Chapter 33 & 34 - Animal Diversity and Invertebrates

Of the organisms listed, which are members of the Mollusca phylum? - Chitons - Tunicates - Snails - Clams - Brachiopods

- Chitons - Snails - Clams

The mollusks constitute a large phylum with many different types of organisms. Associate the following attributes with the four different groups of mollusks. a. cephalopoda

- tentacles surrounding the mouth - closed circulatory system - jet propulsion via siphon

An estimated ______ species of animals await discovery and classification.

2-5 million

What approximate fraction of all described species are arthropods?

3/4

How many legs do insects have?

6

What is a coelom?

A fluid-filled body cavity.

Match each phylum listed below with its distinguishing characteristics. d. Arthropoda

Bilateral symmetry; triploblastic; segmented; a hard cuticle composed primarily of chitin; ecdysis

What phyla are included in the Deuterostomia clade?

Chordata Echinodermata

Which of the following is the most likely ancestor from which animals evolved? - Colonial flagellated protist - Colonial flagellated bacterium - Solitary flagellated bacterium - Solitary flagellated protist

Colonial flagellated protist

Cephalization is

Concentration of sensory organs and nerve cells at the anterior end of an animal

What animal phylum includes members that are hermaphroditic, often bioluminescent, live in marine environments, and use cilia for movement?

Ctenophora

All animals belong to the domain

Eukarya

Insects belong to the class

Insecta

What group of organisms exhibits a great deal of diversity in wing and mouthpart structure, sociality, and type of development, affording them a great deal of success in all terrestrial environments?

Insects

The subphylum hexapoda includes:

Insects and relatives

Match each phylum listed below with its distinguishing characteristics. e. Echinodermata

Larvae exhibit bilateral symmetry, adults radial; triploblastic; tube feet; deuterostome development; endoskeleton composed of ossicles Larvae exhibit bilateral symmetry, adults radial; triploblastic; tube feet; deuterostome development; endoskeleton composed of ossicles

Organisms that undergo protostome development and possess either a lophophore or a distinct trochophore larval stage are members of what major animal clade?

Lophotrochozoa

In insects, excretion is accomplished by delicate projections from the digestive tract that protrude into the hemolymph. What are these projections called?

Malpighian tubules

The subphylum Myriapoda includes which of the following?

Millipedes and centipedes

Small, thin worms that usually range from 1 mm to 5 cm in length.

Nematoda

You are observing the embryonic development of a new species in your laboratory. This species has indeterminate development. You note a mutation in which one of the blastomeres (early cells) mutates and loses its function. What do you hypothesize would happen to this being?

Nothing—the remaining blastomeres would accommodate the formation of the necessary structures of the embryo.

Which of the following best describes the circulatory system of arthropods?

Open: Hemolymph is pumped from the tubelike heart to the hemocoel, where nutrients diffuse into tissues.

What are spiracles?

Openings in the body cavity where the trachea are exposed to outside air. breathing holes

To which phylum do flatworms belong?

Platyhelminthes

A previously unknown animal is being studied so that it can be classified. It is an invertebrate, triploblastic, dorsoventrally flattened, acoelomate, and has flame cells. Which phylum would you place it in?

Platyhelminthes.

Sponges are members of the phylum

Porifera

One of the most commonly used nucleotide sequences obtained during molecular phylogenetic analysis is:

SSU rRNA

In a sponge, what are the skeletal structures composed of protein, silica, or calcium carbonate called?

Spicules

Which of the following is true of animals within the group Bilateria? - They can be divided equally by any longitudinal plane through the central axis. - They are asymmetrical. - They have a left and right side that are mirror images of each other. - They will be divided into mirror image when cut along any plane through the central point

They have a left and right side that are mirror images of each other.

Multicellular heterotrophs lacking cell walls are known as

animals, metazoans, or animalia

Animal phyla display different forms of symmetry and tissue specialization. Drag the following phyla into the proper cell of this table according to their symmetry and tissue layer condition. c. Porifera

asymmetric

Match each group of arthropods to its associated subphylum. a. spiders, scorpions, ticks, mites

chelicerata

Match each representative to the subphylum to which it belongs. a. horseshoe crabs

chelicerata

The exoskeleton is made of ____________ , which is extremely strong and flexible.

chitin

The closest living relatives of animals are the

choanoflagellates.

