chapter 21 questions

Flatworms, tapeworms, and flukes belong to the phylum

Platyhelminthes.

Animals that have ______ are called vertebrates, and those without are called invertebrates.

backbones

The ______ are the most numerous of all fishes.

bony fishes

The first animals likely arose from aquatic protists called ______, which resemble collar cells of sponges.

choanoflagellates

Endothermy requires an enormous amount of ______, which explains why birds and mammals must eat so much more food than ectotherms.

energy

Swim bladders and lungs evolved from outgrowths of the

esophagus.

Spiders, scorpions, and horseshoe crabs are arthropods called chelicerates, meaning they have

grasping, clawlike mouthparts.

Select all of the following that have gills and a cranium but lack jaws.

hagfishes lampreys

Select all of the correct statements about aquatic vertebrates called fishes.

have jaws cartilaginous or bony skeleton use gills for respiration

Both earthworms and leeches

have segmented bodies.

All animals are multicellular,

heterotrophic, and eukaryotic.

Monotremes are mammals that ______, while marsupials and placental mammals ______.

lay eggs; are live-bearing

Select all the main groups of nonavian reptiles.

lizards and snakes tuataras turtles and tortoises crocodilians

Cnidarians are organisms found mostly in ______ habitats.

marine

Select all the characteristics that distinguish sponges from other animals.

no true tissues asymmetrical body in some individuals

Turtles and tortoises, lizards and snakes, tuataras, and crocodilians are the four main groups of

nonavian reptiles.

In cnidarians, what lies between the outer ectoderm and inner endoderm of the body?

noncellular mesoglea

Most animals reproduce

sexually

Select all the characteristics of insects.

three body sections six legs usually two pairs of wings mandibles

Select all the features of mollusks.

three germ layers mantle terrestrial and aquatic species

Select all of the following that are examples of arthropods.

ticks mosquitoes termites bees shrimp

Select all the chordates that have neither a cranium nor vertebrae.

tunicates lancelets

What group contains 60,000 species, most of which are vertebrates?

Chordates

The second largest animal phylum is called Phylum ______, which includes chitons, clams, scallops, snails, nudibranchs, octopuses, squids, and nautiluses.

Mollusca

Select all of the following that are reptiles.

alligators and crocodiles lizards turtles and their relatives snakes

What evolved in the ancestor of reptiles and mammals that protected a developing embryo from drying out on land?

amniotic egg

Having a denser skeleton to withstand the force of gravity, a three-chambered heart, more acute vision, and lungs were all features that evolved in the ____and allowed them to live part of their life on land, although they are still tied to water for reproduction.

amphibians

Frogs and toads, salamanders and newts, and caecilians are the three groups of

amphibians.

What type of animal is segmented and has protostome development?

annelid

Nematodes are more closely related to ______ than to other phyla because both must shed and replace their tough external covering several times during development.

arthropods

What group of animals is the most successful, in terms of numbers of species and diversity of forms?

arthropods

Select all of the following characteristics of the flatworms, phylum Platyhelminthes.

bilateral symmetry protostome development three germ layers

Radial and bilateral are two terms used to describe the ______ of an animal.

body symmetry

Select all the characteristics of earthworms.

bristles on each segment ingest soil and eliminate indigestible particles saddlelike cocoon near head to protect eggs

Sharks, skates, and rays are jawed fishes with skeletons composed of

cartilage.

The largest known invertebrate is the colossal squid, a member of what mollusk class?

cephalopods

Grasping, clawlike mouthparts of spiders and scorpions are called

chelicerae.

Three subphyla of arthropods have mandibles, which are

chewing, jawlike mouthparts.

A notochord, a dorsal hollow nerve cord, pharyngeal pouches, and a postanal tail are features that are found at some point during the lives of animals called

chordates.

Mostly marine animals with radial symmetry, two germ layers, and stinging cells are called ______, which include jellyfishes, hydras, corals, and sea anemones.

cnidarians

Corals, sea anemones, and jellyfish are all animals called

cnidarians.

A(n) ____ is a fluid-filled body cavity that forms completely within the mesoderm during embryonic development in some eumetazoans.

coelom

Flexibility in movement of the body is a chief advantage to having a type of body cavity called a

coelom.

A mouth and an anus are characteristic of a(n) ______ digestive system.

complete

Select all of the ways that arthropods influence humans and ecosystems.

control pest populations transmit diseases produce honey and silk pollinate plants

Hagfishes and vertebrates are both

craniates.

A bony or cartilage-rich ______ surrounds and protects the brain in most chordates.

cranium

Select all of the following that are means of locomotion used by adult mollusks.

crawling on a mucous trail using a muscular foot burrowing into the sand with a muscular foot "jet propulsion" by squirting water from a siphon

Mandibulates that have two pairs of antennae and that are mostly aquatic organisms are called

crustaceans.

