Focus on California Life Science 7th Grade Unit 3 - Chapter 12 Structure and Function of Vertebrates

Invertebrates on Branches . Problem How can you construct a branching tree diagram to classify some Wings invertebrates ?

Skills Focus classifying , interpreting data Exoskeleton Common ancestor Materials index cards Procedure Review the explanation of a branching tree diagram in Chapter . Recall that in a ing tree diagram , the organism with none of the characteristics goes at the bottom of the tree . The organism with the greatest number of derived characteristics goes at the top . Examine the incomplete branching tree diagram . Copy it in your notebook . The table below lists characteristics of five invertebrates . Make a card for each animal that lists the characteristics of that animal . Then arrange the cards in order , beginning with the animal that has none of the and ending with the animal that has all the characteristics . Use the data in the table and your cards to complete the branching tree diagram . Put the missing animals on their correct branches . Identify the missing characteristics . Earthworm . You discover a fossil scorpion similar to the one in the photograph . The fossil animal has an exoskeleton but does not have three body sections . Mark on your copy of the branching tree diagram where the scorpion should go . Analyze and conclude . Classifying Which animal goes at the top of the diagram ?

How many of the listed does the animal have ?

Interpreting Data Except for the earthworm , all the animals in the table belong to the same phylum . To which phylum do these mals belong ?

Drawing Conclusions Which animal in the table is most closely related to the fossil scorpion ?

Explain how you know this . Communicating Which two animals on the diagram are most distantly related ?

Write a paragraph in which you identify the data on which you base your conclusion . More to Explore Do research to learn some of the characteristics that are used to classify insects into groups . Write a report about what you have learned . Characteristics of Some Invertebrates Butterfly

Section Students know the between the cycles and reproduction methods of sexual and asexual organisms . Students know organ function because of the of individual organs , tissues , and cells . The failure of any part can affect the entire system . What are the main characteristics ' of What are the major groups of ?

Key Terms echinoderm endoskeleton water vascular system tube feet I . How Do Sea Stars Hold On ?

Use a plastic dropper and water to model how a sea star moves and clings to surfaces . Fill the dropper with water , and then squeeze out most of the water . Squeeze the last drop of water onto the inside of your arm . Then , while squeezing the bulb , touch the tip of the dropper into the water drop . With the dropper tip against your skin , release the bulb . Hold the dropper by the tube and lift it slowly , paying attention to what happens to your skin . Think it Over Predicting Besides moving and clinging to surfaces , what might sea stars use their suction structures for ?

While exploring a rocky beach one day , you see what looks like a dill pickle at the bottom of a tide pool . You think it might be a plant or a rock covered with green slime . But as you look more closely , the pickle begins to crawl very slowly . This ing creature is a sea cucumber , a relative of sea stars . Characteristics of Sea cucumbers , sea stars , sea urchins , and sand dollars are all ( ee KY noh ) members of the phylum . are invertebrates with an internal skeleton and a system of tubes called a water vascular system . All live in salt water . Body Structure The skin of most is stretched over an internal skeleton , or endoskeleton , made of hardened plates . These plates support the animal and give it a bumpy texture . Adult have a unique kind of radial in which the body parts , usually in multiples of , are arranged like spokes on a wheel . Chapter 11

Go for Water Vascular System activity Visit Web Code mun so A Water Vascular System , such as this sea star , have a water vascular system that helps them move and catch food . Interpreting Diagrams Where does water enter the water vascular system water Vascular System The sea star water vascular system extends into each one of its arms . Movement The internal organ system of tubes in is called the water vascular system . You can see a sea star water vascular system in Figure 30 . Portions of the tubes in this system can contract , or squeeze together , forcing water into structures called tube feet . This process is something like moving water around in a water balloon by squeezing ferent parts of the balloon . The ends of tube feet are sticky . When with water . they act like small , sticky suction cups . The stickiness and tion enable the tube feet to grip the surface beneath the . Most use their tube feet to move along slowly and to capture food . Reproduction and Life Cycle Almost all are either male or female . Eggs are usually fertilized in the water , after a female releases her eggs and a male releases his sperm . The fertilized eggs develop into tiny , swimming larvae that look very different from the adults . The larvae eventually undergo metamorphosis and become adult . Reading What are the functions of an tube feet ?

Tube Feet tube feet line the underside of a sea star arms and act like tiny suction cups . In a sea star . water enters . the water vascular system partly through an opening in this round plate .

Diversity of There are four major groups of sea stars , sea urchin brittle stars , sea urchins , and sea cucumbers . The members of these groups look quite different . They also have different ways of feeding and moving . Sea stars are predators that eat mollusks , crabs , and even other . Sea stars use their tube feet to move across the ocean floor . They also use their tube feet to capture prey . A sea star will grasp a clam with all arms , and then pull the shells open . Then the sea star feeds on the clam tissues . A brittle star arms are long and slender . To move , a brittle star waves its arms in a snakelike motion against the ocean floor . A brittle star uses its tube feet to catch food . sea Cucumber Sea urchins have no arms . Spines cover and protect their mu bodies , so they look something like a pincushion . To move , sea Diversity of urchins use tube feet that extend out between the spines . They scrape and cut food with five toothlike structures . are diverse in their Sea cucumbers look a little bit like the cucumbers you eat . appearance but all have With tube feet on their underside . sea cucumbers crawl along symmetry and are found in the ocean . They feed with a mouth surrounded by tentacles . the I . Writing . Section Assessment Vocabulary Skill Use Clues to Determine Meaning A Look at the of endoskeleton on page 443 . What writing I Ce . phrase in the sentence gives the meaning of endoskeleton ?

comparison In a Reviewing Key Concepts comp . and a . Reviewing What characteristics do have ?

how , ma Summarizing Explain how reproduce . Inferring In , could fertilization take place without water ?

Why or why not ?

Identifying Identify the four major groups of . Comparing and Contrasting Compare and contrast how sea stars and sea urchins feed . Predicting Would a sea star be able to eat clams without using its tube feet ?

Explain . Chapter 11 445 Chapter 11 Study Guide TI 19 I a The structures of animals bodies enable them to obtain food and oxygen , keep internal conditions stable , move , and reproduce . what Is an Animal ?

Key Concepts The cells of most animals are organized into tissues , organs , and organ systems . Some major functions of animals are obtaining food and oxygen , keeping internal conditions stable . moving , and reproducing . Symmetry is a balanced arrangement of body parts that is characteristic of many animals . Animals are according to how they are related to other animals . Key Terms anatomy physiology bilateral symmetry radial symmetry invertebrate phylum Sponges and Key Concepts . Sponges are invertebrates that usually lack symmetry and never have tissues or organs . use stinging cells to capture food and defend themselves . Key Terms larva cnidarian polyp medusa Worms and Mollusks Key Concepts , All worms are invertebrates that have long , narrow bodies without legs . Unlike or flatworms , have a digestive system that is like a tube , open at both ends . Segmented worms have bodies made up of many linked sections called segments . In addition to a soft body often covered by a shell , a mollusk has a mantle and a foot . The three major groups of mollusks are . bivalves . and cephalopods . 4460 Key Terms brain parasite host anus closed circulatory system mollusk open circulatory system gill gastropod radula bivalve cephalopod Arthropods Key Concepts . Arthropods are invertebrates that have an external skeleton , a segmented body , and jointed attachments called appendages . The major groups of arthropods are crustaceans , arachnids , centipedes and millipedes , and insects . A crustacean is an arthropod that has two or three body sections , or more pairs of legs , and two pairs of antennae . Arachnids are arthropods with two body sections , four pairs of legs , and no antennae . insects have three body sections , six legs , one pair of antennae , and usually one or two pairs of wings . Each insect species undergoes either complete metamorphosis or gradual metamorphosis . Key Terms arthropod exoskeleton molting antenna crustacean metamorphosis arachnid abdomen insect thorax complete metamorphosis pupa gradual metamorphosis nymph Key Concepts , are invertebrates with an internal skeleton and a system of tubes called a water vascular system . Groups of include sea stars , brittle stars , sea urchins , and sea cucumbers . Key Terms echinoderm water vascular system tube feet

Go For Visit Web Code Review and Assessment Target Reading Skill Take Notes To review part Section , take notes on the text following the heading Movement . Copy the incomplete graphic organizer shown on the right . Complete it by answering the questions . Reviewing Key Terms Choose the letter of the best answer . An animal without a backbone is called a ( Complete the following sentences so that your answers clearly explain the key terms . vertebrate . A sea anemone is a described as a polyp invertebrate . because its body is . larva . Unlike the blood in an open circulatory system , the blood in a closed circulatory . Which group of animals uses stinging cells to system ' A gastropod has a radula . which is vertebrates a ( mans 10 . An insect body is protected by its ( Sponges exoskeleton which is a ( Which organ do most mollusks and crustaceans use to obtain oxygen ?

11 . Unlike gradual metamorphosis , complete metamorphosis has radula lungs gills Writing in Science . An arthropod antennae are located on its ' head are covering a ' a ' has washed up on the local beach . Writes short news story describing the discovery . At which stage of insect development do major changes in body structure occur ?

an . egg larva haul Saul . move by using structures called . Arthropods . wings . appendages . tube feet . abdomens . sure to describe how scientists the animal as a squid . Chapter 11 441 Review and Assessment Checking Concepts 12 . Explain the relationship among cells , tissues , and organs . 13 . What are five key functions of animals ?

14 . Explain what a digestive system is . 15 . Describe the structure of a mollusk gills . 16 . Contrast the functions of an compound eyes and simple eyes . 17 . What is an endoskeleton ?

What is its function ?

Thinking Critically 18 . Making Judgments Suppose a book is called Earth Animals . All the animals in the book are vertebrates . Is this title a good one ?

Explain your reasoning . 19 . Classifying Classify each of the following animals as having radial symmetry , bilateral symmetry , or no symmetry sea anemones . sponges , fishes , humans . and . 20 . Classifying Which of the animals below is a roundworm ?