Germ layers are

embryonic layers with different developmental potentials.

Triploblastic refers to animals that

have three germ layers

In the circulatory system of arthropods, the______ is pumped from the heart into the aorta or short arteries and then into open sinuses that coalesce to form the ________.

hemolymph; hemocoel

A(n) ______ is an individual that is capable of producing both sperm and eggs.

hermaphrodite

Insects are athropods that are members of the subphylum

hexapoda

Match each group of arthropods to its associated subphylum. c. beetles. grasshoppers, flies, mosquitoes

hexapoda

Match each representative to the subphylum to which it belongs. b. insect

hexapoda

Some invertebrate organisms possess a crown of tentacles called a(n) ______ that functions in feeding and respiration.

lophophore

Molecular studies indicate that the protostomes are divided into two clades: the ______ and the _____.

lophotrochozoa; ecdysozoa

Ecdysozoans are named as such because they all undergo

molting

Animals are:

multicellular heterotrophs without cell walls

Mites and ticks may be best described as:

often parasitic; fused cephalothorax and abdomen

Which of the following organisms have a pseudocoelom and a ciliated crown?

rotifers

Arthropods with pedipalps that are modified into large claws and an abdomen that tapers into a venom-injecting stinger are:

scorpions

The phylum Annelida consists of the _____ worms.

segmented

All animals have cell junctions. true or false

true

The exoskeleton protects against ____________ loss.

water

The arthropods are perhaps the most successful phylum on Earth. Associate the following attributes with the four subphyla of arthropods. c. hexapoda

- head, thorax, abdomen - three pairs of legs - mouth parts modified fr different types of feeding

The arthropods are perhaps the most successful phylum on Earth. Associate the following attributes with the four subphyla of arthropods. b. myriapoda

- highly segmented trunk - some have one pair of walking legs per segment - some have two pairs of walking legs per segment

Which of the following organisms are chelicerates? - Centipedes - Mites - Millipedes - Fleas - Lice - Ticks - Spiders - Scorpions

- mites - ticks - spiders - scorpions

Select all of the following that are names of immature stages in various animals. - nauplius. - trochophore. - caterpillar. - nymph. - swimmeret.

- nauplius. - trochophore. - caterpillar. - nymph.

Which creatures belong to the Phylum Platyhelminthes? - planarians. - monogeneans. - tapeworms. - trematodes. - ctenophores.

- planarians. - monogeneans. - tapeworms. - trematodes.

Chordates possess several distinguishing characteristics that separate them from other animal groups. Check all of the features that one would use to classify members into this phylum. - postanal tail. - cranium. - pharyngeal slits. - notochord. - dorsal hollow nerve cord. - vertebral column.

- postanal tail. - pharyngeal slits. - notochord. - dorsal hollow nerve cord.

The lophophore, the structure characteristic of lophophorates, plays important roles in which of the following processes? - Protection - Respiration - Reproduction - Feeding - Movement

- respiration - feeding

Select all of the arthropods that are often ectoparasitic and that have a cephalothorax and abdomen that are fused. - insects - ticks - spiders - ostracods - copepods - mites

- ticks - mites

The arthropods are perhaps the most successful phylum on Earth. Associate the following attributes with the four subphyla of arthropods. d. crustacea

- usually marine - body of two or three parts - chewing mouth parts

What are lophophores?

-A horseshoe-shaped structure bearing ciliated tentacles around the mouth in certain small marine invertebrates. functioning in suspension feeding adults

Match each major arthropod subphylum to its defining characteristics. c. Hexapoda

Body comprised of head, thorax, and abdomen; mouthparts modified for food type; usually two pairs of wings and three pairs of legs; usually terrestrial

Match each major arthropod subphylum to its defining characteristics. d. Crustacea

Body comprised of two or three parts; three or more pairs of legs; chewing mouthparts; usually marine

Many arthropods possess tagmata. What are they?

