderms,this system probably transports digestive products,hormones,and other substances.

A)hemal
B)secretory
C)skeletal
D)muscular
E)excretory

Question 17

In the sea stars,a(n)__________ groove runs along the underside of each arm.

A)madreporite
B)Polian vesicular
C)stone canal
D)tube feet
E)ambulacral

Question 18

Embryologically,the echinoderm water vascular system originates as modification of the

A)pyloric cecae.
B)dermal branchiae.
C)coelom.
D)Tiedemann's bodies.
E)closed circulatory system.

Question 19

When feeding on a bivalve,a sea star everts the _______ from its body.

A)gizzard
B)crop
C)oral (cardiac) stomach
D)pylorus
E)rectal cecum

Question 20

The name Echinodermata translates as

A)spiny skin.
B)spiny skeleton.
C)spiny gut.
D)smooth skin.
E)smooth skeleton.

Question 21

Unlike sea stars,in ophiuroids,the tube feet are extended by

A)contraction of muscles at their bases.
B)ampullae forcing water into the feet.
C)hydrostatic pressure.
D)contraction of their suction disks.
E)contraction of lateral canals.

Question 22

The characteristic larval stage of brittle stars is the

A)dipleurula.
B)brachiolaria.
C)bipinnaria.
D)ophiopluteus.
E)echinopluteus.

Question 23

Echinoderms from this class have been over harvested around the Galàpagos islands,as they have become increasingly popular for both culinary and medicinal uses.

A)Holothuroidea
B)Asteroidea
C)Ophiuroidea
D)Echinoidea
E)Crinoidea

Question 24

The characteristic larva of the echinoids is the

A)dipleura.
B)brachiolaria.
C)auricularia.
D)bipinnaria.
E)pluteus

Question 25

The echinoderms that most closely resemble fossil forms are the

A)crinoids.
B)ophiuroids.
C)holothuroids.
D)asteroids.
E)echinoids.

Question 26

Many echinoderms from this class produce toxins in their body walls that discourage predators.

A)Holothuroidea
B)Asteroidea
C)Ophiuroidea
D)Echinoidea
E)Crinoidea

Question 27

Sea lilies and feather stars belong to the echinoderm class

A)Holothuroidea.
B)Asteroidea.
C)Ophiuroidea.
D)Concentricycloidea.
E)Crinoidea.

Question 28

Basket stars and brittle stars belong to the echinoderm class

A)Asteroidea.
B)Echinoidea.
C)Crinoidea.
D)Holothuroidea.
E)Ophiuroidea.

Question 29

Sea cucumbers respire using

A)large feathery oral tentacles.
B)oral gills.
C)the respiratory tree.
D)the body wall.
E)Cuverian tubules.

Question 30

The skeleton of sea urchins consists of ten sets of closely fitting plates and is called a(n)

A)test.
B)exoskeleton.
C)cuticle.
D)tunic.
E)spine.

Question 31

Which of the following echinoderms may contain venom dangerous to humans?

A)sea stars
B)sea lilies
C)feather stars
D)brittle stars
E)sea urchins

Question 32

The madreporite in sea cucumbers is

A)absent.
B)internal.
C)external.
D)on the Polian vesicles.
E)near the anus.

Question 33

If a brittle star is grasped by an arm,certain muscles may contract to serve and cast off the arm in a process called

A)asexual reproduction.
B)rejection.
C)autotomy.
D)regeneration.
E)escapism.

Question 34

The function of Aristotle's lantern is

A)protection.
B)digestion.
C)chewing.
D)locomotion.
E)regeneration.

Question 35

Of the following structures found in sea stars,which one is also present in brittle stars?

A)pedicellariae
B)tube feet
C)dermal branchiae
D)aboral madreporite
E)ampullae

Question 36

Some sea cucumbers have special tubules of the respiratory tree that contains sticky secretions and toxins and can be everted through the anus; these are called __________ tubules.

A)Tiedemann's
B)Polian
C)holothurion
D)Cuverian
E)malpighian

Question 37

Attached crinoids are called

A)sea daisies.
B)sea lilies.
C)sea urchins.
D)basket stars.
E)feather stars.

Question 38

Sea cucumbers belong to the echinoderm class

A)Holothuroidea.
B)Crinoidea.
C)Asteroidea.
D)Ophiuroidea.
E)Concentricycloidea.

Question 39

Sea urchins and sand dollars belong to the echinoderm class

A)Crinoidea.
B)Asteroidea.
C)Ophiuroidea.
D)Holothuroidea.
E)Echinoidea.

Question 40

The primary circulatory medium in echinoids is

A)blood.
B)hemal fluid.
C)plasma.
D)coelomic fluid.
E)pyloric cecae.

Question 41

The nervous system of enteropneusts is __________ in origin.

A)enterocoelous
B)ectodermal
C)mesodermal
D)endodermal
E)schizocoelous

Question 42

The common name acorn worm is derived from the appearance of the __________ of these worms.

A)collar
B)proboscis
C)hepatic cecum
D)trunk
E)tunic

Question 43

The circulatory system of enteropneusts sends blood anteriorly into a series of sinuses called the __________,that may filter excretory wastes.

A)nephridium
B)flame bulb
C)renette
D)glomerulus
E)renal corpuscle

Question 44

The ciliated larva of an acorn worm is called the

A)brachiolaria.
B)bipinnaria.
C)tornaria.
D)trochophore.
E)pluteus.

Question 45

The water vascular system of echinoderms carries out many functions that are distributed through multiple systems in other animals.Which of the statements below are valid comparisons between the functions of the water vascular system and similar functions in arthropods? Check all that apply.

