12.1 Structure and Function of Vertebrates

12.2 Fishes

12.3 Amphibians

12.4 Reptiles

12.5 Birds 12.6 Mammals

Table of ContentsChapter Preview

12.1 What Is a Vertebrate?

12.2 Fishes

12.3 Amphibians

12.4 Reptiles

12.5 Birds

12.6 Mammals

Chapter 12 Preview Questions

1. A group of similar cells that perform a specific function is called a(n)

a. organ.b. tissue.c. organ system.d. organism.

Chapter 12 Preview Questions1. A group of similar cells that perform a specific function is called a(n)

a. organ.b. tissue.c. organ system.d. organism.

Chapter 12 Preview Questions

2. The major cause of extinction of species isa. a change in the environment.b. new diseases.c. over-killing by predators.d. competition with other species.

Chapter 12 Preview Questions

2. The major cause of extinction of species isa. a change in the environment.b. new diseases.c. over-killing by predators.d. competition with other species.

Chapter Preview Questions

3. The term for the extinction of many organisms at the same time is

a. Permian extinction.b. Pangaea.c. Cambrian explosion.d. mass extinction.

Chapter 12 Preview Questions

3. The term for the extinction of many organisms at the same time is

a. Permian extinction.b. Pangaea.c. Cambrian explosion.d. mass extinction.

Chapter 12 Preview Questions

4. Most animals reproducea. sexually only.b. asexually only.c. with alternating sexual and

asexual stages.d. by binary fission.

Chapter 12 Preview Questions

4. Most animals reproducea. sexually only.b. asexually only.c. with alternating sexual and asexual stages.d. by binary fission.

Two friends are looking at fishes in an aquarium. One friend refers to the fishes as animals. The other friend argues thatfishes aren’t animals because they don’t have four legs. Which friend is correct? Explain your answer.

How does the structure of vertebrates help them to function?

Greek Word Origins

Greek Word Meaning of Greek Word Key Term

amphibios living a double lifeamphibian An animal that spends part of its life cycle on land and part in water

Greek Word Meaning of Greek Word Key Term

chordé string, cordchordate An animal that has a flexible rod that supports the animalís back

Greek Word Origins

Greek Word Meaning of Greek Word Key Term

therme heatendotherm An animal that produces enough heat within its body to control its body temperature

Greek Word Origins

Apply It!1. How does the meaning of amphibian relate to the Greek word fromwhich it comes?An animal that lives for part of its life on land and part in water is livinga double life.

2. Can you think of an English word besides chordate that mightcome from the Greek word chordé?Sample: cord

3. In the list of key terms on the next page, find another termbesides endotherm that might come from the Greek wordtherme. Then look up the meaning of the key term and checkhow its meaning relates to the meaning of endotherm.An ectotherm is an animal whose body does not produce much internalheat. An endotherm, in contrast, is an animal whose body does produce internal heat to maintain its temperature.

Section 12.1: What Is a Vertebrate?

What are the characteristics of chordates and vertebrates?How have scientists been able to infer the relationships of major groups of vertebrates?How do vertebrates differ in the way they control body temperature?

Ancient Jawless FishLook backward in time, into an ocean 530 million years ago. There you see a strange-looking creature—a jawless fish—that is about as long as your index finger.

What is a Chordate?All chordates have 4 basic features that are present at some point during their life cycle

Hollow Nerve Cord – Nerve cord in which nerves branch out at regular intervalsNotochord – Long supporting rod that runs throughout bodyPharyngeal Pouches – Paired structures in throatMuscular Tail – Extends beyond anus

Only 4-5% of animals are chordatesExamples = Fish, Amphibians, Reptiles, Birds

Characteristics of ChordatesThis lancelet shows the characteristics of a chordate: a notochord, a nerve cord down its back, and gill slits.

Evolution of VertebratesThe pattern of vertebrate evolution is branching.

Section 30-1

Nonvertebratechordates

FishesAmphibians

ReptilesBirds

Mammals

Invertebrate ancestor

Chordate Cladogram

End of Section12.1: What Is a Vertebrate?

Section 2: Fishes

What are the characteristics of chordates and vertebrates?How have scientists been able to infer the relationships of major groups of vertebrates?How do vertebrates differ in the way they control body temperature?