A sponge ?

A cnidarian ?

Describe the major characteristics shared by members of each phylum . It 21 . Comparing and Contrasting Compare and contrast bivalves and cephalopods . 22 . Applying Concepts Explain why the development of a lion , which grows larger as it changes from a tiny cub to a adult , is not metamorphosis . 23 . Applying Concepts Some seafood restaurants serve a dish called crab . What do you think happened to the crab just before it was caught ?

Why is this process important ?

4480 24 . Classifying Your friend said he found a dead insect that had two pairs of antennae and eight legs . this possible ?

Why or why not ?

25 . Comparing and Contrasting Compare and contrast centipedes and millipedes . Applying Skills Use the data table to answer Questions . The following data appeared in a book on insects . Flight Characteristics moth Bumblebee Housefly 26 . Graphing Use the data to make two bar graphs one showing the three insect rates and another showing the speeds 27 . Interpreting Data Which of the three insects has the highest rate ?

Which insect the fastest ?

28 . Drawing Conclusions Based on the data , is there a relationship between the rate at which an insect beats its wings and the speed at which it ?

Explain . What factors besides rate might affect flight speed ?

Standards Investigation Performance Assessment Prepare a display to show how you set up your experiment and what your results were . Construct and display graphs to show the data you collected . Include pictures of the mealworms in each stage of development . Write your conclusion of how the experimental conditions affected the growth and development of the mealworms . Also suggest some possible explanations for your results .

Standards Practice Choose the letter of the best answer . What is the correct sequence in which a stinging cell reacts to the touch of another organism ?

A trigger brushes against prey , stinging cell , barbs snare prey barbs snare prey , stinging cell , barbs release prey prey is paralyzed . venom enters prey . stinging cell tentacles pull prey to mouth , prey is ingested , stinging cell fires . Which of the following is true of a digestive system ?

A It is found in all parasites . It has two openings . It has one opening . It is found in all parasites and has one opening . Use the diagram below and your knowledge of science to answer Question . Of the four animals above , which have sense organs concentrated at one end of their bodies ?

A animals A and animals A , and animals and animals A . and at . Which of the following statements is true about gradual metamorphosis ?

A Gradual metamorphosis is a life cycle that involves asexual reproduction . In gradual metamorphosis , a larva develops into a pupa . In gradual metamorphosis , an egg hatches into a nymph . Gradual metamorphosis has four distinct stages . Use the diagram below and your knowledge of science to answer Question . You are constructing a branching tree diagram that shows the relationship between animals A and above . Which of the following characteristics could you use to place the two animals on different branches ?

A type of circulatory system presence or absence of jointed appendages type of digestive system presence or absence of antennae . Which of the following best describes the stages in the sexual life cycle of a sponge in the correct order ?

A larva , fertilization , egg and sperm , adult adult , larva , egg and sperm , fertilization adult , bud , bud breaks free egg and sperm , fertilization , larva , adult . Explain how a sea star water vascular system enables the sea star to move . Chapter 11 us

. Chapter 12 Preview A typical cell of any organism contains genetic instructions that fy its traits . Those traits may be fied by environmental influences . As a basis for understanding this concept a . Students know the differences between the life cycles and duction method of sexual and ual organisms Biological evolution accounts for the diversity of species developed through gradual processes over many generations . As a basis for ing this concept . Students know that of species occurs when the ment and the adaptive characteristics of a species are for survival Evidence from rocks allows us to understand the evolution of life on Earth . As a basis for understanding this concept . Students know how to explain developments and lions of plant and animal life on he geologic time scale . The anatomy and physiology of plants and animals illustrate the mentary nature of structure and tion . As a basis for this concept . Students know plants and animals have levels of ( lOn for ture and function , including cells , tissues . organs , organ systems , and the whole organism . Students know organ systems tion because of the contributions of organs . tissues , and cells . The failure of any part can affect the entire system Like all . the in this school of are vertebrates . 450 Structure and Function of Vertebrates

, Preview . School Birds and Mammals ?

Focus on the A BIG Ideas . How does the structure of vertebrates help them to function ?

Check What You Know Two friends are looking at fishes in an aquarium . One friend refers to the fishes as animals . The other friend argues that fishes are animals because they do have four legs . Which friend is correct ?

Explain your answer . Chapter 12 451 The images shown here represent some of the key terms in this chapter . You can use this vocabulary skill to help you understand the meaning of some key terms in this chapter . Some key terms in this chapter contain word parts whose origins are Greek . The table below lists some of the Greek words that key terms come from . Learning the meanings of these Greek words will help you understand and remember some key terms . I Greek Word Origins amphibian An animal that spends part of its life cycle on land and part in water heat An animal that produces enough heat within its body to control its body temperature Apply It ! How does the meaning of amphibian relate to the Greek word from which it comes ?

can you think of an English word besides chordate that might come from the Greek word ?

In the list of key terms on the next page . find another term besides that might come from the Greek word . Then look up the meaning of and check .

i Chapter 12 Vocabulary Section ( page 456 ) notochord Section ( page 462 fish cartilage swim bladder Section ( page 468 amphibian atrium tadpole ventricle habitat Section page ) reptile contour feather ( egg kidney urine amniotic egg Section ( page ) bird contour feather down feather Section 486 ' mammal mammary gland ' diaphragm monotreme marsupial gestation period mammal placenta Build Science Vocabulary Online Visit Web Code Chapter 12 453

to Be . El Coding Skill Compare and Contrast when you compare and contrast , you examine similarities and differences between things . You can do this by using a table . Follow these steps to set up a table . a List the characteristics to be compared across the top . List the items to be compared in the left column . Complete the table by filling in information about each characteristic . Vertebrates can be divided into two and on how their body temperatures are controlled . Study the table and then answer the questions . Type of Body Characteristics of Body Groups With This Type Temperature Control at Temperature Control Control Body temperature changes , Fishes , amphibians , depending on the temperature reptiles of the environment . Body temperature stays about Birds , mammals the same , no matter what the temperature of the environment . Apply It ! Which vertebrate groups are ?

Which type of or a body temperature that is more affected by the temperature of the environment ?

As you read , construct tables . For Section , compare the characteristics of jawless fishes , cartilaginous fishes , and bony fishes . For Section , compare the reproduction of , marsupials , and placental mammals .

I Standards Investigation . Animal Adaptations How does an animal capture food , escape from predators , or obtain oxygen ?

To help answer these questions , you will create models of three different animals and show how each is adapted to its environment . Your Goal To make models of a fish , an amphibian , and a reptile that show how each is adapted to carry out one life function in its environment To complete this investigation , you must select one life function to show I build a model of each type of animal , showing the adaptations each has for carrying out the function you selected make a poster that explains how each animal adaptation is suited to its environment follow the safety guidelines in Appendix A Plan It ! Pair up with a classmate and share what you already know about fishes , amphibians , and reptiles . Answer the following questions Where do these animals live ?

How do they move around ?

How do they protect themselves ?

Decide on the life function you will show . As you read about these types of animals , make your models showing the adaptations the animals have for carrying out the functions . Chapter 12 455 CALIFORNIA Standards Focus Students know how to explain significant developments and extinctions of plant and animal life on the geologic time scale . Students know how bones and muscles work together to a structural framework for movement . What are the characteristics of 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 ?

Key Terms chordate notochord vertebra 4560 Ancient jawless fish What Is a Vertebrate ?

How Is an Umbrella Like a Skeleton ?

Open an umbrella . Turn it upside down and examine how it is made . Now close the umbrella and watch how the braces and ribs collapse . Think of what would happen if you removed the ribs from the umbrella and then tried to use it during a rainstorm . Think it Over Inferring What is the function of the ribs of an umbrella ?

How are the ribs of the umbrella similar to the bones in your skeleton ?

How are they different ?

Look backward in time , into an ocean 530 million years ago . There you see a jawless is about as long as your index . The creature is swimming with a motion , like a flag in the wind . Its tail fin is broad and . Tiny plates cover its small body . Its eyes are set wide apart . If you could see inside the mal , you would notice that it has a backbone . You are looking at one of the earliest vertebrates , at home in an ancient sea . Characteristics of Vertebrates like the ancient jawless fish are a subgroup in the phylum Chordata . All members of this phylum are called ( At some point in their lives , all have three characteristics a notochord , a nerve cord that runs down their back , and slits in their throat area . Most , including , amphibians , and reptiles , are vertebrates . So are birds and mammals . But a few , such as , are invertebrates . Notochord The phylum name Chordata comes from the notochord , a rod that supports a chordate back . Some , like the lancelet shown in Figure , have chords all their lives . In contrast , in vertebrates , part or all of the notochord is replaced by a backbone .

Nerve Cord in Back In addition to having a notochord , all have a nerve cord that runs down their back Your spinal cord is such a nerve cord . The nerve cord is the tion between the brain and the nerves , on which messages travel back and forth . Many other groups of pods and segmented , for nerve cords , but their nerve cords do not run down their backs . In Throat Area At some point in their lives , have slits in their throat area called pharyngeal ( RIN jee til ) slits , or gill slits . Some , including , keep these slits as part of their gills for their entire lives . But in many vertebrates , including humans , pharyngeal slits disappear before birth . What is a notochord ! Characteristics of Vertebrates Vertebrates have the characteristics shared by all . In addition , vertebrates share certain other characteristics . A vertebrate has a backbone that is pan of an internal skeleton . This internal skeleton , or endoskeleton , supports the body and allows it to move . Backbone You can see in Figure that a vertebrate backbone , which is also called a spine , runs down the center of its back . The backbone is formed by many similar bones called vertebrae ( singular vertebra ) The vertebrae are lined up in a row like beads on a string . or movable connections between the vertebrae , give the spine . You can bend over and tie your shoes because your backbone has . Each bra has a hole in it that allows the spinal cord to pass through it . The spinal cord into the vertebrae like fit into rings . FIGURE Characteristics of a Lancelet This lancelet shows the characteristics of a chordate a notochord that helps support its body , a nerve cord down its back , and gill slits . the Backbone of a Lizard The backbone of this gila monster has flexibility . Predicting Could the backbone bend if it did not have joints ?