Select all the adaptations in amphibians that allowed them to become successful on land.

denser skeleton three-chambered heart eyelids and acute hearing legs simple lungs

Select all of the habitats where insects are found.

desert marsh grassland seashore

In animals, a complete ______ tract has two openings, one at the beginning called the mouth and one at the end called the ______.

digestive; anus

An animal that resembles a small version of the adult at hatching or birth exhibits ______ development, whereas an animal that spends part of its life in immature stages, such as larvae, exhibits ______ development.

direct; indirect

Animals that undergo ____ development do not have a larval stage; instead, they resemble a smaller version of an adult at hatching or birth. Animals that undergo ____ development spend part of their lives in larval stages.

direct; indirect

Select all the features present in tunicates and lancelets at some point in their life.

dorsal nerve cord pharyngeal slits notochord

Select the four distinguishing features that all chordates have at some time during their lives.

dorsal, hollow nerve cord postanal tail notochord pharyngeal pouches or slits

Animals with deuterostome development, bilateral symmetry as larvae, and five-part radial symmetry as adults are called

echinoderms.

What type of organism must rely on behaviors and the environment, rather than its own metabolism, to adjust its temperature?

ectotherm

Select all the features present in arthropods.

exoskeleton that must be shed jointed appendages segmentation

In animals, ______ fertilization occurs outside the body, and ______ fertilization occurs within the female animal body.

external; internal

In which group of vertebrates did jaws and a bony vertebral column arise?

fishes

Chordates that have jaws, vertebrae, gills, and paired fins are called

fishes.

One advantage of having a coelom is

flexibility in movement.

Insects were the first animals to

fly.

While cephalopod mollusks move by propelling water out of the mantle cavity, snails, slugs, and bivalves use their muscular ______ to glide or burrow.

foot

Select all of the characteristics of cnidarians.

gastrovascular cavity true tissues stinging cells called cnidocytes radial symmetry

Ectoderm, endoderm, and mesoderm are the three primary

germ layers in many animal embryos.

Jaws are a vertebrate feature that function in

grasping food.

Select all of the following that are characteristic of animals.

heterotrophic multicellular blastula stage in development cells bind to extracellular matrix

Select all of the anatomical features of bony fishes.

hinged gill coverings typically have a swim bladder bony skeletons reinforced with calcium phosphate lateral line

Select all the unique structures made of keratin that are found in mammals.

hooves hair nails

Animals with a complete digestive tract include

humans.

In all mollusks, muscles pull against a(n) ______ to produce movement.

hydrostatic skeleton

A gastrovascular cavity occurs in animals with a(n)

incomplete digestive tract.

Arthropods that have mandibles, six legs, one pair of antennae, three body regions, and sometimes two pairs of wings are called

insects.

Of the 1,300,000 described species of animals, the vast majority are

invertebrates.

Select all of the characteristics shared by hagfishes and lampreys.

jawless gills head with sensory structures cranium

Many vertebrates have bones that frame the entrance to the mouth called ______, which developed from skeletal elements that supported gill slits near the mouth of fish.

jaws

Select all the features that arose in fish and had profound affects on vertebrate evolution.

jaws robust fins that eventually evolved into limbs segmented backbone

In mammals, hair is made of ______ and functions in ______.

keratin; conserving body heat

Select all the examples of mandibulates.

lobsters crabs insects centipedes millipedes

What respiratory organ of terrestrial vertebrates is homologous with swim bladders of bony fishes?

lungs

The vertebrate group called ______ includes horses, wolves, cats, humans, cows, mice, deer, pigs, and bats.

mammals

Monotremes, which lay eggs, and marsupials and placentals, which are live-bearing, are three types of vertebrates called

mammals.

Infant mammals are nourished by their mother's milk, which is produced in the

mammary glands.

Chewing, jawlike mouthparts found in some arthropods are called

mandibles.

Millipedes and centipedes, insects, and crustaceans are three main groups of

mandibulates.

The ____ is a fold of tissue that secretes a shell in most species of mollusks.

mantle

What body region secretes a calcium carbonate shell in many mollusk species?

mantle

Of the three groups of mammals, which one carries the young in a pouch during development?

marsupials

The amnion, chorion, and allantois are the three ______ found inside an amniotic egg.

membranes

The coelom is a fluid-filled cavity that forms completely within the ______ during embryonic development of some bilaterally symmetrical animals.

mesoderm

Select the three embryonic germ layers present in all eumetazoans except jellyfishes and their relatives.

mesoderm ectoderm endoderm

Unsegmented roundworms include the

nematodes.

Select all the groups of amphibians.

newts and salamanders frogs and toads caecilians

Select the two main clades used by biologists to describe animals without true tissues and animals with true tissues

parazoans eumetazoans

In what group of mammals are young nourished by a placenta inside the mother's uterus during development?

placentals

What mammal group is currently the most diverse and is also called the eutherians?

placentals

Select all of the roles that mammals play in ecosystems and human populations.

predators source of leather and wool source of milk transmit diseases to humans

Animals arose from a type of flagellated

protist.