Body segments that have become fused into functional units

Which of the following statements is true regarding echinoderms and chordates? - Both have exoskeletons and undergo deuterostome development - Both have exoskeletons and undergo protostome development. - Both have endoskeletons and undergo protostome development - Both have endoskeletons and undergo deuterostome development

Both have endoskeletons and undergo deuterostome development

Spiders, scorpions, mites, and ticks are members of the arthropod subphylum:

Chelicerata

Crustaceans that have ten walking legs, the first of which is modified to bear large claws, are members of what taxonomic order?

Decapoda

Which of the following undergo molting? - Lophotrochozoans - Polyplachophorans - Ecdysozoans - Bryozoans - Cnidarians

Ecdysozoans

What phylum of organisms have spiny skin, bilateral symmetry only as larvae, modified radial symmetry as adults, and possess a water vascular system?

Echinodermata

True or False: Like insects, chelicerates have a body consisting of three tagmata: a head, thorax, and abdomen.

False

Which animal phyla lack tissue differentiation?

Porifera only

Match each phylum listed below with its distinguishing characteristics. b. Cnidaria

Radial symmetry; diploblastic; polyp and medusa forms; stinging cells

Which of the following groups of animals are asymmetric? - Nematodes - Annelids - Sponges - Jellyfish - Rotifers

Sponges

What are cnidocytes?

Stinging cells that can be used in defense or prey capture

________ refers to the existence of balanced proportions of the body on either side of a median plane.

Symmetry

If two otherwise dissimilar organisms share similar genomic DNA, to what would you attribute the genomic similarity?

The two taxa are more closely related than formerly believed.

What is the role of Malpighian tubules in insects?

They absorb nitrogenous wastes from the hemolymph, to be subsequently excreted

What is the function of trachea?

They allow gas exchange.

Which of the following accurately defines the independent visual units that make up the compound eyes of arthropods?

They are called ommatidia

What is a characteristic of most animals?

They have Hox genes.

What is the primary characteristic that groups phyla within the Ecdysozoa?

They shed their exoskeletons.

In your observations of a new rotifer species, you note that diploid females can lay diploid eggs that in turn become diploid female adults. What do you conclude about this behavior?

This is asexual reproduction by way of parthenogenesis.

What sentence best describes the feeding mechanism of a sponge?

Tiny food particles are trapped by flagellated cells as water is drawn through pores in the body of the sponge and exits via the osculum.

The invertebrate group most closely related to the vertebrates is the

Urochordata.

An invertebrate animal is one that does not have:

a backbone

An animal is an organism best described as being:

a multicellular heterotroph that lacks cell walls and is motile at some point during its life cycle

What critical innovation was likely the most influential in allowing arthropods to eventually colonize land?

an exoskeleton

Myriapods have one pair of ______ on the head and _____ pairs of appendages that are modified as mouth parts, including mandibles that act as jaws.

antennae; three

Cnidarians are found in ______ environments and possess ______ embryonic germ layers.

aquatic; two

Segmented organisms with jointed legs and a hard exoskeleton composed of chitin make up the phylum

arthopoda

Hexapoda, Chelicerata, Trilobita, Myriapoda, and Crustacea are subphyla within the phylum:

arthopodia

Of all described living species present on Earth, about three-quarters are

arthropods or Arhtropoda

The exoskeleton provides ____________ for muscles.

attachment

Animals that are bilaterally symmetrical are placed in the group _____

bilateral or balateral

An animal that can be divided only by a vertical plane along the midline to create two identical halves exhibits ______ symmetry, while an animal that can be divided into two identical halves by any longitudinal plane passing through the central axis exhibits _______ symmetry.

bilateral; radial

Animal phyla display different forms of symmetry and tissue specialization. Drag the following phyla into the proper cell of this table according to their symmetry and tissue layer condition. b. Mollusca

bilaterally symmetric

Match each major arthropod subphylum to its defining characteristics. a. Chelicerata

body comprised of a cephalothorax and abdomen; six pairs of appendages (four pairs of walking legs, one pair of fangs, and one pair of pedipalps); terrestrial

Match each major arthropod subphylum to its defining characteristics. b. Myriapoda

body comprised of a head and highly segmented trunk; one or two pairs of legs per segment; terrestrial

The arthropod exoskeleton is composed of layers of chitin and protein, however, the crustacean exoskeleton is reinforced with ________ _______.