Chapter 12 457 FIGURE The Skeleton of a Seal This seal skeleton has adaptations for swimming . Long , flat bones support the flippers . The skull helps the seal move smoothly through the water . Go CA ?

For Links on Web Code ) 231 Internal Skeleton The backbone of a vertebrate is part of its endoskeleton . In addition to the backbone , a vertebrate endoskeleton includes the skull and ribs . Many vertebrates also have limb bones adapted for movement . The endoskeleton gives the body shape . It also provides a framework to which muscles can attach . Together , bones and muscles enable a vertebrate body to move . In addition , the endoskeleton protects internal organs . The skull protects the brain . The ribs protect the heart , lungs . and other organs . Unlike an arthropod , a eton grows as the animal grows . Therefore , the endoskeleton does need to be replaced as the animal becomes larger . It also forms an internal frame that supports the body against the downward pull of gravity , while allowing easy movement . Because of their , vertebrates can grow bigger than animals with exoskeletons or no skeletons at all . an Evolution of Vertebrates The tiny swam in Earth waters long before vertebrates appeared . Vertebrates probably evolved from an invertebrate chordate ancestor . studying fossils and other evidence , such as DNA , scientists have been able to infer the relationships of the major groups of , amphibians , reptiles , birds , and mammals . shows the probable order of vertebrate evolution . Fossils show that the first vertebrates to live on Earth were probably . Fishes appeared on Earth over 500 million years ago . Amphibians are descended from . Then , amphibians gave rise to reptiles . Both mammals and birds are descended from reptiles . Birds were the latest group of vertebrates to arise . What are two functions of an

Pattern of Vertebrate Evolution FIGURE The pattern of vertebrate evolution is branching . Based on fossils , the first vertebrates , the jawless fishes , arose over 500 million years ago . Interpreting Diagrams Which is the latest group of vertebrates that appeared on Earth ?

First vertebrates Jawless Fishes Millions of Years Ago Keeping Conditions Stable One characteristic that differs among the major groups of is the way they control their body temperature . The body temperature of most , amphibians , and reptiles is close to the temperature of their environment . In contrast , birds and mammals have a stable body temperature that is often warmer than their environment . Fishes , amphibians , and reptiles are . An ( EK toh thurm ) is an animal whose body does not produce much internal heat . An body changes depending on the temperature of its ment For example , when a turtle is lying on a sunny riverbank , it has a higher body temperature than when it is swimming in a cool river . are sometimes called This term is misleading because blood is often quite warm . 12 459

Emperor penguins Temperature Regulation On a cool , sunny morning , a woma python raises its body temperature by basking in the sun . In contrast , an emperor penguin stays warm by producing internal heat . Inferring Which animal is an ?

Vocabulary Skill Greek Word Origins The Greek word means The Greek word means How do these meanings relate to the meanings of and ?

Reviewing Key Concepts a . Listing List three chordate characteristics . Identifying What characteristic do only vertebrates have ?

Relating Cause and Effect How does this characteristic give a body ?

a . Reviewing What evidence indicates relationships among vertebrate groups ?

Interpreting Data Use Figure to determine how many groups of there are . Sequencing Which group appeared last ?

4506 In contrast to a turtle , a beaver would have the same body temperature whether it is in cool water or on warm land . The beaver is an example of an ( EN doh thurm ) animal whose body regulates its own temperature by controlling the internal heat it produces . An body temperature usually does not change much , even when the temperature of its environment changes . Birds and mals , such as beavers , are . also have other adaptations , such as sweat glands and fur or feathers , for maintaining their body . On hot days , some sweat . As the sweat , the animal is cooled . On cool days , fur or feathers keep wann . Because can keep their body temperatures stable , they can live in a greater variety of than can . Reading Summarizing What is the difference between an and an ?

Making Generalizations Would an or an be more active on a cold night ?

Explain your answer . At Home Activity Bumpy Back Rub Have members of your family feel the tops of the vertebrae running down the center of their backs . Then have them feel the hard skull beneath the skin on their foreheads . Tell them about the functions of the backbone and skull .

A Model Backbone . A Problem Analyze and conclude Can you build a functional model of a backbone ?

Making Models As you designed , built , and tested your model backbone , what problems . Skills FOCUS did you encounter ?

How did you solve these making models observing ?

Observing How are the pieces of pasta like vertebrae ?

How are they different ?

20 pieces each of different types of cylindrical Co Write a letter 19 a friend in dried past which you describe how you designed and . 120 of plastic or string built a model backbone . Be sure to explain to your friend what you about procedure backbones by doing this activity . Examine the properties of the materials . Begin by cutting a section of string . an . Write a procedure for an experiment to test the . Choose a shape of pasta that you think would make good vertebrae and thread ti , them onto the string to make a simple model 91 of a backbone . CAUTION Do not eat any of by 01 de ' 59 go the pasta or other food substance in this lab . use De ' teacher has approved your procedure . Bend and twist your backbone model . Can it easily rotate and bend ?

Try to mimic the motions of several different example , a snake , a frog , a horse , or a cat . Using what you learned about the spinal column and the model you just constructed , design and build an improved model bone for an imaginary vertebrate of your choice . Your model should have the ing characteristic The backbone should be made of the materials approved by your teacher . The backbone should be strong enough to protect the spinal cord . The backbone should be highly flexible so that it can easily twist and rotate to match the motions of the vertebrate you chose . As the backbone flexes , the bones should not rub directly together . The backbone should also provide shock absorption for when the vertebrate jumps . 9451

What are the characteristics of most fishes ?

What are the major groups of fishes and how do they Key Terms I fish cartilage swim bladder 4620 Gobies cleaning a A Fishes ' Standards Students know that organ systems function because of the contributions of individual organs , tissues , and cells . The failure of any part can affect the entire system . How Does Water Flow Over a Fish Gills ?

Closely observe a in an aquarium for a few minutes . Note how frequently the fish opens its mouth . Notice the flaps on each side of the head behind its eyes . Observe how the flaps open and close . Observe the movements of the mouth and the flaps at the same time . Note any relationship between the movements of these two structures . Think It Over Observing What do the flaps on the sides of the fish do when the fish opens its mouth ?

What role do you think these two structures play in a fish life ?

In the warm waters of a coral reef , a large spotted fish called a hovers in the water , barely moving . A smaller striped called a goby swims up to the . Then , like a vacuum cleaner moving over a rug , the goby swims slowly over the larger , eating dead skin and tiny parasites . The goby even cleans inside the mouth and gills . Both fishes from this cleaning . The gets rid of unwanted materials , and the goby gets a meal .

Water flow heart Characteristics of Fishes Both the goby and the are . A is a vertebrate that lives in water and uses to move . In addition to living in water and having . most are , obtain oxygen through gills , and have scales . Scales are thin . overlapping plates that cover the skin . Fishes up the largest group . Nearly half of all vertebrate species are . In addition . have been on Earth longer than any other kind of vertebrate . Blood vessels in body Obtaining Oxygen A respiratory and circulatory work together to deliver oxygen to body cells . Fishes get I their oxygen from water . As a fish swims , it opens its mouth and I blow takes a gulp of water . The water , which contains oxygen , moves through openings in the throat region that lead to the FIGURE gills . Gills , which look like tiny feathers . are the main organs in a Respiration and Circulation respiratory system . Gills have many blood vessels . As water water into the mouth ofthis over the gills , oxygen moves from the water into the fish and then over its gills . Oxygen ' blood . At the same time , carbon dioxide , a waste product , moves he a is . delivered to the cells of the fish . i out of the blood and into the water . over the gills . Diagrams Where the water out of the fish through slits beneath the gills . i does oxygen get info the mood of a fish ?

Circulatory System From the gills . the blood travels throughout the fish body . supplying the body cells with Like all vertebrates . have a closed circulatory system . The heart of a fish has two , or inner spaces . The heart of a pumps blood in one the heart to the gills , from the gills to the rest of the body , and back to the heart . You can trace this path in Figure . Chapter 12 463

FIGURE Fins of an Angelfish The skeleton of a fish shows that the fins have bony support . The fins of this angelfish act like paddles as the fish moves through the water . Movement Fins help swim . Look at the on the in Figure . Each has a thin membrane stretched across bony supports . Like a canoe paddle , a provides a large surface to push against the water . The push allows for faster movement through the water . If you have ever swum wearing a pair of swim , you probably noticed how fast you moved through the water . Most of the movements of are related to obtaining food , but some are related to reproduction . Reproduction Like all vertebrates , reproduce sexually . Most have external fertilization . In external fertilization . the eggs are fertilized outside the females body . The male ers near the female and spreads a cloud of sperm over the eggs she releases . The young develop outside the female body . In contrast , some , such as sharks and guppies , have internal fertilization . In internal fertilization , eggs are fertilized inside the female body . The young develop inside her body . When the young are mature enough to live on their own , she gives birth to them . What is the structure of a fin ?

FIGURE Trout Eggs Young brook trout fish are developing in these eggs on the bottom of a stream .

Nervous System The nervous system and sense organs of fishes help them find food and avoid . Most can see much better in water than you can . Keen senses of touch , smell , and taste also help capture food . Some , such as the in Figure , have taste organs in unusual places . Diversity of Fishes Fishes are into three main groups based on the mouth structure and type of skeleton . The major groups of are jawless , cartilaginous , and bony . lawless Fishes lawless were the vertebrates to appear on Earth . lawless are unlike other in that they have no jaws and no scales . laws are hinged bony structures that allow animals to open and close their mouths . of jaws , have mouths containing structures for scraping . stabbing , and sticking their food . Their skeletons are made of cartilage , a tissue that is more flexible than bone . and lampreys are the only kinds of alive today . look like large , slimy worms . crawl into the bodies of dead or dying and use their rough tongues to scrape decaying tissues . Many lampreys are sites of other . They attach their mouths to healthy and then suck in the tissues and blood of their victims . If you look at the lamprey mouth in Figure 10 , you can probably imagine the damage it can do . Reading What material makes up the skeleton of a Checkpoint ) jawless fish ?

