chapter 12 what is a vertebrate? 12.1 structure and function of vertebrates 12.2 fishes 12.3...

Chapter 12 What Is a Vertebrate?

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 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.



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.



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.



4. Most animals reproduce

a. 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 that

fishes 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



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

Greek Word Origins



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.


End of Chapter Preview


Section 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.


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.


Links on Vertebrates

Click the SciLinks button for links on vertebrates.


Vertebrates

Click the Video button to watch a movie about vertebrates.


End of Section: 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?


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.


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.


End of Section: Fishes


Section 3: Amphibians

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


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.


Respiration and Circulation Activity

Click the Active Art button to open a browser window and access Active Art about respiration and circulation.


More on The Frog Life Cycle

Click the PHSchool.com button for an activity aboutthe frog life cycle.


End of Section: Amphibians


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?


Adaptations for Life on Land

The membranes and shell of an amniotic egg protect the developing embryo.


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.)



29.4ºC

Reading Graphs:

At which temperature(s) did only females hatch?



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?



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 Dinosaurs

Climate change may have caused the extinction of dinosaurs and other organisms.


More on Reptiles

Click the PHSchool.com button for an activity about reptiles.


Interpreting Fossils

Click the Video button to watch a movie aboutinterpreting fossils.


End of Section: Reptiles


Section 5: Birds

What are the main characteristics of birds?


Characteristics of Birds

The bodies of most birds have adaptations for flight.



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



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


Respiration and Circulation Activity

Click the Active Art button to open a browser window and access Active Art about respiration and circulation.



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


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?


Diversity of Mammals

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

kangaroo spiny anteater giraffe


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


Links on Mammals

Click the SciLinks button for links on mammals.


End of Section: Mammals


QuickTake Quiz

Click to start quiz.

chapter 12 what is a vertebrate? 12.1 structure and function of vertebrates 12.2 fishes 12.3...

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chapter preview questions

water slide

permian extinction

mass extinction

major cause of extinction

fishes arent animals

english word

specific function