Deck 23: Animal Origins and Diversity

Question 1

Clues to the evolutionary relationships of animals can be found in

A) the fossil record.
B) patterns of embryonic development.
C) comparative morphology and physiology.
D) nucleotide sequence patterns.
E) All of the above

Answer 1

E

Question 2

Which feature can be helpful in classifying organisms and is unrelated to the body plan of an organism?

A) The symmetry of the body
B) The structure of the body cavity
C) The segmentation of the body
D) External appendages
E) The larval morphology

Answer 2

E

Question 3

A bilaterally symmetrical animal can be divided into mirror images by

A) any plane through the midline of its body.
B) any plane from its anterior to its posterior end.
C) any plane from its dorsal to its ventral surface.
D) any plane through the midline of its body from its anterior to its posterior end.
E) a single plane through the midline of its body from its dorsal to its ventral surface.

Answer 3

E

Question 4

Which sponge cell type is specialized for creating the currents that draw food particles into the sponge?

A) Spicule
B) Pore cell
C) Osculum
D) Choanocyte
E) Nematocyst

Question 5

Bilaterally symmetrical animals can be divided into two major groups that separated during the Cambrian.These two lineages differ fundamentally in their

A) modes of reproduction.
B) early embryological development.
C) modes of obtaining and storing energy.
D) environmental requirements.
E) metabolism.

Question 6

Which feature is a synapomorphy for the eumetazoans?

A) Two embryonic cell layers
B) Radial symmetry
C) A blastopore that develops into the mouth
D) A blastopore that develops into the anus
E) Distinct organ systems

Question 7

Which feature is a synapomorphy of the animals?

A) Cells that contain chitin
B) Vascular systems
C) Similarities in their Hox genes
D) Bilateral symmetry
E) Spiral cleavage

Question 8

The terms "acoelomate," "pseudocoelomate," and "coelomate" refer to

A) levels of cephalization.
B) the origin of the blastopore.
C) ectoderm,mesoderm,and endoderm,respectively.
D) the body cavity of animals.
E) the vertebrate body plan.

Question 9

Sponges differ from other animals in that they

A) do not form true organs.
B) are sessile.
C) are triploblastic.
D) have trochophore larvae.
E) have pigment.

Question 10

Because all animals must take in nutrients from their environment and digest their food internally,the term applied to the nutritional mode of animals is

A) heterotrophic.
B) photoheterotrophic.
C) photoautotrophic.
D) chemolithotrophic.
E) chemoautotrophic.

Question 11

The most extensive ramification of segmentation in animals,from an evolutionarily perspective,is that it

A) allows organisms to grow much larger than would be possible without segmentation.
B) has allowed organisms to alter their body forms in complex ways.
C) increases the mobility of an organism.
D) reduces the surface area-to-volume ratio.
E) allows body parts to be eaten by predators without killing the organism.

Question 12

On the animal family tree,which group precedes the eumetazoans?

A) Ctenophores
B) Sponges
C) Cnidarians
D) Bilaterians
E) Protostomes

Question 13

Which characteristic helps distinguishes deuterostomes from protostomes?

A) Ectodermal appendages
B) Ability to form a blastopore
C) Embryological origin of the mouth
D) Mesodermal migration
E) Nervous system pigmentation

Question 14

Cephalization is most commonly associated with

A) spherical symmetry.
B) radial symmetry.
C) sessile animals.
D) bilateral symmetry.
E) lophotrochozoan animals.

Question 15

The presence of which feature(s)would prevent an organism from being classified as a sponge?

A) Choanocytes
B) Pores
C) Spicules
D) Mesoderm
E) Eggs

Question 16

Which structure(s)can be involved in generating an animal's movement?

A) Fluid-filled coelom
B) Segmentation
C) Appendages
D) Cilia
E) All of the above

Question 17

What is the main difference between a coelom and a pseudocoelom?

A) A coelom is enclosed by muscle on the outside only;a pseudocoelom is enclosed by muscle on the inside only.
B) A coelom does not have an enclosed body cavity;a pseudocoelom is completely surrounded by muscle.
C) A coelom is enclosed by muscle on the inside only;a pseudocoelom is a solid structure.
D) A coelom is enclosed by muscle on the inside and the outside;a pseudocoelom is surrounded by muscle on the outside of the body cavity.
E) A coelom involves a solid body;a pseudocoelom has muscle on the inside and outside.

Question 18

The ancestor of the animal clade was probably a(n)

A) ctenophore.
B) triploblastic acoelomate with spiral cleavage.
C) ciliated protist.
D) colonial flagellated protist.
E) amoeba.

Question 19

The body cavity of coelomate animals develops within the

A) endoderm.
B) ectoderm.
C) mesoderm.
D) pseudocoel.
E) mesoglea.