FIGURE A The whiskers of a have many taste buds . To find food , the catfish drags its whiskers along muddy lake or river bottoms . FIGURE 10 A Lamprey Lampreys have bodies . They use sharp teeth and mouths to feed on other fishes . Classifying To which group of fishes do lampreys belong ?

Chapter 12 465 FIGURE Great White Shark and Ray Both sharks and rays are cartilaginous fishes . Sharks such as the one below have sharp teeth . This ray lives on the ocean floor . Fishes Sharks , rays , and skates are ( tuh LA uh ) The cartilaginous have jaws and scales , and skeletons made of cartilage . The pointed , toothlike scales that cover their bodies give their skin a rough texture . Like all , cartilaginous obtain oxygen from water , Most sharks can not pump water over their gills . Instead , they rely on swimming or currents to keep water moving across their gills . When sharks sleep , they position themselves in currents that send water over their gills . Rays and skates are not as active as sharks . They spend a lot of time on the ocean floor . During this time , they take in water through small holes behind their eyes . Water leaves through gill openings on the undersides . Bony Fishes Most familiar kinds of , such as trout , tuna , and , are bony . A bony has jaws , scales , a pocket on each side of the head that holds the gills , and a skeleton made of hard bones . Each gill pocket is covered by a that opens to release water . The major structures of a bony are shown in Figure 12 . Notice that this bony fish has an organ called a swim bladder , which is an internal . sac that helps the stay stable at different depths in the water . Gas levels in the swim bladder are adjusted after the fish reaches its desired depth . Because of this adjustment , the can stay at a depth without using a lot of energy . Bony make up about 95 percent of all species . They live in both salt water and fresh water . Some live in the dark depths of the ocean . Others thrive in waters , such as those around coral reefs . Hunting which organ helps a bony fish maintain its position in the water ?

Observing Put on your goggles and disposable gloves . Place a preserved bony fish on paper on your desk and examine it closely . Note its size and shape , and the bar and locations of its fins . Lift the gill cover and observe the gills with a hand lens . Use your observations to make a diagram of the fish . Wash your hands when you are finished . 4660

12 Structure of a Bony Fish The yellow perch has the characteristics of a bony fish . Interpreting Diagrams What are the functions of fins ?

tins These help the fish ' the me i Most of this sales swimming power The scales overlap like comes trom motions shingles on a root . Mucus Of its tail fin in covers and protects the scales . I with muscles on the sides of the fish . Gill cover Gills Swim Bladder The swim bladder helps stabilize the fish at different depths in the water . Writing . Assessment Target Reading Skill Compare and Contrast Use your chart about the different groups of to help you answer Question . Reviewing Key Concepts a . Reviewing What are the main characteristics of ?

Explaining What is the function of gills ?

Applying Concepts What would happen to a that could not open its mouth ?

Explain . Identifying What are three major groups of ?

Classifying into which group of would you classify a with jaws and a skeleton made of cartilage ?

Comparing and Contrasting How does shark reproduction differ from the reproduction of most ?

Chapter 12 467 Students know plants and animals have levels of organization for structure and function , ing cells , tissues , organs , organ systems . and the whole organism . What is the life cycle of an amphibian ?

How are adult amphibians adapted to living on land ?

Key Terms amphibian tadpole lung atrium ventricle habitat This green frog blends in with green duckweed In a pond . 4689 Amphibians What the Advantage of Being Green ?

Count out 20 dried yellow peas and 20 green ones . Mix them up in a paper cup . Cover your eyes . Have your partner gently scatter the peas onto a large sheet of green paper . Uncover your eyes . Have your partner keep time while you up as many peas , one at a time , as you can find in 15 seconds . When 15 seconds are up , count how many peas of each color you picked up . Repeat Steps through , but this time you scatter the peas and keep time while your partner picks up the peas . Compare your results with those of your partner and your classmates . Think it Over Inferring Many frogs are green , as are their environments . What advantage does a frog have in being green ?

In a pond , a frog lies in wait . In the air above the frog , a dragonfly approaches . Because the frog blends in with its surroundings , the does notice the frog . Zip ! The tongue shoots out , capturing the . Frogs and toads have that helps them obtain food and avoid predators . Most frogs and toads are green or , making them hard to see in their ment . If you did the Standards , you learned that it is hard to see something green against a green background . What Is an Amphibian ?

A frog is one kind of amphibian . Toads and manders are other kinds . An amphibian ( am FIB ee uni is a vertebrate that is and spends its early life in water . Indeed , the word amphibian means ble life , and amphibians have exactly that . After beginning their lives in water , most amphibians spend their adulthood on land , returning to water to reproduce .

LI The tail is absorbed , and development is completed . Adult frogs reproduce sexually . side the female body . Front legs develop . Swimming tadpoles hatch from the eggs . legs develop . Flaunt 13 Reproduction and Development Eggs are fertilized fa Cycle of a Frog During its metamorphosis from nally in most salamanders and externally in most frogs and tadpole to adult a 095 body toads . Fertilized eggs develop in water . After a few days , larvae undergoes a 59 , of , wriggle out of a jelly that coats the eggs and begin a changes . Applying Concepts How swimming , life . Prepare The larvae of most amphibians grow and eventually undergo ' land , metamorphosis . You can trace the process of frog metamorphosis in Figure 13 . The larva of a frog or a toad is called a tadpole . Like , tadpoles obtain oxygen through gills . Unlike tadpoles , the larvae of salamanders look like adults . Most salamander larvae undergo a metamorphosis in which they lose their gills . However , the changes are not as dramatic as those that happen during a frog or toad metamorphosis . What is a frog larva called ?

Diversity of Amphibians There are two major groups of amphibians . Salamanders form one group . Frogs and toads form the other . You can distinguish between the groups by the presence of a tail in the adults . Salamanders keep their tails in adulthood , while most frogs and toads do not . Go For More on the frog life cycle Visit Web Code Chapter 12 469 Eggs are fertilized

Living on Land Once an amphibian becomes an adult and moves onto land , its survival needs change . It must now get its oxygen from the air , not the water . Fins no longer help it move . The respiratory and circulatory systems of adult amphibians are adapted for I life on land . in addition , adult amphibians have adaptations for moving . Obtaining Oxygen Amphibian larvae use gills to obtain oxygen from the water . During metamorphosis . most Go Online lose their gills and develop lungs . Lungs are organs . breathing vertebrates in i ox en moves from the air into the blood . Carbon dioxide moves from the blood into the air . Oxygen and carbon dioxide are also exchanged through the and thin , moist skins of adult amphibians . Visit ( web Circulatory System Circulatory system has a loop and a heart with two chambers , like that of a . In contrast , the circulatory system of many adult amphibians has two loops and a heart with three chambers . You can trace the path of blood through an adult amphibian in Figure 14 . The two upper chambers of the heart , called atria ( singular atrium ) receive blood . One atrium receives blood from the lungs , and the other receives blood from the rest of the body . From the atria , blood moves into the lower ber , the ventricle , which pumps blood out to the lungs and body . and blood mix in the ventricle . Blood vessels in lungs nouns 14 Respiration and Circulation This adult salamander has lungs and a loop circulatory system . Interpreting Diagrams Why is the blood in the right atrium colored blue ?

Blood vessels in body I blood I blood Movement A vertebrate that lives on land needs a strong skeleton to support its body . In addition , a land animal needs some way of moving . Fins work in water , but they don ! work on land . Most adult amphibians have strong skeletons and muscular limbs adapted for moving on land . Salamanders usually crawl . The legs of frogs and toads have adaptations for leaping . Leaping requires powerful muscles and a skeleton that can absorb the shock of landing . Amphibians in Danger Worldwide , amphibian tions are decreasing . One reason is the destruction of ian habitats . An animal habitat is the environment in which it lives . When a swamp is in or a forest is cut , an area that mu 15 . Golden Frog was moist ier . ew amp can survive or Golden frogs like the one shown In ' sunny here , are rarely seen anymore in But amphibians are declining even in areas where their their native rain forests habitats have not been damaged . Because their skins are ' a I ate th i ( ii a ii ' an elf 85 ?

amp . Pena two possible causes for the decrease sensitive to changes in their environment . Poisons in the , the number of frogs ?

such as pesticides and other chemicals , can pollute the waters that amphibians need to live and reproduce . iM What is a habitat ?

Section Assessment was Vocabulary Skill Greek Word Origins In Interpreting Diagrams How is an adult the Greek word , the word part bios amphibian system different from means What do you think the word part that of a fish ?

Use Figure and Figure 14 to means ?

help answer this question . Reviewing Key Concepts a . Defining What is an amphibian ?

In SCIENCE Sequencing Describe a frog life cycle , beginning with the egg . Comparing and Contrasting Contrast the that introduces people to amphibians . Hist . ways in which tadpoles and adult frogs come a catchy Web site . obtain oxygen . Then . design your home page . page a . Reviewing What are three adaptations . I of adult amphibians for living on land ?

your design Sequencing How does blood move in will you ?

What the the circulatory system of an adult amphibian ?

photos ( Hint Start with blood leaving the ventricle relating to amphibians will you have ?

of the heart and going to the lungs . Chapter 12 471 Standards Focus Students know that tion of a species occurs when the environment changes and the adaptive characteristics of a species are insufficient for its survival . Students know plants and animals have levels of organization for structure and function , ing cells , tissues , organs , organ systems , and the whole organism . 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 ?

Key reptile I kidney urine amniotic egg Reptiles Standards How Do Snakes Feed ?

To model how a snake feeds , stretch a sock cuff over a grapefruit prey by first pulling on one side and then on the other . Work the grapefruit down into the stomach . A jawbones can spread apart like the sock cuff . Remove the grapefruit and put a rubber band around the sock about centimeters below the opening . The rubber band represents the firmly joined jawbones of a lizard . Now try to repeat Step . Think It Over Inferring What is the advantage of having jawbones ?