A) Gas exchange in echinoderms often occurs via diffusion of gases across tube feet.In arthropods there are tracheal systems or gills that provide for gas exchange.
B) The water vascular system is often a means of attachment and locomotion via tube feet of echinoderms.In arthropods,muscles interact with the jointed exoskeleton to produce movement.
C) The water vascular system of echinoderms provides for the release of gametes for external fertilization.Arthropods have oviducts and sperm ducts for the release of gametes to the environment.
D) The water vascular system has sensory function in virtually all echinoderms.In some echinoderms,it also may be involved with suspension feeding.In arthropods,the exoskeleton is modified for sensory perception and feeding usually involves specialized mouthparts and other modified appendages.

Question 46

Ambulacrarians and chordates are united into the clade Deuterostomia.In addition to sharing deuterostome characters like radial cleavage and an anus that forms in the region of the embryonic blastopore,the validity of the clade is supported by a wealth of molecular evidence.Another synapomorphy was once considered to be uniquely chordate,but now it is thought to have evolved very early in the deuterostome lineage and then lost in the echinoderm branch.This character is

A)a dorsal tubular nervous system.
B)larvae with ciliary bands.
C)a buccal diverticulum.
D)pharyngeal slits.

Question 47

Echinoderms and hemichordates are more closely related to mammals than to crabs and shrimp.Indicate below if this statement is True or False,followed by the correct reasoning for that answer.Check all of the answer choices that apply.

A) True.Echinoderms,hemichordates,and mammals are all deuterostomes.
B)False.Crabs,shrimp,echinoderms and hemichordates are all invertebrates and chordates are vertebrates.
C)True.Echinoderms,hemichordates,and mammals all share developmental characteristics including determinant cleavage and a mouth that forms in the region of the blastopore.
D) True.This relationship is supported by molecular evidence.

Question 48

Enteropneusta are wormlike as adults and pterobranchia live attached to the substrate.Which of the following are similarities that warrant their inclusion in the common phylum Hemichordata? Check all that apply.

A) Ciliated pharyngeal slits
B) Tripartite coelom
C) Dorsal nervous system
D) Similar feeding habits

Question 49

Synchronous spawning by enteropneusts suggests the presence of

A)asexual reproduction.
B)epitoky.
C)parthenogenesis.
D)protandry.
E)pheromones.

Question 50

Nutritionally,pterobranchs are

A)filter feeders.
B)parasitic.
C)mutualistic.
D)commensalists
E)predators.

Question 51

Exchange of respiratory gases in enteropneusts is accomplished at the pharyngeal slits and by

A)diffusion in alveolar lungs.
B)active transport in the tracheal system.
C)diffusion across the body wall.
D)facilitated diffusion in dermal branchiae.
E)facilitated diffusion in book gills.

Question 52

Coiled masses of fecal material called __________ are deposited on the substrate at one of the openings of the burrow of an enteropneust.

A)castings
B)mucus
C)detritus
D)particulate matter
E)pseudofeces

Question 53

Sea daisies were formerly assigned to a class of their own.They have been recently assigned to the echinoderm class

A)Asteroidea.
B)Ophiuroidea.
C)Holothuroidea
D)Crinoidea.
E)Echinoidea.

Question 54

Enteropneusta and Pterobranchia are classes of animals within the phylum Hemichordata.Which of the following characters could be used to distinguish between members of these two classes?

A)Filter feeding vs.deposit feeding
B)Open vs.closed circulatory system
C)Presence or absence of pharyngeal slits
D)Dorsal vs.ventral nervous system

Question 55

Most modern echinoderms assume a mouth-down feeding and locomotion posture.Members of the class Crinoidea are an exception.They are attached,mouth-up,and feed using tube feet to trap food from the water column.Recent molecular analyses show the Crinoidea to be basal to other extant classes.Which of the following help to explain these observations?

A)Feeding and locomotion posture is not a phylogenetically significant character as all fossil echinoderms assumed a mouth-down posture.
B)The mouth-up posture must be an ancestral character.The mouth-down posture evolved secondarily.
C)The molecular analyses must be in error.The mouth-up posture is phylogenetically significant and must have been derived secondarily.
D)There is no reasonable explanation for these observations at this time.

Question 56

Members of the phylum __________ include acorn worms and pterobranchs.

A)Hemichordata
B)Echinodermata
C)Echiura
D)Chordata
E)Pogonophora

Question 57

Which of the following is a characteristic of animals in the phylum Hemichordata?

A)closed circulatory system
B)incomplete digestive tract
C)ciliated pharyngeal slits
D)indeterminate cleavage
E)blastopore develops into the mouth

Question 58

Which is the only class of echinoderms where the oral surface is not oriented to the substrate?

A)Asteroidea.
B)Ophiuroidea.
C)Holothuroidea
D)Crinoidea.
E)Echinoidea.

Question 59

Acorn worms belong to the class

A)Ascidacea.
B)Concentricycloidea.
C)Pterobranchia.
D)Enteropneusta.
E)Thaliacea.

Question 60

The anterior region of the digestive tract of enteropneusts contains the gill slits.This region is called the

A)pharynx.
B)esophagus.
C)buccal cavity.
D)atrium.
E)stomach.

Question 61

Enteropneusta and Pterobranchia are classes of animals within the phylum Hemichordata.All of the following are features relating to reproduction in members of the Hemichordata.Three features listed are either common to members of both classes or occur only in Enteropneusta.Select the one feature that occurs only in Pterobranchia.

A)External fertilization
B)Ciliated tornaria larval stage
C)Asexual budding common
D)Dioecious with gonads in anterior trunk

Question 62

All of the following are true of members of the Pterobranchia except one.

A)They live in secreted tubes.
B)They live mostly deep water in Southern Hemisphere oceans.
C)Their bodies are divided into three regions: proboscis, collar, and trunk.
D)Their excretory products are eliminated via blood sinuses called a glomerulus.