Question 20

A pseudocoelomate animal lacks a

A) body cavity.
B) fluid-filled body cavity.
C) fluid-filled body cavity lined on the outside with mesoderm.
D) fluid-filled body cavity lined on the outside and inside with mesoderm.
E) pseudocoel.

Question 21

Which characteristic is not associated with a parasitic lifestyle as seen in tapeworms and flukes?

A) A complex digestive system
B) A flattened body
C) Life cycles with several larval stages
D) Life cycles with multiple hosts
E) A reduced gastrovascular cavity

Question 22

Which feature is an adaptation found in flatworms that is associated with a parasitic lifestyle?

A) Large size
B) A highly branched gastrovascular cavity
C) An oxygen transport system
D) Absorption of nutrients through the body surface
E) A mouth with teeth for latching on to its host

Question 23

You discover a new organism with the following characteristics: a wormlike body with a fluid-filled cavity,a feeding organ that looks like a proboscis,and a complete digestive tract.The organism is most likely a(n)

A) annelid.
B) flatworm.
C) nematode.
D) ribbon worm.
E) horsehair worm.

Question 24

Wormlike organisms are very common,but some phyla,such as _______,contain only other kinds of body plans.

A) nematodes
B) nemerteans
C) annelids
D) polychaetes
E) bryozoans

Question 25

The type of symmetry possessed by the cnidarians is known as _______ symmetry.

A) asymmetrical
B) radial
C) spherical
D) bilateral
E) axial

Question 26

Which statement about bryozoans is true?

A) They are noncolonial.
B) They are wormlike in structure.
C) They are mainly marine.
D) They have lost the trochophore.
E) Individual colony members fuse to produce a large,common lophophore.

Question 27

Which organisms are members of the lophotrochozoan lineage?

A) Sponges
B) Vertebrates
C) Cnidarians
D) Insects
E) Mollusks

Question 28

Which feature is not associated with the rotifers?

A) A pseudocoelom
B) A complete gut
C) Conspicuous feeding organs
D) Radial symmetry
E) Movement by beating cilia

Question 29

Which trait unites the deuterostomes but not the protostomes?

A) Dorsal nervous system
B) Anterior brain
C) Bilaterally symmetrical body plan
D) Development of a mouth from a blastopore (in many species)
E) Radial symmetry

Question 30

Which feature is not associated with the annelids?

A) Trichinosis
B) Closed circulatory system
C) Segmentation
D) Coelom
E) Hydrostatic skeleton

Question 31

Which group includes the fewest species?

A) Mollusks
B) Bryozoans
C) Arthropods
D) Nematodes
E) Lophotrochozoans

Question 32

The cnidarians are considered to be the sister group to which taxon?

A) Ctenophorans
B) Placozoans
C) Bilaterians
D) Sponges
E) Eumetazoans

Question 33

Many lineages of lophotrochozoans have a free-living larva known as a

A) polyp.
B) planula.
C) trochophore.
D) nauplius.
E) choanocyte

Question 34

Which statement about nematocysts is true?

A) They are excretory organs in platyhelminthes.
B) They are reproductive cells in cnidarians.
C) They are ciliated cells in sponges.
D) They are organelles used in the capture of prey by cnidarians.
E) They are excretory cells in sponges.

Question 35

In the history of animals,which characteristic arose after the evolution of the cnidarians?

A) Alternation between polyp and medusa
B) Three distinct body layers
C) Nematocysts
D) Gastrovascular cavity
E) Planula larva

Question 36

Which is a cnidarian group of geological importance because of its contributions to the formation of coral islands and atolls?

A) Hydrozoans
B) Scyphozoans
C) Anthozoans
D) Turbellarians
E) Ctenophores

Question 37

Which characteristic is not a feature of the sponges?

A) Gastrovascular cavity
B) No distinct tissue types or organs
C) No separation between different cell layers
D) Organization around a water canal system
E) Asymmetry

Question 38

Which feature is not a characteristic of the phoronids?

A) Fewer than 100 species
B) Active foraging and carnivory
C) Secretion of chitinous tubes
D) Possession of a lophophore
E) Length ranging from 5-25 cm

Question 39

Which taxon has the largest number of described species?

A) Sponges
B) Placozoans
C) Ctenophorans
D) Cnidarians
E) Phoronids

Question 40

Which characteristic is not a feature of the ctenophores?

A) Locomotion using beating cilia
B) Early divergence from most other animals
C) Presence of mesoglea
D) Presence of a notochord
E) Diploblastic development

Question 41

An animal with bilateral symmetry,a pseudocoelom,a tubular digestive system,and a thick,multilayer cuticle is most likely a(n)

A) arrow worm.
B) flatworm.
C) annelid.
D) polychaete.
E) nematode.