calcium carbonate

Fast-moving, carnivorous arthropods with one pair of walking legs per segment are known as

centipedes, chilopods, Chilopoda, or centipede

The arthropod exoskeleton is composed of layers of ______ and ______.

chitin; protien

Members of the phylum Rotifera get their name from their:________, which have a known as a corona that is used in locomotion and feeding?

ciliated crown

Fill in the names of the appropriate phyla for the distinguishing characteristics listed below. - Phylum _______: Diploblastic; gastrovascular cavity for extracellular digestion; radial symmetry; polyp and medusa forms; stinging cells - Phylum _______: Deuterostome development; notochord; pharyngeal slits; hollow dorsal nerve cord; muscular post-anal tail - Phylum _____: Deuterostome development; water vascular system; endoskeleton composed of ossicles; tube feet - Phylum ______: Bilateral symmetry; protostome development; body plan made up of mantle, visceral mass, and foot; some species have a shell

cnidaria chordata echinodermata mollusca

Cnidarians have stinging cells called _______ which contain powerful capsules called nematocysts. These are used in prey capture and defense.

cnidocytes

In a bilaterally symmetrical animal, a(n) ________ is a fluid-filled body cavity, which develops entirely within the mesoderm.

coelom

Match each group of arthropods to its associated subphylum. d. crabs, lobsters, barnacles

crustacea

Match each representative to the subphylum to which it belongs. c. shrimp

crustacea

A nauplius is the first larval stage of many ______, which is very different in appearance from the adult form.

crustaceans

Echinoderms are classified as Bilateria, but although they start out as bilateral larvae, they change into radially symmetrical adults. You might hypothesize that their genes controlling the development of radial symmetry are

different from those controlling development of symmetry in all other radially symmetrical animals.

To grow the arthropod must undergo ____________ , during which time they are extremely vulnerable to predators.

ecdysis

In arthropods, the chitinous _______ provides protection and waterproofing, in addition to serving as an attachment site for the internal muscles.

exoskeleton or cuticle

The ________ may have enabled many arthropods to conserve water and colonize land.

exoskeleton or cuticle

A jellyfish displaying radial symmetry can be divided into no more than three lines of symmetry. true or false

false

All nonradiate animals, including the sponges, display bilateral symmetry. true or false

false

Cnidarians can detect and react to prey using a centralized nervous system. true or false

false

Echinoderms have an exoskeleton. true or false

false

The epidermis, mesoglea, and gastrodermis represent the triploblastic condition found in all cnidarians. true or false

false

Because the cuticle impedes the diffusion of gases through the body surface, arthropods possess special organs that permit gas exchange. In aquatic arthropods, these consist of feathery ______ that have an extensive surface area in contact with the surrounding water. Terrestrial species have a highly developed system of ______.

gills; trachea

Match the molluscan body part to its function. b. mantal cavity

houses gills

Match the molluscan body part to its function. a. visceral mass

houses organs

Insects are members of the arthropod class:

insecta

The first animals did not have a backbone. These types of animals are collectively called

invertebrates

The use of molecular data to construct phylogenetic trees is based on the premise that more closely related species exhibit _______ sequence differences than distantly related ones.

less

Some arthropods have long bodies, two pairs of walking legs per segment, and defend themselves through bright coloration, coiling, or ejecting toxic, repellent secretions. These arthropods are called

millipedes, Diplopoda, millipede, or Diplopod

In the subphylum Myriapoda, the _______ have two pairs of legs per segment, while the ______ have one pair of legs per segment.

millipedes, Diplopoda, or millipede centipedes, Chilopoda, or centipede

The gene that encodes the small subunit of ribosomal RNA is often used for:

molecular phylogenetic analysis

Snails, clams, octopuses, and chitons are all members of the phylum

mollusca

Match the molluscan body part to its function. c. foot

movement

As the arthropod grows, the exoskeleton must become thicker to bear the force of the ____________ .

muscles

Match each group of arthropods to its associated subphylum. b. millipedes, centipedes

myriapoda

Match each representative to the subphylum to which it belongs. d. millipedes

myriapoda

The first larval stage of many crustaceans, that looks much different from the adult form, is known as a(n):

nauplius

The independent visual units that make up the compound eyes of arthropods are known as

ommatidia

Arthropods have compound eyes composed of ______ that generate a mosaic-like image of the environment. Some species also have simple eyes called ________ that are only able to distinguish light and dark.

ommatidia; ocelli

Adult echinoderms display __________ symmetry; however, their larvae display ____________ symmetry.

pentaradial; bilateral.