The king cobra of Southeast Asia is the worlds longest ous snake . It can grow to more than meters long . When it encounters a predator , king cobra its neck and rears up . Its ropelike body sways back and forth , and its tongue in and out . A king cobra fearsome behavior in response to a predator contrasts with the gentle way it treats its eggs . King cobras are one of the few snakes that build nests . The female builds a nest of grass and leaves on the forest . She lays her eggs inside the nest and guards them until they hatch . King cobra

Adaptations for Life on Land Like other reptiles , king cobras lay their eggs on land rather than in water . A reptile is an vertebrate that has lungs and scaly skin . In addition to snakes such as the king cobra , lizards , turtles , and alligators are also reptiles . Unlike amphibians , reptiles can spend their entire lives on dry land . The ancestors of modern reptiles were the first vertebrates adapted to life completely out of water . Reptiles get their gen from air and breathe entirely with lungs . Reptiles that live in water , such as sea turtles , evolved from reptiles that lived on land . 80 , even though sea turtles live in water , they still breathe with lungs and come ashore to lay eggs . You can think of a land animal as a pocket of water held within a bag of skin . To thrive on land , an animal must have adaptations that keep the water within the bag from rating in the dry air . The skin , kidneys , and eggs of reptiles are adapted to conserve water . Skin and Kidneys Unlike amphibians , which have thin , moist skin , reptiles have dry , tough skins covered with scales . This scaly skin protects reptiles and helps keep water in their bodies . Another adaptation that helps keep water inside a tile body is its kidneys , which are organs that wastes from the blood . The wastes are then excreted in a watery called urine . The kidneys of reptiles concentrate the urine so that the reptiles lose very little water . what are two functions of a reptiles skin ?

FIGURE 16 A Desert Tortoise The tough , scaly skin of this desert tortoise helps it survive in a dry environment . Go on For More on reptiles Visit Web Code Chapter 12 413 An Egg With a Shell Reptiles have internal fertilization and lay their eggs on land . While still inside a female body . fertilized eggs are covered with membranes and a leathery shell . Unlike an amphibian eg , a reptile egg has a shell and membranes that protect the embryo and help keep it from ing out . An eg with a shell and internal membranes that keep the embryo moist is called an amniotic egg ( am nee ik ) Pores in the shell let oxygen gas in and carbon dioxide gas out . Look at Figure 17 to see the membranes of a reptiles egg . One membrane holds a liquid that surrounds the embryo . The liquid protects the embryo and keeps it moist . A second membrane holds the yolk , or food for the embryo . A third membrane holds the embryo wastes . Oxygen and carbon dioxide are exchanged across the fourth membrane . FIGURE 17 The Amniotic Egg A The and she of an Fluid within this membrane amniotic egg protect the developing the ' embryo . Relating Cause and Effect 1055 ! Which part of an amniotic egg help keep the embryo from drying out ?

i The embryo wastes collect inside this membrane . The shell protects the embryo and has pores that oxygen and carbon dioxide can pass through . This membrane holds the yolk . which is the embryo energy and carbon dioxide move across this membrane .

Diversity of Reptiles Reptiles that are alive today include lizards , snakes , and turtles . The dinosaurs are reptiles that are now extinct . Lizards and Snakes Most reptiles alive today are either lizards or snakes . Both lizards and snakes are reptiles that have skin covered with overlapping scales . As they grow , they shed their skin and scales , replacing the worn ones with new ones . Lizards differ from snakes in an obvious way . lizards have four legs and snakes have streamlined bodies with no legs . Snakes move by contracting bands of muscles that are to their ribs and backbones . A few lizards are herbivores that eat leaves . Most ards , however , are carnivores that capture their prey by jumping at it . While some large lizards eat frogs and birds , most smaller lizards hunt insects . All snakes are carnivores . Most snakes feed on small animals , such as mice , but some eat large prey . If you did the Standards Warm Up , you learned that a jawbones can spread wide apart . In addition . the bones of a skull can move to let the snake swallow an animal larger in diameter than itself . Snakes capture their prey in different ways . For example , some snakes have long , curved front teeth for hooking slippery prey . Other snakes , such as rattlesnakes and copperheads , have venom glands attached to hollow teeth called fangs . When these snakes bite their prey , venom down through the fangs and enters the prey . En ! How do rattlesnakes capture prey ?

FIGURE 18 An Snake The jawbones of this snake skull have moved to let the snake swallow an egg . Making Generalizations How are snakes different from lizards ?

FIGURE 19 A Sidewinder Snake The sidewinder snake lifts loops of its body off the desert sand as it moves along . Only a small part of its body touches the sand at one time . Chapter 12 475 Alligators and Crocodiles If you walk along a lake in Florida , you just might see an alligator swimming silently in the water . Most of its body lies beneath the surface , but you can see its large , bulging eyes above the surface . Alligators . and their relatives are the largest living reptiles . The American alligator can grow to be more than meters long . Both alligators and crocodiles are large , carnivorous reptiles that care for their young . So , how do you tell an tor from a crocodile ?

Alligators have broad , rounded snouts , with only a few teeth visible when their months are shut . In contrast , crocodiles have pointed snouts , with most of their . teeth visible when their mouths are shut . Alligators and are carnivores that often hunt at night . Science and History Discovering Vertebrate Fossils People have been discovering fossils since ancient times . Here are some especially important fossil discoveries . I ! Reptile , 415

Unlike most reptiles , crocodiles and alligators care for their eggs and newly hatched young . The female lays her eggs in a nest of rotting plants . The female stays near the nest . From time to time , she comes out of the water and crawls over to the nest to keep it moist . After the tiny young hatch . the female scoops them up in her huge mouth . She carries the young from the nest to a nursery area in the water , where they will be safer . For as long as a year after young alligators have hatched , the female stays near her young . The young alligators make ing quacks when they are alarmed . When their mother hears her young quack , she rushes toward them . She protects her young until they can feed and protect themselves . Em How can you tell an alligator from a crocodile ?

them . Research and Write lfyou i could interview the person who discovered one of the fossils , what would you ask about the fossil and how it was found ?

Write a list of those questions . Then use reference materials to try to find the answers to some of 2000 Chapter 12 477 A na Data Sex Ratio of Newly Hatched Alligators ii The Sett 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 graph on the shows the numbers of young of each sex that hatched from eggs in which the young developed at different temperatures . Reading Graphs At which temperature ( 29 ?

an did only females hatch ?

599 ) Drawing Conclusions What effect does the temperature of developing eggs have . Calculating If 100 eggs developed at 31 , on the sex of the baby alligators ?

about how many of the young would be male ?

Number of Young Turtles Turtles live in the ocean , in fresh water , and on land . Turtles that live on land are commonly called A turtle is a reptile whose body is covered by a protective shell that includes the ribs and the backbone . The bony plates of the shell are covered by large scales made from the same material as the skin scales . Some turtles have shells that can cover the whole body . Most turtles can draw the head , legs , and . tail inside the shell for protection . Turtle shells may be hard or A Galapagos Tortoise The Galapagos tortoise lives on 35 35 , where it eats mainly cacti . Turtles feed in a variety of ways , but all have a beak instead of teeth for tearing food . Some turtles are , such as the largest turtles , the . feed mainly on . The tough skin them from the effects of the stinging cells . Other turtles , such as the Galapagos tortoise , are herbivores . They feed mainly on cacti , using their beaks to scrape off the prickly spines before swallowing the cactus . git ! What an turtles that live on land called ?

Extinct Dinosaurs Millions of years ago , huge turtles and reptiles swam in the oceans . Flying reptiles soared through the skies . Snakes and lizards basked on warm rocks . And there were dinosaurs of every description . Some dinosaurs were the est land animals that ever lived . Unlike today reptiles , some dinosaurs may have been endothermic . Dinosaurs were the earliest vertebrates that had legs directly beneath their bodies . This adaptation allowed them to move more easily than animals such as salamanders and lizards , whose legs stick out from the sides of their bodies . Most herbivorous dinosaurs , such as , walked on four legs . Most carnivores , such as the huge Tyrannosaurus rex , ran on two legs . Dinosaurs became extinct , or disappeared from Earth , about 65 million years ago . Climate change may have caused the extinction of dinosaurs and other organisms . Scientists hypothesize that Earth became much cooler 21 because huge clouds of dust and gases blocked sunlight . As you learned in Chapter , volcanoes or the impact of a huge ' be ' object from space may have caused the clouds . Lack of 23 ' light Would have caused the death of many the and to . Ma , animals that depended on the plants . The dinosaurs did not advantage did a long neck have adaptations that let them survive . Section Vocabulary Skill Greek Word Origins Inferring How do you think a gecko Tyrannosaurus comes from the Greek words captures its prey ?

Explain your answer . meaning a cruel and , a . Reviewing When did the dinosaurs become meaning How do these Greek words extinct ?

relate to the characteristics of Tyrannosaurus rex ?

cam . and Eff What may have Reviewing Key caused the dinosaurs to become extinct ?

a . Defining What is a reptile ?

Explaining What are three adaptations that allow reptiles to survive on land ?

Predicting What might happen to a reptile eg if part of its shell were removed ?

Identifying What are the three main groups of reptiles ?

Classifying A gecko is a small reptile that has no shell protecting its body . It uses its legs to climb trees . Into which reptile group would you classify the gecko ?

Chapter 12 479 Systems . and the whole organism . Then use a hand lens to examine the many hairlike barbs that What are the main characteristics project out from the father ?

central shaft . Gently separate two barbs in the middle Key of the feather . Rub the separated edges with ' your fingertip . How do they feel ?

