Deck 22: Chaetognaths, Echinoderms, and Hemichordates

Question 1

Pedicellariae are

A) larval sea stars.
B) the mouth-like openings into the center of the bottom of the sea star.
C) structures linking the madreporite and the ring canal.
D) small pincer-like projections clustered on the skin of a sea star which serve to keep it clean of parasites and aquatic growth.
E) soft and delicate projections of the coelomic cavity covered with epidermis.

Answer 1

D

Question 2

The Chaetognaths

A) have radial symmetry.
B) feed on clams.
C) are small ancestors of fish.
D) are mostly pelagic plankton feeders.
E) are solidly advanced deuterostomes.

Answer 2

D

Question 3

Arrow worm anatomy

A) lacks any coelom.
B) lacks a complete digestive tract.
C) has gills.
D) has well-developed circulatory and excretory systems.
E) is unlike any other invertebrate in having a many-layered epidermis.

Answer 3

E

Question 4

Arrow-worms feed

A) on plankton and small fish.
B) by retracting a hood and snapping onto food items.
C) by surfacing at night and drifting transparently among plankton.
D) All of the choices are correct.
E) None of the choices are correct.

Question 5

Within basic research,sea urchins have been a standard research animal in

A) immunology.
B) study of respiratory systems.
C) study of bone.
D) digestive anatomy.
E) molecular embryology.

Question 6

The common name for chaetognaths is

A) arrow worms.
B) acorn worms.
C) spoon worms.
D) lancelets.
E) elvers.

Question 7

Ecologically,sea stars are at what trophic level?

A) Producer
B) Herbivore
C) Top carnivore
D) Omnivore
E) Detritivore

Question 8

The fossil record of echinoderms

A) is sparse with few representatives.
B) shows echinoderms were a fairly modern group to arise.
C) indicates early echinoderms were sessile and pentaradial but had a bilateral ancestor.
D) suggests early echinoderms were free-swimming and bilateral but became sessile and pentaradial in recent times.
E) is a clear and detailed history of complex echinoderm evolution.

Question 9

The function of the papulae in the sea star is

A) Respiration
B) Excretion
C) Reproduction
D) Digestion
E) Defense and protection

Question 10

Treating sea urchin eggs with hypertonic seawater or subjecting them to other stimuli causes them to develop without the presence of sperm,a phenomenon called

A) isogamy
B) polyspermy.
C) artificial insemination.
D) artificial parthenogenesis.
E) fertilization sensitivity.

Question 11

Arrow worm reproduction and development involves

A) separate male and female individuals.
B) a larval stage that lacks sense organs.
C) a coelom but there is no peritoneum lining.
D) spiral and unequal cleavage.
E) a coelom formed from the archenteron extending backward, not from pinched off coelomic sacs.

Question 12

Which of the following are considered "irregular" urchins?

A) Sea urchins that swim
B) Sand dollars and heart urchins
C) Sea cucumbers
D) Crinoids
E) Brittle stars

Question 13

Water enters the water vascular system of a sea star through a porous plate on the aboral surface called the

A) Aristotle's lantern.
B) Pedicellariae.
C) Madreporite or sieve plate.
D) Pedicellariae.
E) Ambulacrum.

Question 14

The orientation of a sea star is

A) a dorsal mouth and a ventral spiny surface facing upward.
B) an oral mouth facing downward and an aboral spiny surface.
C) an anterior mouth and a posterior spiny surface.
D) a dorsal oral mouth and a ventral-aboral spiny surface.
E) a ventral mouth and an anti-ventral spiny surface.

Question 15

Echinoderms are

A) mostly pelagic or free-swimming in open ocean.
B) benthic.
C) parasitic.
D) mostly particle feeders.
E) fish predators.

Question 16

The most active of all echinoderms are the

A) sea urchins.
B) sea stars.
C) sea cucumbers.
D) brittle stars.
E) crinoids.

Question 17

The calcareous plates found underneath the epidermis are called the

A) Ambulacrae.
B) Tiedemann's bodies.
C) Madreporite.
D) Pedicellariae.
E) Ossicles.