Most cnidarians exist as two different body forms: the ______ and the _____.

polyp; medusa

In the figure, the jellyfish (left) is an example of animal that exhibits _______ symmetry, and the crab (right) is an example of an animal that exhibits ______ symmetry.

radial (symmetric on multiple lines) bilateral (symmetric on only one line.

You are examining a new animal species. You find that you can pass a line through any longitudinal plane and find equal halves. Evaluate the symmetry of this animal.

radial.

Animal phyla display different forms of symmetry and tissue specialization. Drag the following phyla into the proper cell of this table according to their symmetry and tissue layer condition. a. Cnidaria

radially symmetric

All of the following are functions of the arthropod exoskeleton EXCEPT - protection - muscle attachment - radiation resistance - water conservation

radiation resistance

The protrusible rasping organ in a mollusk's mouth that is used to scrape food from the substrate is

radula

Match the molluscan body part to its function. d. mantal

secretes the shell

An animal that is attached to the substrate and cannot move from one place to another is said to be

sessile

Most cnidarians possess two distinct body forms: the polyp, which is ___________, and the medusa, which is ___________.

sessile; motile.

In sponges, some amoebocyte cells can form a tough skeletal fibers that support the body. This skeleton consists of sharp structures formed of protein, calcium carbonate, or silica, called

spicules

In terrestrial arthropods, pores in the cuticle called _______ facilitate gas exchange.

spiracles

Members of the phylum _______ are not generally thought to possess specialized tissue types or organs, although they may have several distinct types of cells.

sponges

What organisms make up the Porifera phylum?

sponges

Some of the earliest-diverging animals, such as ______, had no plane of symmetry.

sponges or Parazoa

The feeding mechanism of a sponge can be summarized as such: Water is drawn into the ______ by the beating action of ________. Small particulate matter and tiny plankton are trapped and eaten, while the water then flows out through the large opening at the top.

spongocoel; choanocytes

Animals can be divided into categories according to the type of ______ their body displays.

symmetry

In many arthropods, the body segments have become fused into functional units called

tagmata

If it were found that all animals except the Parazoa had a particular set of genes, one could conclude

that those genes probably are related to the embryonic formation of tissues.

Based on recent studies of molecular phylogeny, scientists suggest that:

the Protostomes are divided into two clades, the Ecdysozoa and Lophotrochozoa

The choanocytes have a flagellum that moves water through the sponge and a collar that extracts food particles from the water. In what group have you encountered very similar cells before?

the choanoflagellates

Extinct bottom-feeding organisms with segmented bodies divided longitudinally into three lobes, that were approximately 3-10 cm in size, make up the arthropod subphylum:

triobita

A hydrostatic skeleton has no bones or cartilage. true or false

true

Animals displaying bilateral symmetry can be divided into no more than one vertical plane at midline, where each half creates a mirror image of the other. true or false

true

Animals with radial symmetry include the phyla Cnidaria and Ctenophora. true or false

true

Cnidarians are able to capture prey by stinging them with microscopic harpoon-like projectiles released by special cells called cnidocyte. true or false

true

Cnidarians can exhibit one of two life forms: a sessile polyp and/or a free-swimming medusa form true or false

true

Cnidarians consume food brought inside the gastrovascular cavity using extracellular digestion. true or false

true

The animal kingdom is a monophyletic grouping. true or false

true

The diversification of insects is related to the diversification of food sources in the environment. true or false

true

True or false: Echinoderms and chordates are closely related, both have endoskeletons and deuterostome development.

true

Which of the following accurately describes the number of body forms exhibited by most cnidarians?

two

Which of the following statements are true of members of the phylum Nematoda? - Range in length from 1 cm to 50 cm - Also called round worms - They undergo ecdysis - Found exclusively in aquatic environments - Many species are parasitic

- Also called round worms - They undergo ecdysis - Many species are parasitic

All animal species have general characteristics in common. Check all of the characteristics that would apply to members of this kingdom. - Animal cells possess a cell wall and are quite rigid. - Animals have the capacity to move at some point in their life cycle. - Most animals undergo sexual reproduction where a small motile sperm cell unites with a larger egg cell to produce a zygote. - Not all animals are multicellular. - All animals produce diploid spores. - All animals are heterotrophs.