Arthropods are characterized by

protostome development and jointed appendages.

In bilaterally symmetrical animals, the mouth forms first in animals with ______ embryonic development, and the anus forms first in animals with ______ embryonic development.

protostome; deuterostome

A(n) ______ is a body cavity that is lined partly with mesoderm and partly with endoderm.

pseudocoelom

Select all of the characteristics of Phylum Echinodermata.

radial symmetry in adults deuterostome development closest animal relatives to chordates bilateral symmetry in larvae

In animals, segmentation is the division of an animal body into

repeated parts.

Molecular, fossil, and anatomical evidence indicates that birds are a type of

reptile.

Select all of the following that are members of phylum Cnidaria.

sea anemones hydras jellyfishes corals

Select all of the following that are cartilaginous fish.

skates sharks rays

The function of the cranium in chordates is to

surround and protect the brain.

Select the two functions of the vertebrae in vertebrates.

surround and protect the spinal cord provide attachment points for muscles

Endotherms regulate their body temperature mostly using heat generated by

their metabolism.

Select the main groups of arthropods.

trilobites chelicerates mandibulates

The five subphyla of arthropods include three subphyla of mandibulates, one subphylum of chelicerates, and one subphylum containing the 17,000 species of extinct

trilobites.

Crustaceans have variable body forms, but all have

two pairs of antennae.

A muscular foot, visceral mass, and a mantle are body regions common to all

A muscular foot, visceral mass, and a mantle are body regions common to all

The phylum of segmented worms is called ______, and includes earthworms, leeches, and polychaetes (marine segmented worms).

Annelida

Animals that do not have true tissues are classified as ______, while animals that do have tissues are called eumetazoans.

Parazoa

Cnidarians are in the group ______, which is characterized by radial symmetry and two germ layers during embryonic development.

Radiata

Vertebrate animals that can live on land but also have characteristics that tie them to fresh water are known as

amphibians.

Vertebrates with a three-chamber heart, somewhat efficient lungs, and a life cycle tied to water are called

amphibians.

What amniote group is now included among the reptiles?

birds

What vertebrate group is characterized by four-chambered hearts, feathers, and endothermy?

birds

Select all the endotherms.

birds mammals

Molecular evidence indicates that the reptile clade in the phylogeny of chordates includes snakes, lizards, turtles, crocodiles, and

birds.

Animals that have true tissues are grouped into a clade called the

eumetazoans.

Lungs present in some vertebrates allow

exchange of gases with air.

Animal cells secrete a surrounding ______ that is a mixture of proteins and other molecules.

extracellular matrix

Select all the characteristics of birds.

feathers four-chambered heart lay amniotic eggs endothermic

Protostomes that have bilateral symmetry and three embryonic germ layers, but that do not possess a coelom or pseudocoelom, are called

flatworms.

Incomplete digestive systems have one opening. Digestion occurs in a

gastrovascular cavity.

In animals with incomplete digestive systems, digestion is done in the ______ cavity, which has ______ opening(s).

gastrovascular; one

Protostomes and deuterostomes have embryonic development patterns that differ in terms of what forms from the first indentation of the

gastrula.

What characteristic do nematodes and arthropods have in common?

molting of cuticle

Select all the examples of ectotherm animals.

most nonavian reptiles most amphibians invertebrates fishes

control pest populations transmit diseases produce honey and silk pollinate plants

nematodes

At some point in their life cycle, all chordates have a postanal tail, ______, hollow nerve cord, and ______.

notochord; pharyngeal slits or pouches

Eumetazoans have true tissues, and different types of tissue can interact to form ______, which increase efficiency of body functions and complexity of movement.

organs

Nematodes in the phylum Nematoda are

roundworms

What animals have a pseudocoelom?

roundworms

Select all of the following that are in the group Bilateria.

roundworms chordates flatworms arthropods

Select all the characteristics of annelids called leeches

saddlelike cocoon near head to protect eggs feed on blood of vertebrates sucker on each end live in freshwater

What animal group lacks true tissues and includes species that are asymmetrical?

sponges

Animals called the parazoans include the ______ and lack true ______.

sponges; tissues

Select all of the following that are members of the phylum Platyhelminthes.

tapeworms flukes marine flatworms planarians

Endotherms regulate their body temperature mostly using heat generated by Multiple choice question.

their metabolism.

The invertebrate chordates are the

tunicates and lancelets.

In vertebrates, the series of small bone or cartilage structures that make up the backbone are called

vertebrae.

Protecting the spinal cord and providing attachments for muscles are the two functions of the

vertebrae.

Vertebrates are distinguished by the presence of a

vertebral column, or backbone.

In what type of chordate is the spinal cord surrounded by a backbone composed of cartilage or bone?

vertebrates

Select all the animals that have segmented bodies.

vertebrates earthworms insects

Select all the chordates that have a cranium.

vertebrates hagfish

Select the three major body regions present in all mollusks.

visceral mass mantle muscular foot