Question 18

Unique characteristics of echinoderms include all of the following EXCEPT

A) an endoskeleton of plates or ossicles.
B) marine, freshwater, and terrestrial species.
C) pedicellariae.
D) dermal brachiae.
E) a water vascular system.

Question 19

Tube feet run along the ___________ groove that extends along the oral side from the mouth to the tip of each arm.

A) Ambulacral.
B) Hemal.
C) Radial.
D) Dermal.
E) Lateral.

Question 20

Deuterostome characteristics

A) Mouth develops from or near the blastopore
B) Coelom budded off from the archenteron
C) Radial and regulative cleavage
D) Mesoderm derived from or with the endoderm from enterocoelic pouches

Question 21

The oral tentacles of the sea cucumber are

A) modified tube feet.
B) actually primitive lophophores.
C) elaborated pedicellariae.
D) also part of its respiratory tree.
E) completely new structures evolved in this group.

Question 22

A sea star feeds by absorbing food through the

A) tube feet on the tentacles.
B) dermal calcareous ossicles.
C) stone and ring canals.
D) lower part of stomach which is everted.
E) sieve plate.

Question 23

Structures in each arm of a sea star include the gonads,the system that works the tube feet,and

A) kidneys.
B) hearts of a circulatory system.
C) pyloric ceca that produce digestive fluids for extracellular digestion.
D) the intestine that collects large amounts of wastes to expel through the anus.
E) gills.

Question 24

Brittle stars differ from sea stars by

A) lacking pedicellariae.
B) lacking papulae, intestine, or an anus.
C) having the ambulacral grooves closed and covered with arm ossicles.
D) having tube feet without suckers.
E) all of the choices are correct distinctions.

Question 25

Echinoderm evolution is controversial but most zoologists agree that ___________ are related and form one clade.

A) sea stars and brittle stars.
B) sea stars and sea urchins.
C) sea stars and sea cucumbers.
D) sea urchins and sea cucumbers.
E) crinoids and sea urchins.

Question 26

"Bipinnaria" describes the

A) larval form of many echinoderms.
B) central two-branched reproductive structures of sea stars.
C) hydraulic system that controls the tube feet of sea urchins and sea stars.
D) ability of these animals to grow into either males or females.
E) underlying bilateral symmetry of an adult although it appears to be pentaradial.

Question 27

How do the tube feet of sea stars and sea urchins operate?

A) Sticky threads lead back to the mouth and primitive brain
B) Cilia transport hemolymph from chamber to chamber
C) Actin and myosin in muscles in the five arms or "rays" constrict the tube feet directly when stimulated by nerves from the sea star brain
D) A hydraulic system regulates water pressure in the tube feet
E) Each tube foot is an independent organism and the sea star is a colonial mass

Question 28

The crinoids

A) have the most primitive characters
B) have far fewer living species than are found in the fossil record
C) include the shallow-water feather stars of tropical oceans
D) include sea lilies that resemble a stalked flower
E) all of the choices are correct

Question 29

How much nervous system does an echinoderm have? Sea stars have

A) a complex of nerve ganglia in each ray.
B) a central nervous system including a brain.
C) a simple nerve ring and radial nerves leading to simple sensory cells scattered over the epidermis.
D) no genuine nerve cells are found in echinoderms; they operate completely by a hydraulic system.

Question 30

In echinoderms,the main coelomic compartment is

A) missing.
B) a somatocoel.
C) completely converted into the water-vascular system.
D) the pyloric stomach.
E) restricted to a small space around the gonads.

Question 31

The ossicles are penetrated by a meshwork of spaces filled with fibers and dermal cells; the meshwork is _____________ and is unique to echinoderms.

A) Pyloric ceca
B) Radial canals
C) Polian vesicles
D) Coelomocytes
E) Stereom

Question 32

The five pairs of bursae in brittle stars are used for

A) digestion and excretion.
B) respiration and reproduction.
C) reproduction and digestion.
D) circulation and digestion.
E) circulation and excretion.