FishThey breathe with gills.They are cold blooded.Their skin is covered with scales and bony plates.They lay eggs and have live births.An example of a fish is a gold fish and sharks.

Characteristics of FishesMost fishes obtain oxygen through gills. Water flows into the mouth of the fish and then over its gills. Oxygen moves into the blood and is delivered to the cells of the fish.

Groups of Fish

Jawless Fish – Have mouths of soft tissue with no true teeth.Have no bonesOnly vertebrates with no vertebral column as adultsLampreys, Hagfish

CARTILAGINOUS FISH

Chondrichthyes – Skeleton built entirely of cartilageSharks, sea rays

BONY FISHOsteichthyes –

Majority of fish fall in this orderCarp, sea horse, perch, etc.

Bony FishesA bony fish has jaws, scales, a pocket on each side of the head that holds the gills, and a skeleton made of hard bones.

Section 3: Amphibians

What is the life cycle of an amphibian?How are adult amphibians adapted to living on land?

AmphibiansThey breathe with lungs and gills.They are cold blooded.Their skin is smooth and moist.Their birth of young is eggs.The examples are frogs, salamanders, newt, and mud puppies.

What Is an Amphibian?During its metamorphosis from tadpole to adult, a frog’s body changes dramatically.

Living on LandMany adult amphibians have lungs, a heart with three chambers, and a double-loop circulatory system.

that allow for

are

that providethat allow

are

and have special adaptations such as

larvæ they live in adults they live on

Section 30-3

means

as

Efficientmovement

Breathingair

Support andprotection

Bones Lungs Ribs

Amphibians

Water Land

“Double life”

Groups of AmphibiansSalamanders –

Long bodies and tailsAdults are carnivorousUsually live in moist woods

Spotted Salamander

Frogs and Toads –

Lack tailsFrogs have long legs and are usually tied to waterToads have shorter legs and not as closely tied to water

Poison Dart FrogFire Bellied Toad

Caecilians –

Legless animals that burrow in moist soilHave fishlike scales

Section 4: Reptiles

What adaptations allow reptiles to live on land?What are the characteristics of each of the three main groups of reptiles?What environmental change may have caused the extinction of the dinosaurs?

Reptiles

They breath with lungs.They are cold-blooded.There bodies are covered with dry scales.They lay eggs.Black snakes, Bearded dragons, Turtles, Crocodiles, and Alligators are reptiles.

Adaptations for Life on LandThe membranes and shell of an amniotic egg protect the developing embryo.

Groups of ReptilesLizards and Snakes

Have legs & clawed toes (lizards) external ears, moveable eyelidsHighly evolved specialized forms (venom)

Coral Snake

Nile Crocodile North American Alligator

Long, typically broad snout and squat appearanceAll are carnivorousProtective of young; carry hatchlings in their mouthLive in tropics and subtropicsAlligators live in freshwaterCrocodiles live in fresh or saltwater

Crocodiles and Alligators

Sea TurtleGalapagos Tortoise

Tuatara

Turtles and Tortoises –All are shelledTurtles are aquatic; tortoises are terrestrial

Tuatara – Primitive reptiles found on small, remote islands

Groups of Reptiles (con.)

The Sex Ratio of Newly Hatched Alligators

The temperature of the developing eggs of the American alligator affects the sex ratio of the young. (Sex ratio is the number of females compared with the number of males.)

The Sex Ratio of Newly Hatched Alligators

29.4ºC

Reading Graphs:

At which temperature(s) did only females hatch?

The Sex Ratio of Newly Hatched Alligators

The warmer the incubation temperature, the greater the proportion of males.

Drawing Conclusions:

What effect does the temperature of developing eggs have on the sex of the baby alligators?

The Sex Ratio of Newly Hatched Alligators

According to the graph, out of the 50 alligators that were incubated at 31.7ºC, about 40 (or 80%) were males. So 80% of 100 eggs (80) could be expected to hatch as males.

Calculating:

If 100 eggs developed at 31.7ºC, about how many of the young would be male?

Extinct Reptiles–The DinosaursClimate change may have caused the extinction of dinosaurs and other organisms.

Section 5: Birds

What are the main characteristics of birds?

