Deck 33: Protostome Animals

Question 1

The common ancestor of the protostomes had a coelom.What does this suggest?

A)All lophotrochozoans have a coelom.
B)There are no pseudocoelomates within the protostomes.
C)There are no acoelomates within the protostomes.
D)The body cavity evolved before the lophophore.

Answer 1

D

Question 2

Which mollusk group can be described as having several calcium carbonate plates along their dorsal side?

A)bivalves
B)gastropods
C)chitons
D)cephalopods

Answer 2

C

Question 3

The body cavity type for arthropods and mollusk can best be described as _____.

A)coelom
B)pseudocoelom
C)reduced coelom
D)no coelom

Answer 3

C

Question 4

When considering the wormlike phyla within the protostomes,which feature is most useful in distinguishing groups?

A)the type of body cavity
B)the presence or absence of a hemocoel
C)feeding structures or mouthparts
D)hydrostatic skeleton

Question 5

If you wanted to identify an unfamiliar protostome with a limbless,wormlike body,which characteristic would not be helpful in differentiating one species from another?

A)what kind of mouthparts the organism had
B)whether the organism metamorphosed into a different form
C)whether the organism moved using a hydrostatic skeleton
D)whether the organism's body was divided into segments

Question 6

What do all the Lophotrochozoa phyla discussed in the text have in common?

A)They feed using lophophores,specialized ciliated structures.
B)They have trochophore larvae,which swim with the aid of a ring of cilia.
C)They have members that reproduce sexually and members that reproduce asexually.
D)They grow by shedding an exoskeleton or cuticle.

Question 7

Which of the following do Nematoda and Arthropoda have in common?

A)The initial pore formed in the gastrula stage becomes the anus.
B)They are suspension feeders.
C)They grow by shedding their outer covering.
D)They are lophotrochozoans.
E)They have the same kind of unique,ciliated larvae.

Question 8

The presence of a lophophore in a newly discovered species would suggest which of the following?

A)This species has an exoskeleton.
B)This species grows by shedding its external covering.
C)This species is more closely related to an arthropod than a mollusk.
D)This species is motile.
E)This species is a suspension feeder.

Question 9

You find an animal and believe it is a new species of Nemertean.Which line of evidence would support your hypothesis?

A)It grows by shedding its soft outer cuticle.
B)Its body form is that of a worm.
C)It has a proboscis.
D)It burrows into the sand and waits for prey.
E)It feeds by extending its proboscis,grasping its prey,and pulling the food into its mouth.

Question 10

Which of these mollusk features substitutes for the coelom by providing a space for organ development and circulation of bodily fluids?

A)visceral mass
B)foot
C)mantle
D)mantle cavity

Question 11

Here is a statement from the text:
"The ability to live in terrestrial environments evolved independently in arthropods (at least twice),mollusks,roundworms,and annelids." What logical conclusion would you make from this statement?

A)All these groups have a coelom.
B)The common ancestor of all these groups was probably aquatic.
C)All these groups have the same type of body plan.
D)All these groups lost their coelom after moving to land.

Question 12

Among protostomes,which morphological trait has shown the most variation?

A)type of symmetry (bilateral vs.radial vs.none)
B)type of body cavity (coelom vs.pseudocoelom vs.acoelom)
C)number of embryonic tissue types (diploblasty vs.triploblasty)
D)direction of gastrulation (protostome vs.deuterostome)

Question 13

Which one of these mollusk groups can be classified as suspension feeders?

A)bivalves
B)gastropods
C)chitons
D)cephalopods

Question 14

The protostome developmental sequence arose just once in evolutionary history,resulting in two main subgroups Lophotrochozoa and Ecdysozoa.What does this finding suggest?

A)These two subgroups have a common ancestor that was a deuterostome.
B)The protostomes are a polyphyletic group.
C)Division of these two groups occurred after the protostome developmental sequence appeared.
D)The lophotrochozoans are monophyletic.

Question 15

You find what you believe is a new species of animal.Which of the following characteristics would enable you to argue that it is more closely related to a flatworm than it is to a roundworm?

A)It has a cuticle that it sheds in order to grow.
B)It is a suspension feeder.
C)Its larvae have cilia that they use for feeding and locomotion.
D)It is shaped like a worm.
E)It has a well-developed coelom.

Question 16

Which of the following attributes is true for both arthropod exoskeletons and mollusk shells?

A)They completely replace the hydrostatic skeleton.
B)They are secreted by the mantle.
C)They help retain moisture in terrestrial habitats.
D)They are comprised of the polysaccharide chitin.

Question 17

The major evolutionary split of protostome animals was based on _____.

A)nature of the body cavity
B)presence or degree of segmentation
C)number of germ layers present in embryonic development
D)method of feeding
E)way that the organism grows

Question 18

Figure 33.1

Refer to Figure 33.1.Suppose new molecular analyses indicated that the phylum Annelida had diverged from the arthropod lineage after Onychophora and Tardigrada.What would this imply about protostome evolution?