Question 33

Sea stars reproduce mostly

A) by budding.
B) only asexually by intentionally breaking off appendages.
C) sexually, usually with separate sexes.
D) sexually, with both sex organs on same organism, similar to earthworms, with cross-fertilization.
E) sexually, with both sex organs on same organism, but by self-fertilization.

Question 34

The complex chewing apparatus found in many sea urchins is the

A) Ampulla.
B) Aristotle's lantern.
C) Hydrocoel.
D) Pedicellariae.
E) Petaloid.

Question 35

Which is NOT a correct association of structure and function in sea star anatomy?

A) Ampullae-end of the tube foot that bears the sucker
B) Polian vesicles-fluid storage
C) Tiedemann's bodies-production of coelomocytes
D) Lateral canals-connects the radial canal to the tube feet and has one-way valves
E) Stone canal-joins the madreporite and ring canal

Question 36

The respiratory tree of a sea cucumber is

A) not present in other echinoderms.
B) branches off the cloaca of the animal.
C) also serving in excretion.
D) not a replacement for gas exchange through the skin and tube feet.
E) All of the choices are correct.

Question 37

If the radial nerve in an arm is cut,the podia in that arm lose coordination; if the circumoral nerve ring is cut,podia in all arms are uncoordinated and movement ceases.This indicates that

A) the hydraulic system is not involved in movement of tube feet.
B) the radial nerve controls the nerve ring.
C) part of the function of tube feet is hydraulic and part is controlled by the nerve stimulation.
D) water pressure in the hydraulic system is directly controlled by the nervous system.
E) the sea star is aware of the extent it is damaged and can change behaviors to compensate.

Question 38

The role of the hemal system is best described as

A) circulatory.
B) excretory.
C) an accessory gland to the reproductive system.
D) a component of the nervous system.
E) still not known for certain.

Question 39

If you went to the ocean and brought back a sea star to keep in a marine aquarium,what would you feed it?

A) Algae
B) Live clams
C) Live fish
D) Water in plankton since they are filter feeders
E) Living coral

Question 40

The echinoids

A) have five long, slender arms.
B) are enclosed in an endoskeletal test or shell.
C) lack tube feet.
D) lack ambulacral areas.
E) are unable to move because of their spines.

Question 41

The pores leading to both the protocoel and paired coelomic cavities of the enteropneust hemichordates allow

A) fertilization of eggs by sperm.
B) exchange of fluids for a low efficiency respiratory system.
C) water to be drawn in to stiffen the chambers to aid in burrowing.
D) excretion of wastes.
E) movement of ions and water to keep an osmotic balance.

Question 42

The excretory system of an enteropneust hemichordate (or acorn worm)consists of

A) a glomerulus or network of blood vessels that surround the sinus and buccal diverticulum.
B) a rich supply of blood vessels in the gill slits.
C) a network of flame cells at the periphery.
D) a simple metanephridium that empties into the cloaca.
E) a network of vessels under the epidermis.

Question 43

During metamorphosis of sea stars,the left side of the larva becomes the oral surface of the adult,and the right side becomes the ___________ surface.

Question 44

The larvae of echinoderms have ______________ symmetry.

Question 45

Hemichordates live

A) in the open ocean with a similar lifestyle to arrow-worms (which is why they are considered related).
B) in kelp beds.
C) in deep oceans, especially the rich and oxygenated Arctic Ocean.
D) on the bottom of shallow oceans, sometimes colonially and in secreted tubes.
E) just around thermal vents.

Question 46

A calcareous sieve leading to the watervascular system is the ________________ or sieve plate.

Question 47

The nervous system of an enteropneust hemichordate (or acorn worm)consists of

A) a small brain and a dorsal ladder network of ganglia for each body segment.
B) a network or plexus that runs underneath the epithelial cells that fuse to become ventral and dorsal neurochords.
C) a small brain and a ventral ladder network of ganglia for each body segment.
D) no brain but an extensive network of ganglia transferring information from sensory organs to the digestive system.
E) no specialized nerves; the epitheliomuscular must respond to stimuli itself in a manner similar to the cnidarians.