- Animals have the capacity to move at some point in their life cycle. - Most animals undergo sexual reproduction where a small motile sperm cell unites with a larger egg cell to produce a zygote. - All animals are heterotrophs.

You are given a new animal species to study. You note that it possesses segmentation. Based entirely on the knowledge that it is segmented, to which of these phyla might the new species belong? - Cnidaria. - Arthropoda. - Chordata. - Annelida. - Platyhelminthes.

- Arthropoda. - Chordata. - Annelida.

Indicate the correct arthropod subphylum containing each of the organisms listed below. Shrimp: _______ Butterflies: _______ Scorpions: ______ Centipedes: ______

- Crustacea - Hexapoda - Chelicerata - Myriapoda

Which of the following are characteristics of echinoderms? - Bilateral symmetry at all life stages - Protostome development - Endoskeleton composed of calcareous plates - Tube feet - Presence of a notochord - Presence of a water vascular system

- Endoskeleton composed of calcareous plates - Tube feet - Presence of a water vascular system

Which of the following are characteristics of members of the Cnidaria phylum? - Found in marine or freshwater habitats - Includes sponges - Possess three germ layers - Possess a mesoglea

- Found in marine or freshwater habitats - Possess a mesoglea

Select the characteristics of the subphylum Chelicerata. - Have bodies consisting of two tagmata - Have ten pairs of appendages - Typically predatory or parasitic - Predominantly aquatic - Fangs

- Have bodies consisting of two tagmata - Typically predatory or parasitic - Fangs

Which of the following are characteristics found in all animals? - Heterotrophic - Characteristic cell junctions - Cell walls - Presence of vertebrae - Multicellularity - Extracellular matrix

- Heterotrophic - Characteristic cell junctions - Multicellularity - Extracellular matrix

Indicate the correct arthropod subphyla indicated below: - Body with head, thorax, and abdomen; highly modified mouthparts; often possess two pairs of wings and three pairs of legs: __________ - Body of two to three parts; three or more pairs of legs; usually marine: ___________ - Body with head and highly segmented trunk; one or two pairs of walking legs per segment; terrestrial: ____________ - Body comprised of cephalothorax and abdomen; six pairs of appendages; pedipalps; predatory or parasitic: ________

- Hexapoda - Crustacea - Myriapoda - Chelicerata

What are the names of the five subphyla within the Arthropoda phylum? - Nematoda - Urochordata - Myriapoda - Hexapoda - Crustacea - Chelicerata - Trilobita - Cephalopoda

- Myriapoda - Hexapoda - Crustacea - Chelicerata - Trilobita

Which of the following include features traditionally used by biologists to classify animal diversity? - Presence/absence of central nervous system - Type of circulatory system - Number of germ layers - Type of body symmetry - Type of reproduction - Features of embryonic development

- Number of germ layers - Type of body symmetry - Features of embryonic development

Which of the following are characteristics of echinoderms? - Presence of a notochord - Presence of a water vascular system - Bilateral symmetry at all life stages - Tube feet - Endoskeleton composed of calcareous plates - Protostome development

- Presence of a water vascular system - Tube feet - Endoskeleton composed of calcareous plates

Which of the following are distinguishing characteristics of the Lophotrochozoa clade? - Protostome development - A lophophore or a distinct trochophore larval stage - A body plan consisting of a foot, visceral mass, and mantle - Pharyngeal gill slits - An endoskeleton

- Protostome development - A lophophore or a distinct trochophore larval stage

All members of the phylum Arthropoda have what characteristics?

- Segmentation - Jointed legs - An exoskeleton composed of chitin and protein

The vast diversity exhibited by the insects contributes to their great success on Earth. Insects vary in which of the following characteristics? - Structure of mouthparts - Number of legs - Wing structure - Mode of development (incomplete or complete metamorphosis) - Ability to undergo ecdysis

- Structure of mouthparts - Wing structure - Mode of development (incomplete or complete metamorphosis)

Which of the following are characteristics of centipedes? - The head has many sensory appendages, including antennae and appendages modified as mouthparts. - They are carnivores that actively pursue their prey. They generally inhabit dry, desertlike habitats. - Their venom may be powerful enough to cause pain in humans. - They have two pairs of walking legs per segment.

