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