A)Segmentation evolved only once within protostomes.
B)The annelid lineage gained and then lost the ability to molt.
C)The annelid lineage gained and then lost jointed limbs.
D)Segmentation evolved only once within protostomes;the annelid lineage gained and then lost the ability to molt.
E)Segmentation evolved only once within protostomes;the annelid lineage gained and then lost jointed limbs.

Question 19

A _____ is comprised of a mouth surrounded by ciliated tentacles.

A)trochophore
B)lophotrochozoan
C)lophophore
D)cuticle
E)ecdysozoan

Question 20

In adult arthropods,the hemocoel performs which of the following functions?

A)provides space for the internal organs to grow and function
B)forms a cavity to protect the visceral mass of organs
C)acts as a hydrostatic skeleton for mobility
D)secretes the exoskeleton

Question 21

Figure 33.2
Use the following information when answering the corresponding question(s).
Many terrestrial arthropods exchange gases with their environments by using tracheae,tubes that lead from openings (called spiracles)in the animal's exoskeleton or cuticle directly to the animal's tissues.Some arthropods can control whether their spiracles are opened or closed;opening the spiracles allows the carbon dioxide produced in the tissues to travel down the tracheae and be released outside the animal.Klok et al.measured the carbon dioxide emitted over time (represented by VCO₂)by several species of centipedes.Figure 33.2 presents graphs of their results for two species,Cormocephalus morsitans and Scutigerina weberi.(C.J.Klok,R.D.Mercer,and S.L.Chown.2002.Discontinuous gas-exchange in centipedes and its convergent evolution in tracheated arthropods.Journal of Experimental Biology 205:1019-29. )

Look at the graph for Scutigerina weberi (note the scale of the y-axis)in Figure 33.2.What is the best interpretation of these results?

A)The centipede had its spiracles open the entire time.
B)The centipede had its spiracles closed the entire time.
C)The centipede had its spiracles open when CO₂ emission peaked and closed when CO₂ emission was low.
D)The centipede had its spiracles closed when CO₂ emission peaked and open when CO₂ emission was low.

Question 22

Figure 33.2
Use the following information when answering the corresponding question(s).
Many terrestrial arthropods exchange gases with their environments by using tracheae,tubes that lead from openings (called spiracles)in the animal's exoskeleton or cuticle directly to the animal's tissues.Some arthropods can control whether their spiracles are opened or closed;opening the spiracles allows the carbon dioxide produced in the tissues to travel down the tracheae and be released outside the animal.Klok et al.measured the carbon dioxide emitted over time (represented by VCO₂)by several species of centipedes.Figure 33.2 presents graphs of their results for two species,Cormocephalus morsitans and Scutigerina weberi.(C.J.Klok,R.D.Mercer,and S.L.Chown.2002.Discontinuous gas-exchange in centipedes and its convergent evolution in tracheated arthropods.Journal of Experimental Biology 205:1019-29. )

Compare the graphs in Figure 33.2 of CO₂ emission for Cormocephalus morsitans and Scutigerina weberi.What hypothesis can you make about each centipede's habitat?

A)C)morsitans lives in a habitat that provides more carbon dioxide than does S.weberi.
B)C)morsitans lives in a habitat with more predators than does S.weberi.
C)C)morsitans lives in a colder habitat than does S.weberi.
D)C)morsitans lives in a drier habitat than does S.weberi.

Question 23

Figure 33.2
Use the following information when answering the corresponding question(s).
Many terrestrial arthropods exchange gases with their environments by using tracheae,tubes that lead from openings (called spiracles)in the animal's exoskeleton or cuticle directly to the animal's tissues.Some arthropods can control whether their spiracles are opened or closed;opening the spiracles allows the carbon dioxide produced in the tissues to travel down the tracheae and be released outside the animal.Klok et al.measured the carbon dioxide emitted over time (represented by VCO₂)by several species of centipedes.Figure 33.2 presents graphs of their results for two species,Cormocephalus morsitans and Scutigerina weberi.(C.J.Klok,R.D.Mercer,and S.L.Chown.2002.Discontinuous gas-exchange in centipedes and its convergent evolution in tracheated arthropods.Journal of Experimental Biology 205:1019-29. )

How would a terrestrial centipede most likely benefit from the ability to close its spiracles?

A)Closing spiracles would allow the centipede to move more quickly.
B)Closing spiracles would allow the centipede to retain more moisture in its tissues.
C)Closing spiracles would allow the centipede to stay warmer.
D)Closing spiracles would allow more oxygen from the environment to reach the centipede's tissues.
E)The centipede would not benefit at all.

Question 24

What would be the best anatomical feature to look for to distinguish a gastropod from a chiton?

A)presence of a muscular foot
B)presence of a rasp-like feeding structure
C)production of eggs
D)number of shell plates

Question 25

Which adaptation is unique to insects among all protostomes?

A)the ability to move via jointed limbs
B)the ability to move by flying
C)the ability to consume terrestrial plants
D)the ability to parasitize other organisms
E)the ability to metamorphose

Question 26

What is not true of all arthropods?