- The head has many sensory appendages, including antennae and appendages modified as mouthparts. - They are carnivores that actively pursue their prey. - Their venom may be powerful enough to cause pain in humans.

Describe the characteristics of the Phylum Platyhelminthes. - They are acoelomate. - They are triploblastic. - They have a complete digestive system. - They exchange respiratory gases through the body wall.

- They are acoelomate. - They are triploblastic. - They exchange respiratory gases through the body wall.

Which of the following are characteristics of scorpions? - They are generally found in tropical or subtropical regions - The young are carried on the back of the mother until their first molt - Their venom is always fatal to humans - They lay a large number of eggs, which are contained in an egg sac - They feed primarily on plants

- They are generally found in tropical or subtropical regions - The young are carried on the back of the mother until their first molt

Which of the following are characteristics of crustaceans? - Most species are hermaphroditic - They can be predators, scavengers, or filter feeders - Some larger species are economically important food sources for humans. - All species live in marine or freshwater environments - They have a nauplius larval form that differs significantly in appearance from the adult form - Eggs are carried in pouches under the mother's body

- They can be predators, scavengers, or filter feeders - Some larger species are economically important food sources for humans. - They have a nauplius larval form that differs significantly in appearance from the adult form - Eggs are carried in pouches under the mother's body

Which of the following are true of decapods? - They include the largest crustacean species - They possess modified feathery legs that are used in filter feeding, and a sessile lifestyle - Have two pairs of legs on each segment - A distinct larval form known as a trochophore - Ten walking legs, one pair of which is often modified into large claws - They are often parasites on marine fishes

- They include the largest crustacean species - Ten walking legs, one pair of which is often modified into large claws

Characteristics of the millipedes (class Diplopoda) include: - They may protect themselves by producing toxic secretions. - They may protect themselves using bright coloration to warn potential predators. - They are herbivores. - They lack antennae. - They have one pair of walking legs per segment. - They have fangs.

- They may protect themselves by producing toxic secretions. - They may protect themselves using bright coloration to warn potential predators. - They are herbivores.

Which of the following are characteristics of ctenophores? - They are commonly referred to as sponges. - Most species live in soil habitats. - They possess stinging cnidocytes for prey capture. - They secrete a sticky substance for prey capture. - Many species are bioluminescent. - They move by coordinated beating of cilia.

- They secrete a sticky substance for prey capture. - Many species are bioluminescent. - They move by coordinated beating of cilia.

Which of the following are major characteristics of members of the arthropod subphylum Trilobita? - Three tagmata: the head, thorax, and tail - A cuticle that is shed as the organism increases in size - An active predatory lifestyle with specialized claws - Chelicerae attached to venom sacs that were used in prey capture - Three lobes: an axial lobe and two pleural lobes

- Three tagmata: the head, thorax, and tail - A cuticle that is shed as the organism increases in size - Three lobes: an axial lobe and two pleural lobes

Which of the following are morphological characteristics of crustaceans? - A total of six walking legs and no additional abdominal appendages - Trachea for respiration - Two pairs of antennae - Chelicerae and pedipalps - A body plan consisting of a cephalothorax and abdomen - A nauplius larval stage that differs significantly in appearance from the adult stage

- Two pairs of antennae - A body plan consisting of a cephalothorax and abdomen - A nauplius larval stage that differs significantly in appearance from the adult stage

What is the advantage to the segmentation that is exemplified in the Phylum Annelida? - Vital structures are repeated in each segment. - The annelid may still survive if one segment is damaged. - Locomotion is more efficient. - Segments can be specialized. - The importance of segmentation is unclear.

- Vital structures are repeated in each segment. - The annelid may still survive if one segment is damaged. - Locomotion is more efficient. - Segments can be specialized.

Which characteristics are included in the Lophotrochozoan grouping? Check all that apply. - a crown of tentacles. - trochophore larvae. - deuterostome development. - outer covering that is shed.

- a crown of tentacles. - trochophore larvae.

