Deck 31: Protostome Animals

Question 1

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

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

Answer 1

C

Question 2

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

A) foot
B) mantle
C) visceral mass
D) none of the above

Answer 2

C

Question 3

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

A) acts as a hydrostatic skeleton-for mobility-in larval stages
B) provides space for the internal organs to grow and function
C) allows for the circulation of bodily fluids
D) all of the above

Answer 3

D

Question 4

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

A) This species grows by shedding its exoskeleton.
B) This species is a suspension feeder.
C) This species is probably an arthropod.
D) This species grows by shedding its cuticle.

Question 5

As stated in the text, "DNA sequence data indicated that two major subgroups existed within the protostomes." This finding contradicts the long- held hypothesis that the protostomes are a monophyletic group.

Question 6

The major evolutionary split of protostome animals was into

A) diploblasts and triploblasts.
B) lophotrochozoans and ecdysozoans.
C) coelomates and acoelomates.
D) arthropods and molluscs.
E) segmented and nonsegmented animals.

Question 7

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 is shaped like a worm.
B) It is a suspension feeder.
C) It has a cuticle that it sheds to grow.
D) It has a mouth and an anus.
E) It has no coelom.

Question 8

The body cavity type for arthropods and molluscs can best be described as

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

Question 9

Nematodes and arthropods both

A) are suspension feeders.
B) grow by shedding their exoskeleton.
C) develop an anus from the blastopore pore) formed in the gastrula stage.
D) are lophotrochozoans.
E) have ciliated larvae.

Question 10

Figure 31.1
Refer to Figure 31.1. 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) A and B
E) A and C

Question 11

To which of the following terrestrial habitats would it be easiest for an aquatic animal to adapt?

A) rain forest high temperature, high precipitation, high plant biomass)
B) temperate forest moderate temperature, moderate precipitation, moderate plant biomass)
C) subtropical desert high temperature, very low precipitation, low plant biomass)
D) boreal forest low temperature, low precipitation, high plant biomass)
E) tundra very low temperature, very low precipitation, low plant biomass)

Question 12

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 protostome.
B) Division of these two groups occurred after the protostome developmental sequence appeared.
C) The protostomes are a monophyletic group.
D) All of the above apply.

Question 13

Which of the following do Nematoda and Arthropoda not have in common?

A) They are both ecdysozoans.
B) They grow by shedding their outer covering.
C) The initial pore formed in the gastrula stage becomes the mouth.
D) They are suspension feeders.

Question 14

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

A) poisonous fangs
B) egg- laying
C) moulting
D) the total number of legs
E) segmentation

Question 15

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

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

Question 16

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

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

Question 17

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

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

Question 18

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

A) There are no acoelomates within the protostomes.
B) There are no pseudocoelomates within the protostomes.
C) All lophotrochozoans have a coelom.
D) None of the above answers apply.

Question 19

Adaptations to terrestrial environments evolved independently in arthropods, mollusks, nematodes, and annelids. What logical conclusion would you make from this statement?

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

Question 20

Which of the following attributes is not true for both arthropod exoskeletons and mollusc shells?

A) They provide protection from predators.
B) They completely replace the hydrostatic skeleton.
C) They help retain moisture in terrestrial habitats.
D) None of the above answers apply.

Question 21

A cephalopod's tentacles are modified from its

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

Question 22

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

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

Question 23

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's body was divided into segments
D) whether the organism moved using a hydrostatic skeleton

Question 24

Compare the graphs in Figure 31.2 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 with more predators than S. weberi.
B) C. morsitans lives in a habitat that provides more carbon dioxide than S. weberi.
C) C. morsitans lives in a colder habitat than S. weberi.
D) C. morsitans lives in a dryer habitat than S. weberi.

Question 25

Use the following information when answering the corresponding questions).
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 spir 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 31.2 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.) Copyright c) 2002, The Company of Biologists and the Journal of Experimental Biology.
Figure 31.2
How would a terrestrial centipede most likely benefit from the ability to close its spiracles?

A) The centipede would not benefit at all.
B) Closing spiracles would allow the centipede to move more quickly.
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) Closing spiracles would allow the centipede to retain more moisture in its tissues.

Question 26

What is not true of all arthropods?

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

Question 27

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

A) They feed using lophophores, specialized ciliated structures.
B) They have members that reproduce sexually and members that reproduce asexually.
C) They have trochophore larvae, which swim with the aid of a ring of cilia.
D) They expand their bodies continuously during growth.
E) None of the above answers is correct.

Question 28

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

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

Question 29

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

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

Question 30

How could you tell a millipede apart from a centipede?

A) Millipedes have two pairs of legs per body segment, while centipedes have one.
B) Millipedes catch prey using poison, while centipedes are detritivores.
C) Millipedes have 1000 legs each, while centipedes have 100 legs each.
D) Millipedes bear live young, while centipedes lay eggs.
E) None of the above answers is correct.

Question 31

Which one of these groups does not molt?

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

Question 32

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 thins out as they stretch. What anatomical feature explains this type of movement?

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

Question 33

Which adaptation is unique to insects among all protostomes?

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

Question 34

Use the following information when answering the corresponding questions).
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 spir 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 31.2 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.) Copyright c) 2002, The Company of Biologists and the Journal of Experimental Biology.
Figure 31.2
Look at the graph for Cormocephalus morsitans. What is the best interpretation of these results?

A) The centipede had its spiracles closed the entire time.
B) The centipede had its spiracles open 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 35

Use the following information when answering the corresponding questions).
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 spir 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 31.2 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.) Copyright c) 2002, The Company of Biologists and the Journal of Experimental Biology.
Figure 31.2
Look at the graph for Scutigerina weberi note the scale of the y- axis) in Figure 31.2. What is the best interpretation of these results?

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

Question 36

Of what advantage is a large surface- area- to- volume ratio to the Platyhelminthes?

A) It enables the efficient transport of gases and nutrients without specialized structures.
B) It enables their blood vessels to transport oxygen and carbon dioxide more efficiently.
C) It enables them to live in dry habitats.
D) It enables them to survive on very little oxygen.
E) None of the above are advantages.

Question 37

All arthropods
1) undergo complete metamorphosis.
2) have jointed appendages.
3) moult.
4) have segmented bodies.
5) have an exoskeleton or cuticle.

A) 3 and 5
B) 1, 2, and 3
C) 1, 4, and 5
D) 2, 3, 4, and 5
E) 1, 2, and 4

Question 38

On which body segment are arthropod wings attached?

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