Question 42

Nautiluses are unique among living cephalopods in that they have

A) an excurrent siphon.
B) eyes comparable to those of vertebrates.
C) an incurrent siphon.
D) an external chambered shell.
E) an internal shell.

Question 43

Some cephalopods have modified their excurrent siphon and mantle to allow them to

A) ingest large prey.
B) alter their buoyancy.
C) move rapidly through the water.
D) attach to a substrate.
E) become parasitic.

Question 44

You observe an animal swimming in salt water by using a periodic jet of water.It has tentacles and an external shell.It is most likely a(n)

A) brachiopod.
B) nematode.
C) gastropod.
D) annelid.
E) cephalopod.

Question 45

Animals with thin cuticles are generally restricted to moist habitats because

A) the thin cuticle causes water to be lost across the body surface.
B) there are fewer predators in these habitats.
C) these animals rely on flowing water to bring them food.
D) movement is easier for them than on dry land.
E) None of the above

Question 46

Which body part in a mollusk secretes the shell?

A) Mantle
B) Foot
C) Visceral mass
D) Radula
E) Spicules

Question 47

Some mollusks have a rasping feeding structure known as the

A) proboscis.
B) rhynchocoel.
C) radula.
D) corona.
E) mastax.

Question 48

You have found a segmented marine animal with parapodia.Which is the most inclusive group to which this organism could belong?

A) Nematodes
B) Annelids
C) Brachiopods
D) Mollusks
E) Flatworms

Question 49

Which statement about the mantle of mollusks is false?

A) It is present in all groups of mollusks except the octopuses.
B) In terrestrial gastropods it is modified into a lung.
C) It is part of a filtering device used for feeding in bivalves.
D) It is the basis of jet propulsion in cephalopods.
E) It secretes the shell that provides external protection in most molluscan groups.

Question 50

If you were given a box containing a whip scorpion,a centipede,and a crab,what phylum name should be printed on the outside of the box?

A) Crustaceans
B) Annelids
C) Arthropods
D) Onychoporans
E) Tardigrades

Question 51

If a new fossil group of arthropods were discovered,what characteristic would most likely distinguish this group from existing arthropods?

A) Number of eyes
B) Overall body size
C) Egg size
D) Number of segments
E) Position of antennae

Question 52

An animal that has a hemocoel,a chitinous exoskeleton,and a complete digestive tract is most likely a(n)

A) nematode.
B) annelid.
C) arrow worm.
D) mollusk.
E) arthropod.

Question 53

Which statement about locomotion in nematodes is true?

A) Rhythmically beating cilia move the animal forward.
B) Longitudinal muscles contract.
C) Circular and longitudinal muscles work against each other and the pseudocoelom to change the shape of the animal,moving it forward.
D) A series of hairs that project backward engage the substrate,and back-and-forth movements propel the animal forward.
E) Water expelled through special ducts moves the animal forward.

Question 54

The rigid exoskeleton of some ecdysozoans has protective and supportive advantages,but it poses which problem?

A) The exoskeleton prevents the animal from moving rapidly.
B) The exoskeleton cannot grow as the animal's body grows.
C) The animal must consume large amounts of food to support the growth of the exoskeleton.
D) The exoskeleton attracts predators.
E) The exoskeleton is vulnerable to overexposure from the sun.

Question 55

You go to the seafood market and buy a box of what are labeled "clams." Before cooking them,you place them in salt water and observe feathery organs that are repeatedly projected from between the two halves of the organisms' shells.You return them to the market and suggest that they be relabeled as

A) oysters.
B) brachiopods.
C) gastropods.
D) onychophorans.
E) cephalopods.

Question 56

The large and remarkable pogonophoran annelids live near deep-ocean hydrothermal vents where food items are scarce.These organisms,like those of many other species,are able to obtain enough nutrition by

A) conducting photosynthesis.
B) harboring endosymbiotic bacteria that fix carbon by oxidizing hydrogen sulfide and methane.
C) fixing carbon from the minerals found in the ocean's muddy floor.
D) filtering algae out of ocean water.
E) feeding on dead fish that sink to the ocean floor.

Question 57

A lophotrochozoan with eight overlapping calcareous plates and a feeding structure called a radula belongs to which group?

A) Slugs
B) Bivalves
C) Monoplacophorans
D) Gastropods
E) Chitons

Question 58

Which group includes animals with segmented coeloms?

A) Bryozoans
B) Mollusks
C) Annelids
D) Flatworms
E) Nematodes

Question 59

The molluscan body plan includes three unique,shared,derived characteristics that support the monophyly of the group: the _______,the _______,and the _______.

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

Question 60

Which organisms are hermaphroditic?

A) Nemerteans
B) Oligochaetes
C) Bryozoans
D) Flatworms
E) Mollusks

Question 61

Which statement about protostome and deuterostome evolution is true?