A)They metamorphose during development.
B)They have jointed limbs.
C)They grow by molting.
D)They have segmented bodies.
E)They have an exoskeleton or cuticle.

Question 27

What is the only group of Mollusca that does not have a radula?

A)Bivalves
B)Gastropods
C)Chitons
D)Cephalopods
E)All mollusk have a radula.

Question 28

You find a multi-legged animal in your garden and want to determine if it is a centipede or a millipede.You take the animal to a university where a myriapodologist quickly tells you that you've found a centipede.Which of the following may have allowed her to make this distinction?

A)segmentation
B)poison-filled glands
C)the total number of legs
D)egg-laying
E)molting

Question 29

Which of the following organisms would you expect to have the largest surface-area-to-volume ratio?

A)a rotifer
B)a mollusk
C)an annelid
D)an arthropod
E)a platyhelminth

Question 30

Whiteflies are common pest insects found on cotton,tomato,poinsettia,and many other plants.Nymphs are translucent and mostly sessile,feeding on their host plants' phloem (sap)from the undersides of leaves.They undergo incomplete metamorphosis into winged adults.Because whitefly nymphs cannot escape predation by moving,you hypothesize that their translucent bodies make them hard to spot by predators.How could you directly test this hypothesis?

A)Compare rates of predation on whitefly nymphs on plant leaves of different colors (e.g. ,red vs.green poinsettia leaves).
B)Compare rates of predation on whitefly nymphs coated with a nontoxic dye vs.undyed whitefly nymphs.
C)Compare rates of predation on whitefly nymphs vs.whitefly adults.
D)Compare rates of predation on whitefly nymphs by predators that are translucent vs.predators that are not translucent.
E)Compare rates of predation on whitefly nymphs feeding on poisonous plants vs.those feeding on nonpoisonous plants.

Question 31

Upon close inspection of movement in annelids and nematodes,you would notice an obvious difference.Nematodes tend to wriggle back and forth,while annelids tend to contract along their length as their girth swells and then thin out as they stretch.What anatomical feature explains this type of movement?

A)The annelids possess longitudinal muscle fibers that the nematodes lack.
B)The nematodes lack circular muscle fibers.
C)Nematodes lack a coelom.
D)Annelids have a highly specialized nervous system capable of more complex movements.

Question 32

You find a wormlike animal while scuba diving and want to determine whether it is a nudibranch,a polychaete,or a turbellarian.Which of the following would allow you to definitively classify the organism into one of those categories?

A)bristle-like structures on tiny appendages
B)a coelom
C)the ability to swim
D)bright coloration
E)sexual reproduction

Question 33

What would be the most direct effect of removing or damaging an insect's antennae?

A)It would have trouble hearing.
B)It would have trouble mating.
C)It would have trouble eating.
D)It would have trouble seeing.
E)It would have trouble smelling.

Question 34

Which one of these groups does not molt?

A)Crustaceans
B)Arthropods
C)Mollusks
D)Chelicerata
E)Nematoda

Question 35

Figure 33.2
Use the following information when answering the corresponding question(s).
Many terrestrial arthropods exchange gases with their environments by using tracheae,tubes that lead from openings (called spiracles)in the animal's exoskeleton or cuticle directly to the animal's tissues.Some arthropods can control whether their spiracles are opened or closed;opening the spiracles allows the carbon dioxide produced in the tissues to travel down the tracheae and be released outside the animal.Klok et al.measured the carbon dioxide emitted over time (represented by VCO₂)by several species of centipedes.Figure 33.2 presents graphs of their results for two species,Cormocephalus morsitans and Scutigerina weberi.(C.J.Klok,R.D.Mercer,and S.L.Chown.2002.Discontinuous gas-exchange in centipedes and its convergent evolution in tracheated arthropods.Journal of Experimental Biology 205:1019-29. )

Look at the graph for Cormocephalus morsitans in Figure 33.2.What is the best interpretation of these results?

A)The centipede had its spiracles open the entire time.
B)The centipede had its spiracles closed the entire time.
C)The centipede had its spiracles open when CO₂ emission peaked and closed when CO₂ emission was low.
D)The centipede had its spiracles closed when CO₂ emission peaked and open when CO₂ emission was low.

Question 36

In your laboratory,you examine a vial of freshwater from a local pond.You notice several unfamiliar small (less than one millimeter in length)animals and decide to study them.You observe that the animals have a coelom,eat microscopic food particles,reproduce by parthenogenesis,and offspring do not undergo any larval stages.What else would you expect to observe about this organism?

A)a corona
B)a lophophore
C)a scolex
D)chaetae
E)a mantle

Question 37

On which body segment are arthropod wings attached?

A)head
B)abdomen
C)thorax
D)evenly split between the abdomen and thorax

Question 38

A cephalopod's tentacles are modified from its _____.

A)mantle
B)visceral mass
C)foot
D)shell
E)radula