Table of Contents
Chapter
Preview
12.1 Structure
and Function of Vertebrates
12.1
12.2 What
FishesIs a Vertebrate?
12.2 Fishes
12.3 Amphibians
12.3 Amphibians
12.4 Reptiles
12.4 Reptiles
12.5 Birds
12.5 Birds
12.6 Mammals
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 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 Questions
2.
The major cause of extinction of species is
a. 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 is
a. 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 reproduce
a. sexually only.
b. asexually only.
c. with alternating sexual and
asexual stages.
d. by binary fission.
Chapter 12 Preview Questions
4. Most animals reproduce
a. sexually only.
b. asexually only.
c. with alternating sexual and asexual stages.
d. by binary fission.
How does the structure of vertebrates help them
to function?
Two friends are looking at fishes in an
aquarium. One friend refers to the fishes
as animals. The other friend argues that
fishes aren’t animals because they don’t
have four legs. Which friend is correct?
Explain your answer.
Greek Word Origins
Greek Word
amphibios
Meaning of Greek Word
Key Term
living a double life
amphibian An animal that
spends part of its life cycle
on land and part in water
Greek Word Origins
Greek Word
chordé
Meaning of Greek Word
Key Term
string, cord
chordate An animal that
has a flexible rod that
supports the animalís back
Greek Word Origins
Greek Word
therme
Meaning of Greek Word
heat
Key Term
endotherm An animal that
produces enough heat
within its body to control its
body temperature
Apply It!
1. How does the meaning of amphibian relate to the Greek word from
which it comes?
An animal that lives for part of its life on land and part in water is living
a double life.
2. Can you think of an English word besides chordate that might
come from the Greek word chordé?
Sample: cord
3. In the list of key terms on the next page, find another term
besides endotherm that might come from the Greek word
therme. Then look up the meaning of the key term and check
how its meaning relates to the meaning of endotherm.
An ectotherm is an animal whose body does not produce much internal
heat. 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 Fish
Look 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 intervals
Notochord – Long supporting rod that runs throughout body
Pharyngeal Pouches – Paired structures in throat
Muscular Tail – Extends beyond anus
Only 4-5% of animals are chordates
Examples = Fish, Amphibians, Reptiles, Birds
Characteristics of Chordates
This lancelet shows the characteristics of a chordate: a
notochord, a nerve cord down its back, and gill slits.
Evolution of Vertebrates
The pattern of vertebrate evolution is branching.
Chordate Cladogram
Section 30-1
Mammals
Birds
Amphibians
Fishes
Nonvertebrate
chordates
Invertebrate ancestor
Reptiles
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?
Fish
They 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 Fishes
Most 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 bones
Only vertebrates with no vertebral
column as adults
Lampreys, Hagfish
CARTILAGINOUS FISH
Chondrichthyes –
Skeleton built entirely of cartilage
Sharks, sea rays
BONY FISH
Osteichthyes –
Majority of fish fall in this order
Carp, sea horse, perch, etc.
Bony Fishes
A 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?
Amphibians
They 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 Land
Many adult amphibians have lungs, a
heart with three chambers, and a
double-loop circulatory system.
Section 30-3
Amphibians
means
“Double life”
as
larvæ they live in
adults they live on
Water
Land
and have special adaptations such as
Bones
that allow for
Efficient
movement
Lungs are
Ribs
that allow
that provide
Breathing
are
air
Support and
protection
Groups of Amphibians
Salamanders –
Long bodies and tails
Adults are carnivorous
Usually live in moist woods
Spotted Salamander
Frogs and Toads –
Lack tails
Frogs have long legs and are usually tied to
water
Toads have shorter legs and not as closely
tied to water
Fire Bellied Toad
Poison Dart Frog
Caecilians –
Legless animals that burrow in moist soil
Have 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 Land
The membranes and shell of an amniotic egg protect the
developing embryo.
Groups of Reptiles
Lizards and Snakes
Have legs & clawed toes (lizards) external
ears, moveable eyelids
Highly evolved specialized forms (venom)
Coral Snake
Crocodiles and Alligators
Long, typically broad snout and squat appearance
All are carnivorous
Protective of young; carry hatchlings in their mouth
Live in tropics and subtropics
Alligators live in freshwater
Crocodiles live in fresh or saltwater
Nile Crocodile
North American Alligator
Groups of Reptiles (con.)