A) Only one lineage exploited the abundant food supplies buried in soft marine substrates.
B) Many groups in both lineages developed elaborate structures for extracting prey from the air.
C) Both groups invaded land and evolved into very large terrestrial animals.
D) Both lineages are mostly sessile.
E) In both lineages,a coelomic cavity evolved and became divided into compartments that allowed better control of body shape and movement.

Question 62

The diversification of insects about 450 million years ago corresponded with

A) the appearance of the first land plants.
B) the evolution of cartilaginous fish.
C) the extinction of the dinosaurs.
D) changes in the CO₂ concentration of the atmosphere.
E) None of the above

Question 63

Butterflies belong to which order of winged insects?

A) Lepidoptera
B) Coleoptera
C) Diptera
D) Trichoptera
E) Isoptera

Question 64

A very small animal (about 0.3 mm in length)with fleshy,unjointed legs and living in marine sand is most likely a(n)

A) tardigrade.
B) onychophoran.
C) chelicerate.
D) crustacean.
E) hexapod.

Question 65

Which group of crustaceans bears a superficial resemblance to bivalves?

A) Barnacles
B) Copepods
C) Isopods
D) Decapods
E) Water fleas

Question 66

Which statement about spider webs and threads is false?

A) The webs can function as a home.
B) The threads are produced by modified abdominal appendages connected to internal secretory glands.
C) The threads are composed primarily of carbohydrates.
D) The webs function as a snare for catching prey.
E) The threads provide safety lines for climbing.

Question 67

Wings evolved _______ in protostomes.

A) once
B) twice
C) three times
D) four times
E) many times,independently

Question 68

Which statement about the tracheal system in insects is true?

A) Tracheae are used for water transport.
B) Tracheae penetrate virtually every part of an insect's body.
C) Tracheae extend through a single tube to an insect's mouth.
D) Tracheae provide carbon dioxide to the insects' tissues.
E) Tracheae extend from external openings to the wings.

Question 69

Living deuterostomes comprise three clades: the echinoderms,the chordates,and the

A) urochordates.
B) cephalochordates.
C) hemichordates.
D) vertebrates.
E) tetrapods.

Question 70

The _______ have bodies that are divided into two parts: a head region that bears two pairs of appendages modified to form mouthparts,and a trunk region that often has four pairs of walking legs.

A) chelicerates
B) crustaceans
C) hexapods
D) nematodes
E) myriapods

Question 71

Organisms of which group are probably most similar to ancestral arthropods?

A) Chelicerates
B) Nematodes
C) Onychophorans
D) Crustaceans
E) Trilobites

Question 72

_______ can survive for at least 10 years in a dormant,dehydrated state.

A) Myriapods
B) Onychophorans
C) Pycnogonids
D) Tardigrades
E) Trilobites

Question 73

Which marine arthropods are so numerous that they are thought to be the most abundant of all such organisms?

A) Crustaceans
B) Millipedes
C) Nematomorphs
D) Barnacles
E) Apterygotes

Question 74

Insects whose hatchlings are sufficiently similar to the adult form to be easily identifiable are those that have

A) instars.
B) neopterous development.
C) accelerated development.
D) incomplete metamorphosis.
E) complete metamorphosis.

Question 75

The centipedes and millipedes belong to which group?

A) Hexapods
B) Arachnids
C) Chelicerates
D) Annelids
E) Myriapods

Question 76

One difference between the protostomes and deuterostomes is that only the deuterostomes evolved

A) structures for filtering food from water.
B) wormlike burrowing forms.
C) adaptations needed for invasion of the land.
D) large terrestrial species.
E) jointed appendages for improved locomotion.

Question 77

The most diverse (specious)group of insects consists of the

A) grasshoppers and crickets.
B) ants,bees,and wasps.
C) lice.
D) beetles.
E) thrips.

Question 78

Which statement about insect wings is true?

A) The insect wing may have evolved from an ancestral appendage similar to that of modern spiders.
B) Development of the insect wing is governed by the expression of a gene that is different from the one that governs the crayfish appendage.
C) The pdm gene is expressed in both the wings and legs of insects.
D) Development of the insect wing and development of the crayfish thorax are controlled by the pdm gene.
E) The pdm gene seems to have appeared only recently in evolution,after the divergence of crustaceans and hexapods.

Question 79

Which arthropod group includes the dragonflies?

A) Myriapods
B) Trilobites
C) Chelicerates
D) Crustaceans
E) Hexapods

Question 80

The evolution of a chitinous exoskeleton affected many aspects of arthropod evolution.The aspect that was least affected was the

A) division of labor among the body parts.
B) mode of locomotion.
C) pattern of growth.
D) system of gas exchange.
E) mode of digestion.