Use the hand lens to examine the edges of the two down feather CA Standards Focus students know plants and what Are Feathers Like ?

animals have levels of organization for structure and function . Observe the overall ing cells . tissues , organs . organ and structure of a feather . separated barbs . Draw a diagram of what you observe . gird . Rejoin the two separated barbs by gently pulling outward from the shaft . Then wash your hands . Think It Over observing Once the barbs have been separated , is it easy to rejoin them ?

How might this be an advantage to the bird ?

One day in in a limestone quarry in what is now many . Hermann von Meyer was inspecting rocks Meyer , a fossil hunter , spotted something dark in a rock . It was the blackened imprint of a feather ! Excited , he began searching for a fossil of an entire bird . He eventually found skeleton surrounded by the imprint of many feathers . The fossil was given the name Archaeopteryx ( kee tur ) meaning ancient winged Paleontologists now think that Archaeopteryx lived about 145 million years ago . Archaeopteryx didn look much like the birds you know . It looked more like a reptile with wings . Unlike any modern bird , Archaeopteryx had a long , bony tail and a mouth full of teeth . But , unlike a reptile , it had feathers and wings . Paleontologists think that Archaeopteryx and modern birds descended from some kind of reptile . Many scientists think that birds descended from dinosaurs . A model of Archaeopteryx 4800

Characteristics of Birds Modern birds have certain characteristics in common . A bird is an endothermic vertebrate that has feathers and a heart . A bird also lays eggs . Adaptations for Flight The bodies of most birds are adapted for , as shown in Figure 22 . Many of a bones are nearly hollow , making the bird lightweight . In tion , the bones of a bird forelimbs form wings . Flying birds have large chest muscles that move the wings . Finally , feathers help birds . Birds are the only animals with feathers . Feathers are not all the same . If you have ever picked up a feather , it was probably a contour feather . A contour feather is one of the large feathers that give shape to a bird body . The long contour feathers that extend beyond the body on the wings and tail are called feathers . When a bird , these feathers help it balance and steer . You can see in Figure 22 that a contour feather consists of a central shaft and many tions , called barbs . Hooks hold the barbs together . In addition to contour feathers , birds have short , fluffy down feathers that are specialized to trap heat and keep the bird warm . Down feathers are found right next to the bird skin , at the base of the contour feathers . Down feathers are . soft and , unlike contour feathers . Reading How are the structures of contour feathers and down feathers different ?

Nearly hollow bones keep birds light in the air , of hooks links the barbs of a feather together , keeping the feather smooth . FIGURE 22 Adaptations for Flight The bodies of most birds have adaptations for flight . interpreting Diagrams What are two adaptations that make birds light ?

Chapter 12 481 A ' For Respiration and Circulation activity Visit Web Code 041 , The i heart keeps . blood separate from sacs connect I blood . Blood vessels in lungs to the lungs . mun 23 Respiration and Circulation Air sacs and a heart help birds obtain oxygen and move it to their cells . Applying Concepts Why is a heart efficient ?

Obtaining Oxygen Flying uses a lot of energy . Therefore , cells must receive plenty of oxygen to release the energy in food . Birds have a highly efficient way to get oxygen into their bodies and to their cells . Birds have a system of air sacs in their bodies that connects to the lungs . The air sacs enable birds to obtain more oxygen from each breath of air than other animals can . The circulatory systems of birds are also efficient at getting oxygen to the cells . Birds have hearts with four atria and two . Trace the path of blood through a bird circulatory system in Figure 23 . The right side of a bird heart pumps blood to the lungs , where oxygen is picked up . blood returns to the left side of the heart , which pumps it to the cells . The advantage of a heart over a . blood chambered heart is that blood does not mix with I blood . Therefore , blood carried to the cells of the body has plenty of oxygen . Blood vessels in body 4810

Obtaining Food Birds must obtain a lot of food to provide the energy needed for . To capture , grip , and handle food , birds mainly use their bills . Bills are shaped to help birds feed and efficiently . For example , the pointy , curved bill of a um and Mammals hawk acts like a meat hook to pull off bits of its prey . In contrast , a duck bill acts like a kitchen strainer , separating out seeds and tiny animals from muddy pond water . After a bird eats its food , digestion begins . Each organ in a bird digestive system is adapted to process food . Many birds have an internal storage tank , or crop , for storing food inside the body after swallowing it . Find the crop in Figure 24 . The crop is connected to the stomach . A bird stomach has two parts . In the first part , food is bathed in chemicals that begin to break it down . Then the food moves to a , muscular part of the stomach called the gizzard . The gizzard squeezes and grinds the partially digested food . Birds do not have teeth . The gizzard does the same grinding function for birds that your teeth do for you . The gizzard may contain small stones that the bird has lowed . These stones help grind the food by rubbing against it and crushing it . What Is a gizzard ?

24 Digestive System of a Hawk Some birds like this hawk have a crop and a gizzard . The crop stores food . and the gizzard crushes food . Interpreting Diagrams Does food reach the crop or the gizzard first ?

The gizzard is a muscular part of the stomach that i squeezes and grinds the food . 433 Down Feather FIGURE 25 Keeping Want A pine grosbeak puffs out its feathers to trap air in the layer of down feathers next to its skin . Down feathers help keep birds warm . Observe the surface of a chicken egg with a hand lens . Then gently crack the egg into a bowl . Do not break the yolk . Note the membrane attached to the inside of the shell . Then look at the blunt end of the egg . What do you see ?

Fill one part of the egg you observe ?

its function ?

spot where the embryo would have developed if the egg had been fertilized . Wash your hands with soap . Observing Draw a labeled diagram of the egg that names each structure and describes its function . 4840 shell with water . What do . Find the egg yolk . What is . Look for a small white spot on the yolk . This marks the Keeping Conditions Stable Like all animals , birds use their food for energy . You know that birds need energy for . Because birds are , they also need a lot of energy to maintain their body temperature . Each day , an age bird eats food equal to about a quarter of its body weight . When people say , You eating like a bird , they usually mean that you re eating little . But if you were actually eating as much as a bird does , you would be eating huge meals . You might be eating as many as 100 hamburger patties in one day ! To maintain their body temperature , birds use feathers as well as energy hom food . As you read earlier , down feathers are specialized to trap heat . They are found right next to 21 birds skin . In Figure 25 , you can see what a down feather looks like . Unlike contour feathers , down feathers are soft and . So , they mingle and overlap , trapping air . Air is a good material that does not conduct heat well and therefore helps vent heat from escaping . By trapping a blanket of warm air next to the birds skin , down feathers slow the rate at which the skin loses heat . In effect , down feathers cover a bird in lightweight long underwear . Reproduction and Caring for Young Like reptiles , birds have internal fertilization and lay eggs . Bird eggs are similar to reptile eggs . However , the shells of bird eggs are harder . In most bird species , the female lays the eggs in a nest that has been prepared by one or both parents .

Bird eggs will only develop at a temperature close to the body temperature of the parent bird . Thus , a parent bird ally incubates the eggs by sitting on them to keep them warm . In some species , incubating the eggs is the job of just one ent . For example , female incubate their eggs . In other species . such as pigeons . the parents take turns incubating the eggs . Chicks may take from 12 to 80 days to develop , ing on the species . When it is ready to hatch , a chick pecks its way out of the eggshell . Some newly hatched chicks , such as ducks . chickens . and partridges , are covered with down and can run about soon after they have hatched . Other la . chicks , such as baby blue jays and robins , are featherless , blind , and so weak they can barely lift their heads to beg for food . Most parent birds feed and protect their young at least until they are able to . FIGURE 26 Parental Care The partridge chicks ( left ) find their own food from the day they hatch . In contrast . the blue jay chicks ( above ) are featherless , blind , and totally dependent on their parents for food for several weeks . Assessment Vocabulary Skill Greek Word Origins Archaeopteryx comes from the Greek words , meaning , and , meaning How do these Greek words VI relate to the characteristics of ?

Count Down Look for products in Activity identifying Wnat characteristics do birds share ?

your home that contain down . Explaining How is a bird body adapted for ?

feathers . What common purpose Relating Cause and Effect Why do birds need so much the Plain oxygen ?

What adaptation helps them obtain ?

family ' a . Reviewing How does a parent bird usually incubate fU its eggs ?

Explaining Why is the incubating process necessary for the development of birds ?

Chapter 12 485 ( Al Standards Focus Students know the between the life cycles and reproduction methods of sexual and asexual organisms . Students know plants and animals have levels of organization for structure and function , ing cells , tissues , organs , organ , and the whole organism . What characteristics do all mammals ?

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

Key Terms ' mammal Mammals , Standards What Are Mammals Teeth Like ?

Nash your hands before you begin . Then , with a small mirror , examine the shapes of your teeth . Observe the incisors ( the front teeth ) the pointed canine teeth the behind the canine teeth and the molars . which are the large teeth in the very back . Compare and contrast the structures of the different kinds of teeth . kinds of teeth in your mouth . Use your tongue to feel the cutting surfaces of the different . Bite off a piece of cracker and chew it . Observe the teeth that you use to bite and chew . Wash your hands when you are finished . mammary gland diaphragm monotreme Think It Over shapes ?

inferring What is the advantage of having teeth with different I marsupial gestation period placental mammal placenta 4869 A yak Himalayan Asia have depended share ?

Tel High in the Mountains of Tibet , several yaks inch their way , single file , along a narrow cliff path . The cliff plunges thousands of meters to the valley below . so one false step can mean disaster . But the yaks . carrying heavy loads of grain , slowly but steadily cross the cliff and make their way through the mountains . People who live in the mountains oi central on yaks for thousands of years . Not only do yaks carry materials for trade , they also pull plows and provide milk . Mountain villagers weave blankets from yak hair and make shoes and ropes from yak hides . The yak is a member of the group of called mammals . Today about ferent of mammals exist . Some . like the yak and wildebeest , you may never have seen . But others , such as dogs . cats , and mice , are very familiar to you . What characteristics do Ar ,

Characteristics of Mammals ( All mammals are endothermic vertebrates that have a heart and skin covered with fur or hair . Most mammals are born alive , and every young mammal is fed with milk produced by organs in its mother body . These organs are called mammary glands . The word mammal , in fact , comes from the term mammary . Obtaining Food In addition to their other characteristics , most mammals have teeth . Their teeth are adapted to chew their food , breaking it into small bits that make digestion easier . Most mammals have teeth with four different shapes . If you did the Standards , you observed these shapes . incisors are teeth used to bite off and cut food . Canines are pointed teeth that stab food and tear into it . and molars have broad , upper surfaces for grinding and shredding food . The size , shape , and hardness of a mammals teeth its diet . For example , the canines of carnivores are especially large and sharp . Large carnivores , such as the lion in Figure 27 , use their canines to hold their prey while they kill it . In contrast , herbivores , such as a , have molars for grinding and mashing plants . which teeth stab and tear into food ?