BirdsBirds breathe with lungs.They are warm-blooded.They are covered with feathers.They give birth to eggs.Examples of birds would be a red bird, hawk, and chicken.Some unusual birds are the ostrich, flamingo, and penguin.

Characteristics of BirdsThe bodies of most birds have adaptations for flight.

Section 31-2

which are that also that power that provide that ensure

have the followingadaptations to flight

Birds

Homologous tofront limbs in other

vertebrates

Providewarmth

Upward anddownward wing

strokes

One-way flowof O2-rich air

O2 distributionto body tissues

Wings Feathers Strong chestmuscles

Efficientrespiratory

system

Efficientcirculatory

system

Characteristics of BirdsAir sacs and a four-chambered heart help birds obtain oxygen and move it to their cells.

Characteristics of BirdsBirds have four-chambered hearts and double-loop circulatory systems that efficiently move oxygen to their cells.

Characteristics of BirdsSome birds like this hawk have a crop and a gizzard. The crop stores food, and the gizzard crushes food.

Groups of BirdsMore than thirty orders of birdsSome of the most common

Perching Birds – largest order; many are songbirds (sparrows, crows, cardinals, etc.)

Purple Finch

Birds of Prey– fierce predators with hooked bills; large talons (condors, hawks, owls, eagles, etc.)

Red-Tailed Hawk

Eagle

Herons & Relatives– Wade in aquatic habitats (storks, herons, cranes)

Stork Heron

Ostriches & Relatives– flightless birds move by running or swimming (ostriches, emus, etc.)

Emu

End of Section: Birds

Section 6: Mammals

What characteristics do all mammals share?What are the main groups of mammals and how do they differ in their reproduction?

MammalsMammals breathe with lungs.They are warm blooded.They have hair/fur.Most give birth to live young.Some examples are bears, lions, tigers, and people.Some unusual examples bats, whales, and dolphins

Diversity of MammalsThe three main groups of mammals are monotremes, marsupials, and placental mammals.

kangaroo spiny anteater giraffe

Orders of Placental Mammals

OrderInsectivores

SireniansCetaceans

Chiropterans Rodents

Section 32-2

Characteristics Examples

Long, narrow snouts, sharp claws

Water-dwelling, slow-moving

Live and breed in ocean, come to surface to breathe

Winged, capable of true flight

Single pair of long, curved incisor teeth in upper and lower jaws

Shrews, hedgehogs, moles

Manatees, dugongs

Whales, dolphins

Bats

Mice, rats, voles, squirrels, beavers, porcupines, chinchillas

Orders of Placental Mammals

OrderPerissodactyls

Carnivores

Artiodactyls

Proboscideans

Characteristics Examples

Section 32-2

Hoofed, with an odd number of toes on each foot

Sharp teeth and claws

Hoofed, with an even number of toes on each foot

Trunks

Horses, tapirs, rhinoceroses, zebras

Tigers, hyenas, dogs, foxes, bears, raccoons, walruses

Cattle, sheep, goats, pigs, ibex, giraffes, hippopotami, camels

Asian and African elephants, mastodons and mammoths

Orders of Placental Mammals

OrderLagomorphs

Xenarthrans

Primates

Characteristics Examples

Section 32-2

Two pairs of incisors in upper jaw, hind legs allow leaping

No teeth (or very small teeth in the back of the jaw)

Highly developed cerebrum and complex behaviors

Snowshoe hares, rabbits

Sloths, anteaters, armadillos

Lemurs, tarsiers, apes, gibbons, macaques, humans

Mammal Diversity

This circle graph shows the percentage of species of some types of mammals.

Mammal Diversity

21.8 %

Reading Graphs:

What percentage of species are bats?

Mammal Diversity

78.2 %

Calculating:

What percentage of species are not bats?

Mammal Diversity

The group with the greatest number of species, rodents, would be the tallest.

Graphing:

Suppose you used the data shown in the circle graph to make a bar graph. Which bar would be tallest?

Mammal Diversity

100; no, you do not have to add them because it is a circle chart—the entire chart stands for 100 percent of the items counted— in this case, mammal species.

Predicting:

What total should all the percentages in the pie chart add up to? Do you have to add the percentages to obtain your answer? Explain

End of Section: Mammals