Presentation on theme: "Table of Contents What Is a Vertebrate? Fishes Amphibians Reptiles"— Presentation transcript:
1Table of Contents What Is a Vertebrate? Fishes Amphibians Reptiles Vertebrate History in Rocks
2Ancient Jawless Fish - What Is a Vertebrate? Look backward in time, into an ocean 530 million years ago. There you see a strange-looking creature—a jawless fish—that is about as long as your index finger.
3Characteristics of Chordates - What Is a Vertebrate?Characteristics of ChordatesThis lancelet shows the characteristics of a chordate: a notochord, a nerve cord down its back, and gill slits.
4Building Vocabulary - What Is a Vertebrate? A definition states the meaning of a word or phrase by telling about its most important feature or function. After you read the section, reread the paragraphs that contain definitions of Key Terms. Use the information you have learned to write a definition of each Key Term in your own words.Key Terms:Key Terms:Examples:ectothermendothermExamples:chordateAn ectotherm is an animal whose body does not produce much internal heat.All members of this phylum are called chordates.notochordThe phylum name Chordata comes from the notochord, a flexible rod that supports a chordate’s back.The beaver is an example of an endotherm—an animal whose body regulates its own temperature by controlling the internal heat it produces.vertebraYou can see in Figure 2 that the backbone is formed by many similar bones called vertebrae.
5Click the SciLinks button for links on vertebrates. - What Is a Vertebrate?Links on VertebratesClick the SciLinks button for links on vertebrates.
7Characteristics of Fishes Most fishes obtain oxygen through gills.
8- FishesBony FishesA bony fish has jaws, scales, a pocket on each side of the head that holds the gills, and a skeleton made of hard bones.
9Previewing Visuals - Fishes Before you read, preview Figure 12. Then write two questions that you have about the diagram in a graphic organizer like the one below. As you read, answer your questions.Structure of a FishQ. What is a swim bladder?A. A swim bladder is an internal, gas-filled sac that helps stabilize the fish at different depths in the water.Q. What is the function of the tail fin?A. It helps provide the power for swimming.
11What Is an Amphibian? - Amphibians During its metamorphosis from tadpole to adult, a frog’s body changes dramatically.
12Living on Land - Amphibians Many adult amphibians have lungs, a heart with three chambers, and a double-loop circulatory system.
13Sequencing - Amphibians Make a cycle diagram like the one below that shows the different stages of a frog’s metamorphosis during its life cycle. Write each step of the process in a separate circle.Frog MetamorphosisAdult frogTail is absorbed.Fertilized eggFront legs develop.Tadpole hatches.Hind legs develop.
14More on The Frog Life Cycle - AmphibiansMore on The Frog Life CycleClick the PHSchool.com button for an activity about the frog life cycle.
16Adaptations for Life on Land - ReptilesAdaptations for Life on LandThe membranes and shell of an amniotic egg protect the developing embryo.
17Characteristics of a Lizard - ReptilesCharacteristics of a LizardThis lizard, a Jackson’s chameleon, has many adaptations that helpit survive in itsenvironment.
18The Sex Ratio of Newly Hatched Alligators - ReptilesThe Sex Ratio of Newly Hatched AlligatorsThe 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.)
19The Sex Ratio of Newly Hatched Alligators - ReptilesThe Sex Ratio of Newly Hatched AlligatorsReading Graphs:At which temperature(s) did only females hatch?29.4ºC
20The Sex Ratio of Newly Hatched Alligators - ReptilesThe Sex Ratio of Newly Hatched AlligatorsDrawing Conclusions:What effect does the temperature of developing eggs have on the sex of the baby alligators?The warmer the incubation temperature, the greater the proportion of males.
21The Sex Ratio of Newly Hatched Alligators - ReptilesThe Sex Ratio of Newly Hatched AlligatorsCalculating:If 100 eggs developed at 31.7ºC, about how many of the young would be male?According to the graph, out of the 50 alligators that were incubated at 31.7ºC, about 40 (or 80%) were males. So 80% of 100 eggs (80) could be expected to hatch as males.
22Extinct Reptiles–The Dinosaurs Dinosaurs were the earliest vertebrates that had legs positioned directly beneath their bodies.
23Identifying Main Ideas - ReptilesIdentifying Main IdeasAs you read the information under the heading “Adaptations for Life on Land,” write the main idea in a graphic organizer like the one below. Then write three supporting details that further explain the main idea.Main IdeaReptiles are adapted to conserve water.DetailDetailDetailReptiles have a thick, scaly skin that prevents water loss.Reptile eggs have a shell and membranes that keep them from drying out.A reptile’s kidneys concentrate wastes before excreting them so that little water is lost.
24Click the PHSchool.com button for an activity about reptiles. More on ReptilesClick the PHSchool.com button for an activity about reptiles.
26Interpretation of Fossils - Vertebrate History in RocksInterpretation of FossilsFossils most often form in layers of sedimentary rock.
27Interpretation of Fossils - Vertebrate History in RocksInterpretation of FossilsThe pattern of vertebrate evolution is branching.
28Asking Questions - Vertebrate History in Rocks Before you read, preview the red headings. In a graphic organizer like the one below, ask a what or how question for each heading. As you read, write answers to your questions.QuestionsAnswersHow do fossils form?Fossils form from imprints or the remains of organisms.How are fossils interpreted?Scientists examine fossil structure and make comparisons to present-day organisms.
29Click the SciLinks button for links on fossils. - Vertebrate History in RocksLinks on FossilsClick the SciLinks button for links on fossils.
31Graphic Organizer Main Idea The larvae of amphibians are adapted for life in water, and adult amphibians are adapted for life on land.DetailDetailDetailLarvae have tails for swimming; adults have legs for walking.Larvae have gills; adults have lungs.Larvae have one-loop circulatory systems and two-chambered hearts; adults have two-loop circulatory systems and three-chambered hearts.