I Springbok Skull 27 Teeth of Different Shapes Lions have sharp , pointed canines . have broad molars . Inferring What kind of diet does each of these mammals eat ?

Chapter 12 487 FIGURE 28 Fur and Hair A hippo has hardly any hair . In contrast , a wolf has a thick coat of fur . Inferring What ( an you infer about the environment each animal lives in ?

Hill insulated Mammals Discover whether or not fat is an effective insulator . Put on a pair of rubber gloves . Spread a thick coating of solid white shortening on the outside of one of the gloves . Leave the other glove uncoated . Put both hands in a bucket or sink filled with cold water . Inferring which hand got told faster ?

Explain how this activity relates to mammalian adaptations . Obtaining Oxygen To release energy , food must combine with oxygen inside cells . Therefore , a mammal must have an way to get oxygen into the body and to the cells that need it . Like reptiles and birds , all mammals breathe with lungs . Mammals breathe in and out because of the combined action of rib muscles and a large muscle called the diaphragm ( DY uh fram ) The diaphragm is located at the bottom of the ribs . The lungs have a huge , moist surface area where oxygen can move into the blood . Like birds , mammals have a heart and a two loop circulatory system . This system takes oxygen to the cells . Keeping Conditions Stable Like birds , mammals are . They need the energy in food to keep a steady internal temperature . In addition , all mammals have fur or hair at some point in their lives that helps them keep their internal temperature stable . Each strand of fur or hair is posed of dead cells strengthened with the same tough material that strengthens feathers . The amount of fur or hair that covers a mammal skin varies greatly . In general , animals that live in cold regions . like the wolf shown in Figure 28 , have more fur than animals that live in warmer environments . Fur is not the only adaptation that allows mammals to live in cold climates . Mammals also have a layer of fat beneath their skin . Like fur and feathers , fat is an insulator .

Movement Like all vertebrates , mammals have a musculoskeletal system , which consists of muscles and bones working together . Each muscle consists of a of that are muscle cells . When muscles pull on bones , they make the bones move . Energy for this ment is supplied by the action of mitochondria in cle cells . Mammals have adaptations that allow them to move in more ways than members of any other group of . Most mammals walk or run on four limbs , but some have specialized ways of moving . For example , kangaroos hop . Bats have wings adapted from their front limbs . The front limbs of whales , dolphins , and other sea mammals are adapted as for ming . These specialized ways of moving allow mammals to survive in many habitats . Nervous System A mammal nervous system its movements . In addition , the nervous system receives information about the environment . The brains of mammals enable them to learn , remember , and behave in complex ways . For example , in order for squirrels to eat nuts , they must crack the nutshell to get to the meat inside . Squirrels learn to use different ods to crack different kinds of nuts , depending on where the weak point in each kind of shell is located . The senses of mammals are highly developed and adapted for the ways a species lives . Tarsiers , which are active at night , have huge eyes that let them see in the dark . Bats use keen hearing to navigate and catch prey . Dogs , cats . and bears often use smell to track their prey . Reading What are three ways that mammals Checkpoint ) an move ?

FIGURE 30 The Senses of Seals Seals can see under water in near darkness . Their long whiskers help them obtain food by detecting the movements of their prey . FIGURE 29 A Swinging Orangutan This young orangutan can grasp branches with its limbs and swing from place to place . Chapter 12 489

Go ' INKS . For Links on mammals Web Code A Spiny Anteater The young of this spiny anteater , a monotreme , hatch from eggs . Diversity of Mammals Mammals are a very diverse group . The three main groups of mammals are , marsupials , and placental mammals . The groups differ in how they reproduce and how their young develop . mammals are called ( oh ) There are just three species of . two species of spiny anteaters and the platypus . A ' female spiny anteater lays one to three eggs directly into a pouch on her belly . After the young hatch , they stay in the pouch for six to eight weeks . There they drink milk that seeps out of pores on the mother skin . contrast , the platypus lays her eggs in an underground nest . The tiny young feed by lapping at the milk that oozes from slits onto the fur of their mother belly . Marsupials Koalas , kangaroos , and opossums are some of the marsupials . Marsupials ( ee ) are mammals whose young are born at an early stage of ment , and they usually continue to develop in a pouch on their mothers body . Marsupials have a very short gestation period , the length of time between fertilization and birth . For example , opossums have a gestation period of about 13 days . Newborn marsupials are opossums are less than centimeter long at birth ! When they are born , marsupials are blind , hairless , and pink . They crawl along the wet fur of their mothers belly until they reach her pouch . Once inside , they one of her nipples and attach to it . They remain in the pouch until they have grown enough to peer out of the pouch opening . im What IS a marsupial ?

FIGURE 32 Kangaroos This gray kangaroo , a marsupial , carries her offspring in a pouch . Classifying How do marsupials differ from ?

Placental Mammals Unlike a monotreme or a marsupial , a placental ( SEN tal ) mammal develops inside its mother body until its body systems can function independently . The name of this group comes from the placenta , an organ in pregnant female mammals that passes materials between the mother and the developing embryo . Food and oxygen pass from the mother to her young . Wastes pass from the young to the mother , who eliminates them . An umbilical cord connects the young to the mothers placenta . Most mammals , including humans , are placental mammals . Gestation periods of placental mammals are generally longer than those of marsupials . Usually , the larger the placental mammal , the longer the gestation period . The gestation period for an elephant , for example , averages about 21 months , but for a mouse , its only about 20 days . Placental mammals are into groups on the basis of characteristics such as how they eat and how their bodies move . You can see the diversity of placental mammals in Figure 34 on the next page . FIGURE 33 Mother and Baby Giraffe ' This baby giraffe , a placental mammal , feeds on milk produced by its mother . Mammal Diversity ' This circle graph shows the percentage carnivores of species of some types of mammals . Reading Graphs What percentage of species are bats ?

Marsupials 14 Other Types . Calculating What percentage of species are not bats ?

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

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 . Chapter 12 491 I 34 Rabbits and Ham Diversity of Placental Mammals ' a , like this From tiny moles to huge elephants , placental jack rabbi have long mammals are diverse . They are grouped on the hind legs specialized basis of how they eat and move as well as for . other characteristics . Rabbits and ham have long , curved incisors for gnawing . This river otter belongs to the group known as carnivores . Dogs , raccoons , and seals are other members of this group . Most carnivores have large canine teeth and clawed toes that help them catch and eat their prey . Marine Mammals Whales , manatees , and these Atlantic spotted dolphins are mammals with a body shape adapted for swimming . Rodents Rodents are gnawing mammals such as mice , rats , beavers , and the capybaras shown here . The incisor teeth of most rodents keep Mammals With Trunks A growing throughout their lives but are Elephants noses are long trunks that constantly worn down by gnawing . they use for collecting food and water . 492

Flying Mammals The wings of bats are made of a thin skin that stretches from their wrists to the tips of their long finger bones . A Moles and their relatives have sharp cutting surfaces on all of their teeth . This mole spends much of its time searching for prey with its sensitive , tentacled snout , Toothless Mammals Armadillos , such as the one shown here , are toothless mammals . So are sloths . Although a few members of this group . have small teeth , most have none . Primates This group of mammals with large brains and eyes that face forward . includes humans , monkeys , and apes such as this chimpanzee . Hoofed Mammals A Some mammals with hooves have an even number of toes and some have an odd number of toes . Cows , deer , and pigs all have an even number of toes . Horses and zebras have an odd number of toes .

Caring for Young Whether a monotreme , a marsupial , or a placental mammal , young mammals are usually quite helpless fora long time after being born . Many are born out a coat of insulating fur . Their eyes are often sealed and may not open for weeks . For example , black bear cubs are surprisingly tiny when they are born . The blind , nearly hairless cubs have a mass of only 240 to 330 the same mass as a grapefruit . The mass of an adult black bear , in contrast , ranges from about 120 to 150 about 500 times as much as a newborn cub ! Young mammals usually stay with their mother or both FIGURE 35 . Parental care by Dams Sheep parents for an extended time . After black bear cubs learn to mammal , usually walk , they follow their mother about for the next year , learning much parental care . On a rocky how to be a bear . They learn things that are important to their A ' survival , such as which mushrooms and berries are good to a placental mammal , keeps a dose watch on her lamb . eat and how to rip apart a rotten log and find grubs within it . During the winter , when black bears go through a period of inactivity , the young bears stay with their mother . The following spring , she will usually force them to live independently . Reading Why are most young mammals dependent on one ?

or both parents after they are section Assessment Target Reading Skill Compare and Contrast Use your table to help you answer Question . Reviewing Key Concepts a . Defining What characteristics do mammals share ?

Mammals . with a . Describing Describe the adaptation that most member , examine the nutrition hi ?

label on a container of whole milk . Relating Cause and Effect What enables mammals what type , of does whore to live in colder environments than reptiles ?

muk contain ?

Discuss why milk is an a . Reviewing What are the three main groups of ideal source of food for young , mammals ?

growing mammals . Explaining How do these groups differ in their manner of reproduction ?

Comparing and Contrasting Why might scientists consider to be a link between reptiles and mammals ?

4940 Lab Keeping Warm . Problem Wool products are made from the hair of mals , such as sheep . Do wool products provide insulation from the cold ?