The mollusks constitute a large phylum with many different types of organisms. Associate the following attributes with the four different groups of mollusks. b. gastropoda

- aquatic or terrestrial - coiled shell

The arthropods are perhaps the most successful phylum on Earth. Associate the following attributes with the four subphyla of arthropods. a. chelcerata

- cephalothorax and abdomen - six pairs of appendages - fangs and pedipalps

Features of the arthropod body plan include: - compound eyes composed of ommatidia - a cuticle composed of chitin and protein - a water vascular system - segments fused into tagmata - jointed appendages - a muscular foot

- compound eyes composed of ommatidia - a cuticle composed of chitin and protein - segments fused into tagmata - jointed appendages

The mollusks constitute a large phylum with many different types of organisms. Associate the following attributes with the four different groups of mollusks. d. polyplacophora

- eight-plated shell

The mollusks constitute a large phylum with many different types of organisms. Associate the following attributes with the four different groups of mollusks. c. bivalvia

- filter feeders with siphons - marine or freshwater - shells with two halves

The arthropods are the most successful group of animals; several key features explain their success. Check all of the features that one would use to classify members into this phylum. - growth takes place through ecdysis. - a rigid exoskeleton made of chitin. - closed circulatory systems. - jointed appendages. - a rigid exoskeleton made of keratin. - segments specialized into functional tagmata.

- growth takes place through ecdysis - a rigid exoskeleton made of chitin - jointed appendages - segments specialized into functional tagmata

Many insects undergo some degree of change in their body form during development. Associate the following characteristics to complete or incomplete metamorphosis. a. Complete metamorphosis

- has four stages - includes a pupa stage - immatures and adults use different food sources

Many insects undergo some degree of change in their body form during development. Associate the following characteristics to complete or incomplete metamorphosis. b. Incomplete metamorphosis

- has three stages - immatures look like mini adults - immatures are called nymphs

Molecular data suggests that the Lophotrochozoa is a new clade of bilaterally symmetric animals that originally included phyla separated by differences in body plan (those lacking a coelom, possessing a pseudocoelom, or possessing a true coelom). Check all of the phyla that are included under this new taxonomic classification. - Chordata. - Platyhelminthes. - Echinodermata. - Mollusca. - Annelida. - Ctenophora.

-Platyhelminthes - Mollusca - Annelida

Approximately how many animal species have been described so far?

1 million

Place the following steps in the history of animal life on earth in order. Begin with the first event at the top and end with the last event at the bottom. - Appearance of vertebrate animals - The post-cretaceous explosion of mammalian diversity - Appearance of invertebrate animals - Colonization of land - The Cambrian explosion of animal diversity

1. Appearance of invertebrate animals 2. The Cambrian explosion of animal diversity 3. Appearance of vertebrate animals 4. Colonization of land 5. The post-Cretaceous explosion of mammalian diversity

Members of what phylum can be described as such: segmented organisms that have a complete digestive system, a ventral nerve cord, and a coelom that acts as a hydrostatic skeleton?

Annelida

Members of what phylum have compound eyes composed of ommatidia that render a mosaic-like image of the environment?

Arthropoda

Match each phylum listed below with its distinguishing characteristics. a. porfera

Asymmetrical; no true tissues; choanocytes move water through the body wall and trap food particles Asymmetrical; no true tissues; choanocytes move water through the body wall and trap food particles

Match each phylum listed below with its distinguishing characteristics. c. Mollusca

Bilateral symmetry; triploblastic; body plan comprised of a foot, visceral mass, and mantle; some species have a shell for protection Bilateral symmetry; triploblastic; body plan comprised of a foot, visceral mass, and mantle; some species have a shell for protection

In what supergroup are animals classified?

Opisthokonta

With regard to phylogenetic trees based on morphological data and molecular data:

Phylogenies based on molecular data tend to be more accurate

Morphological and developmental features typically used to classify animals into taxonomic groups include: - type of body symmetry, number of germ layers, and mode of reproduction - presence or absence of specialized tissues, mode of nutrition, and internal versus external fertilization and development - unicellularity versus multicellularity, type of body symmetry, and number of germ layers - type of body symmetry, number of germ layers, and features of embryonic development

type of body symmetry, number of germ layers, and features of embryonic development