Turtles and Tortoises –
All are shelled
Turtles are aquatic; tortoises are terrestrial
Tuatara –
Primitive reptiles found on small, remote islands
Galapagos Tortoise
Sea Turtle
Tuatara
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
Reading Graphs:
At which temperature(s) did
only females hatch?
29.4ºC
The Sex Ratio of Newly Hatched Alligators
Drawing Conclusions:
What effect does the
temperature of developing
eggs have on the sex of the
baby alligators?
The warmer the incubation
temperature, the greater the
proportion of males.
The Sex Ratio of Newly Hatched Alligators
Calculating:
If 100 eggs developed at
31.7ºC, about how many of
the young would be male?
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.
Extinct Reptiles–The Dinosaurs
Climate change may have caused the
extinction of dinosaurs and other
organisms.
Section 5: Birds
What are the main characteristics of birds?
Birds
Birds 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 Birds
The bodies of most birds have adaptations for flight.
Section 31-2
Birds
have the following
adaptations to flight
Wings
Feathers
Strong chest
muscles
Efficient
respiratory
system
Efficient
circulatory
system
which are
that also
that power
that provide
that ensure
Homologous to
front limbs in other
vertebrates
Provide
warmth
Upward and
downward wing
strokes
One-way flow
of O2-rich air
O2 distribution
to body tissues
Characteristics of Birds
Air sacs and a four-chambered heart help birds obtain
oxygen and move it to their cells.
Characteristics of Birds
Birds have four-chambered hearts and
double-loop circulatory systems that efficiently
move oxygen to their cells.
Characteristics of Birds
Some birds like this hawk have a crop and a gizzard. The
crop stores food, and the gizzard crushes food.
Groups of Birds
More than thirty orders of birds
Some 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?
Mammals
Mammals 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 Mammals
The three main groups of mammals are monotremes,
marsupials, and placental mammals.
kangaroo
spiny anteater
giraffe
Section 32-2
Orders of Placental Mammals
Order
Characteristics
Examples
Insectivores
Long, narrow snouts, sharp
claws
Shrews, hedgehogs, moles
Sirenians
Water-dwelling, slow-moving
Manatees, dugongs
Cetaceans
Live and breed in ocean, come
to surface to breathe
Whales, dolphins
Chiropterans
Winged, capable of true flight
Bats
Rodents
Single pair of long, curved incisor
teeth in upper and lower jaws
Mice, rats, voles, squirrels,
beavers, porcupines, chinchillas
Section 32-2
Orders of Placental Mammals
Order
Characteristics
Examples
Perissodactyls Hoofed, with an odd number of
toes on each foot
Horses, tapirs, rhinoceroses,
zebras
Carnivores
Sharp teeth and claws
Tigers, hyenas, dogs, foxes, bears,
raccoons, walruses
Artiodactyls
Hoofed, with an even number of
toes on each foot
Cattle, sheep, goats, pigs, ibex,
giraffes, hippopotami, camels
Proboscideans Trunks
Asian and African elephants,
mastodons and mammoths
Section 32-2
Orders of Placental Mammals
Order
Characteristics
Examples
Lagomorphs
Two pairs of incisors in upper
jaw, hind legs allow leaping
Snowshoe hares, rabbits
Xenarthrans
No teeth (or very small teeth in
the back of the jaw)
Sloths, anteaters, armadillos
Primates
Highly developed cerebrum and
complex behaviors
Lemurs, tarsiers, apes, gibbons,
macaques, humans
Mammal Diversity
This circle graph shows the
percentage of species of
some types of mammals.
Mammal Diversity
Reading Graphs:
What percentage of species
are bats?
21.8 %
Mammal Diversity
Calculating:
What percentage of species
are not bats?
78.2 %
Mammal Diversity
Graphing:
Suppose you used the data
shown in the circle graph to
make a bar graph. Which bar
would be tallest?
The group with the greatest
number of species, rodents,
would be the tallest.
Mammal Diversity
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
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.
End of Section:
Mammals