Question 48

The designation of hemichordates as primitive chordates in 1885 by Bateson has proved

A) accurate using new molecular data.
B) overenthusiastic since the structure he interpreted as a notochord does not have notochord embryology.
C) completely wrong since new research indicates that all features he interpreted as chordate features are actually other structures.
D) as puzzling today as in 1885.
E) None of the choices are correct.

Question 49

Hemichordates were not recognized until the 1800s because they

A) were considered roundworms.
B) are very rare.
C) are common but only around deep ocean vents.
D) have recently dramatically increased in numbers.
E) had secretive habits and fragile bodies.

Question 50

Hemichordates show relationships to

A) arrow-worms.
B) arthropods and annelids.
C) molluscs and echinoderms.
D) annelids and echinoderms.
E) both the echinoderms and the chordates.

Question 51

Superphylum Ambulacraria contains two deuterostome phyla: Echinodermata and ____________.

Question 52

Chaetognaths are also known as ______ ______.

Question 53

A system of unknown function consisting of tissue strands enclosing unlined channels is the __________ system.

Question 54

On the inner end of each tube foot is a muscular sac called an ______________.

Question 55

The grooves that run along the oral side of the arms of sea stars are called ________________ grooves.

Question 56

The hemichordate "notochord" is

A) the feature proposed by Bateson to include this animal with the chordates.
B) a buccal diverticulum.
C) not homologous with the chordate notochord.
D) All of the choices are correct.
E) None of the choices are correct.

Question 57

Minute,pincer-like ___________________ are found on the surfaces of many sea stars.

Question 58

The larva of an acorn worm is

A) always a juvenile that grows into a bigger adult.
B) a tornaria larvae that resembles an echinoderm bipinnaria larvae.
C) very close in structure to a tunicate larva.
D) nearly identical to a lancelet.
E) None of the choices are correct.

Question 59

The gill slits of enteropneust hemichordates function to

A) house gills.
B) strain food out of the water on the mucus-coated gill slits.
C) allow water to exit after food has been gathered from the inflow.
D) orient the animal in the water.
E) excrete wastes.

Question 60

Small projections between the ossicles of sea stars that function in respiration are the ______________.

Question 61

The madreporite of sea cucumbers is located in the ________________.

Question 62

________________ larvae of nonbrooding echinoids may live a planktonic existence for several months and then metamorphose into young urchins.

Question 63

The mouth of the brittle star is surrounded by five movable plates that serve as ___________.

Question 64

A feature of the earliest echinoderms apparently was development of endoskeletal plates with ______________ structure.

Question 65

These odd little echinoderms were formerly considered a class of their own.They possess tube feet distributed around the periphery of their disclike body and belong to the group ___________.

Question 66

The basic five arms of crinoids are usually branched to form many more,each of which bears barblike ___________.

Question 67

A complex chewing apparatus found in many urchins is the _________ _________.

Question 68

Water for filter feeding in the hemichordates is driven by _________ _________.

Question 69

________________ is the porous plate on the aboral surface where water enters the water vascular system of a sea star.

Question 70

Hemichordates do not have a kidney,but they do have a single _____________.

Question 71

The larva of enteropneust hemichordates is known as a ________________.

Question 72

In brittle stars,water circulates into the _______________ for gaseous exchange.

Question 73

The ancestor of the echinoderms had _____________ symmetry.

Question 74

The Class Enteropneusta are also known as __________________.

Question 75

The water vascular system is derived embryologically from the left _______ ________ ________.

Question 76

Hemichordates are marine animals that were formerly considered a subphylum of ____________.

Question 77

Characteristics of the hemichordates that are shared with the echinoderms and are the basis for the clade Ambulacraria are a diffuse epidermal nervous system and _______ ________.

Question 78

The ___________ ___________ was formerly thought to be a notochord.

Question 79

________________ are pincer-like projections clustered on the skin of a sea star which serve to keep it clean of parasites and aquatic growth.

Question 80

The respiratory tree of sea cucumbers opens into the _________________.