How well does wool insulate when it is wet ?

Skills Focus . Immediately measure the temperature of the ' i ' data water in each container , and record it in your data table . Take tern minutes for at minutes . eve tap water , hot scissors beaker , thermometers clock or watch Analyze and conclude ' 93 ' Graphing Graph your results using a ?

ent color to represent each container . Graph ' time in minutes on the horizontal axis and . a temperature on the vertical axis . Procedure . Interpreting Data Compare the temperature PU i ' changes in the three containers . Relate your with Wat to the insulation characteristics of temperature , wring it out so it not dripping . mammal skin covering and then slide the second container into the wet sock . Both containers should stand upright . Leave the third container uncovered . Communicating Suppose a company claims that its wool socks keep you warm even if ' they get wet . Do your findings support this . Create a data table In your notebook , listing claim write a gene , to the company . the containers in the first column . Provide why , why not four more columns in which to record the water temperatures during the experiment . Design an Experiment . Use scissors to carefully cut a small ' in the Design an experiment to how center of each lid . Make the just large with those of ' 9355 other natural materials ( such as cotton ) or . Fill a beaker with about 800 of hot tap materials ( such as acrylic ) Obtain your water . Then pour hot water nearly to the top teacher permission before carrying out your of each of the three containers . CAUTION investigation . Avoid spilling hot water on yourself or others . Place a lid on each of the containers , and insert a thermometer into the water through the hole in each lid . Gather the socks around the thermometers above the first two , swing so that the containers are completely covered . Web Code 405

Chapter 12 Study Guide . Vertebrates have that include backbones . I I ea . provide support and enable movement . What Is a Vertebrate ?

Key Concepts , have a notochord . a nerve cord that runs down their back , and slits in their throat area . A vertebrate has a backbone that is part of an internal skeleton . By studying fossils and other evidence , scientists infer the relationships between vertebrate groups . The body temperature of most , amphibians . and reptiles is close to that of their environment . In contrast , birds and mammals have a stable body temperature . Key Terms chordate notochord I vertebra Fishes Key Concepts ! In addition to living in water and having , most are , obtain oxygen through gills , and have scales . The major groups of are jawless , cartilaginous , and bony . lawless have no jaws and no scales . Cartilaginous have jaws and scales , and skeletons made of cartilage . A bony has jaws . scales , a pocket on each side of the head that holds the gills . and a skeleton made of hard bone . Key Terms cartilage swim bladder ( Amphibians Key Concepts After beginning their lives in water , most amphibians spend their adulthood on land , returning to water to reproduce . The respiratory and circulatory systems of adult amphibians are adapted for life on land . 4969 Key Terms amphibian tadpole lung atrium ventricle habitat Reptiles Key Concepts , The skin , kidneys , and eggs of reptiles are adapted to conserve water . Both lizards and snakes are reptiles that have skin covered with overlapping scales . Both alligators and crocodiles are large , carnivorous reptiles that care for their young . A turtle is a reptile with a protective shell that includes the ribs and the backbone . Climate changes may have caused the extinction of dinosaurs and other organisms . Key Terms reptile urine kidney amniotic egg Birds Key Concepts A bird is an endothermic vertebrate that has feathers and a heart . A bird also lays eggs . Key Terms bird ' contour feather down feather crop gizzard Key Concepts , All mammals are endothermic vertebrates that have a heart and skin covered with fur or hair . Most mammals are born alive , and every young mammal is fed with milk . There are three main groups of , marsupials . and placental mammals . The groups differ in how their young develop . Key Terms mammal mammary gland diaphragm monotreme marsupial I gestation period placental mammal placenta

Review and Assessment . 91 arget Reading Skill For Web Code Compare and Contrast Complete the table below . which compares the circulatory systems of four vertebrate groups . Reviewing Key Terms Choose the letter of the best answer . Vertebrates are a subgroup of . amphibians . reptiles . A is an . I . has . has lungs . has a heart . A reptile is an . lays eggs . has a swim bladder . has a thin skin . The gizzard of a bird stores air . I ) removes oxygen from air . helps a bird fly . grinds food . A monotreme differs from a placental mammal because the monotreme has fur . has a placenta . lays eggs . feeds its young with milk Complete the following sentences so that your answers clearly explain the key terms . At some point , all have a notochord , which is a ( The life cycles of amphibians are different from those of most vertebrates amphibians . Unlike an amphibians eggs , a reptile amniotic eggs have . A contour feather functions to 10 . The placenta is an organ whose function is to Writing in Science , In ! Gland Saul Birds and Mammals Chapter 12 497

Review and Assessment Checking Concepts 11 . What evidence has enabled scientists to infer the order in which vertebrate groups evolved ?

12 . How do reproduce ?

13 . Describe the adaptations of an adult amphibian for obtaining oxygen from the air . how the structure of a reptile egg protects the embryo inside . 15 . Describe the position of dinosaurs legs on their bodies . How did this give dinosaurs an advantage ?

16 . What adaptations help a bird obtain enough oxygen for flight ?

17 . How does the structure of an incisor relate to its function ?

18 . Describe how mammals breathe in and out . Thinking Critically 19 . Relating Cause and Effect Explain why an endoskeleton allows vertebrates to grow larger than animals without interpreting Diagrams How does blood move in the circulatory system shown below ?

I blood I blood 21 . Classifying A museum has a vertebrate fossil that is over 500 million years old . To which , amphibians , reptiles , birds , or the fossil most likely belong ?

Explain your answer . 22 . Comparing and Contrasting Compare temperature regulation in and . 498 Applying Skills Use the graph to answer Questions . A scientist performed an experiment on to test the effect of water temperature on rate rate at which the open and close their gill covers . The graph shows the data that the obtained at four temperatures . Fish Breathing Rate at Different Temperatures Average Number of Breaths per Minute 20 22 24 Temperature ( 23 . Controlling Variables Identify the manipulated variable and the responding variable in this experiment . 24 . Interpreting Data How does the breathing rate at compare to the breathing rate at ?

25 . Drawing Conclusions Based on the data shown , what is the relationship between water temperature and breathing rate ?

Standards Investigation Performance Assessment Display your models in a creative and interesting example , show the models in action and show details of the animals habitats . Also display your poster . List all the adaptations you learned from your classmates presentations . How did constructing a three dimensional model help you understand the characteristics of these groups ?

Choose the letter of the best answer . Which of the following is the order in which . The dinosaurs probably became extinct . In the diagram above , the front of the mouth . Suppose a bony injured its swim bladder . Success Tracker Standards Practice Use the table below to answer Question . Characteristics of Observed Animals ME I vertebrate groups appeared on Earth , beginning with the group that appeared earliest ?

A amphibians , birds , reptiles , mammals , birds , reptiles , amphibians . mammals birds , mammals , amphibians , reptiles , amphibians , reptiles , mammals , birds because they lacked adaptations to survive 355 . A scientist observed four different animals and disease . recorded her data in the table shown above . in a cool climate . Which of the animals most likely reproduces by in a warm climate . means of amniotic eggs ?

A Animal Use the diagram below to answer Question . Animal Animal Animal . Which of the following organs together enable all vertebrates to move from place to place ?

A crop and gizzard lungs and bones and muscles air sacs and kidneys . All vertebrates reproduce A sexually . asexually . by means of internal fertilization . by means of external fertilization . faces left . What is the most likely function of the large teeth in the center of the mouth ?

A grinding food killing biting food . Describe the structure of a cutting and tearing food backbone and explain how this structure gives to a vertebrate body . The would probably have A digesting food . regulating its body temperature . staying stable at different depths . obtaining oxygen water . Chapter 12 499

Chapter Viruses , Bacteria , and Fungi Organisms in different domains and kingdoms display varying levels of organization , from single cells to more complex structures . What is the structure of a virus ?

How do the cells of bacteria differ from those of ?

What are the characteristics of , plantlike , and funguslike ?

What characteristics do fungi share ?

Chapter 10 Structure and Function of Plants BIG The structure of plants enables them to obtain water and nutrients , make food , grow . develop , and reproduce . What do plants need to live successfully on land ?

What characteristics do the three groups of seedless vascular plants share ?

What characteristics do seed plants share ?

Chapter 11 Structure and Function of Invertebrates The structures of animal bodies enable them to obtain food and oxygen , keep internal conditions stable , move . and reproduce . What are four major functions of animals ?

What are the main characteristics of ?

What are the main characteristics of worms ?

What are the distinguishing structures of insects , crustaceans , arachnids , centipedes , and millipedes ?

Chapter 12 Structure and Function of Vertebrates ' BIG Idea Vertebrates have that include backbones . Backbones provide support and enable movement . What are the characteristics of and vertebrates ?

What adaptations allow reptiles to live on land ?

are the main characteristics of birds ?

characteristics do all mammals share ?

Unit ?

Number of Species All Organisms BIG Ideas The circle graphs compare the number of species in A each group of organisms . These graphs include only saga the species that scientists have named and described . There may be millions more species that have yet to be Animals I , discovered or Keep in mind that the graphs include only the number of species , not the total ber of organisms . For example , there are relatively few named species of bacteria , but there are more bacteria on Earth than any other kind of organism . Number of Plant Species Number of Animal Species Vertebrates it Angiosperms Insects Nonvascular Other invertebrates . Look at the graph that compares all . Which statement is true isms . How do the cells of organisms in the of the animals in the largest smallest group differ from those in other group ?

groups ?

Chapter ) a . They reproduce asexually . a . They have cell walls . They have internal skeletons . I . They are prokaryotic . They have external skeletons . They have no genetic material . They have radial symmetry . The ! ha ma ' Which of the following is found only in . What is the role of vascular tissue in plants ?

vertebrates ?

Chapter 12 ) Chapter 10 ) bony endoskeleton performing photosynthesis closed circulatory system preventing water loss brain and nerves . producing sperm and egg cells . bilateral symmetry ' a i water . Summary Choose one plant . one animal , and one protist . Summarize how each organism reproduces . 501