Date post: | 27-Mar-2015 |
Category: |
Documents |
Upload: | jake-hansen |
View: | 223 times |
Download: | 2 times |
Fishes, Amphibians, and Reptiles
What Is a Vertebrate?
Fishes
Amphibians
Reptiles
Vertebrate History in Rocks
Table of Contents
Fishes, Amphibians, and Reptiles - What Is a Vertebrate?
Ancient Jawless Fish
Look backward in time, into an ocean 530 million years ago. There you see a strange-looking creature—a jawless fish—that is about as long as your index finger.
Fishes, Amphibians, and Reptiles - What Is a Vertebrate?
Characteristics of Chordates
This lancelet shows the characteristics of a chordate: a notochord, a nerve cord down its back, and gill slits.
Fishes, Amphibians, and Reptiles
Building VocabularyA 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: Examples:
- What Is a Vertebrate?
chordate All members of this phylum are called chordates.
notochord The phylum name Chordata comes from the notochord, a flexible rod that supports a chordate’s back.
vertebra You can see in Figure 2 that the backbone is formed by many similar bones called vertebrae.
Key Terms: Examples:ectotherm
endotherm
An ectotherm is an animal whose body does not produce much internal heat.
The beaver is an example of an endotherm—an animal whose body regulates its own temperature by controlling the internal heat it produces.
Fishes, Amphibians, and Reptiles
Links on Vertebrates
Click the SciLinks button for links on vertebrates.
- What Is a Vertebrate?
Fishes, Amphibians, and Reptiles
End of Section:What Is a
Vertebrate?
Fishes, Amphibians, and Reptiles - Fishes
Characteristics of Fishes
Most fishes obtain oxygen through gills.
Fishes, Amphibians, and Reptiles - Fishes
Bony Fishes
A bony fish has jaws, scales, a pocket on each side of the head that holds the gills, and a skeleton made of hard bones.
Fishes, Amphibians, and Reptiles
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.
Previewing Visuals
Structure of a Fish
Q. 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.
- Fishes
Fishes, Amphibians, and Reptiles
End of Section:Fishes
Fishes, Amphibians, and Reptiles - Amphibians
What Is an Amphibian?During its metamorphosis from tadpole to adult, a frog’s body changes dramatically.
Fishes, Amphibians, and Reptiles - Amphibians
Living on Land
Many adult amphibians have lungs, a heart with three chambers, and a double-loop circulatory system.
Fishes, Amphibians, and Reptiles
SequencingMake 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 Metamorphosis
Adult frog
Fertilized egg
Tadpole hatches.
Hind legs develop.
Front legs develop.
Tail is absorbed.
- Amphibians
Fishes, Amphibians, and Reptiles
More on The Frog Life Cycle
Click the PHSchool.com button for an activity aboutthe frog life cycle.
- Amphibians
Fishes, Amphibians, and Reptiles
End of Section:Amphibians
Fishes, Amphibians, and Reptiles - Reptiles
Adaptations for Life on Land
The membranes and shell of an amniotic egg protect the developing embryo.
Fishes, Amphibians, and Reptiles - Reptiles
Characteristics of a Lizard
This lizard, a Jackson’s chameleon, has many adaptations that help
it survive in its
environment.
Fishes, Amphibians, and Reptiles
The Sex Ratio of Newly Hatched Alligators
The temperature of the developing eggs of the American alligator affects the sex ratio of the young. (Sex ratio is the number of females compared with the number of males.)
- Reptiles
Fishes, Amphibians, and Reptiles
The Sex Ratio of Newly Hatched Alligators
29.4ºC
Reading Graphs:
At which temperature(s) did only females hatch?
- Reptiles
Fishes, Amphibians, and Reptiles
The Sex Ratio of Newly Hatched Alligators
The warmer the incubation temperature, the greater the proportion of males.
Drawing Conclusions:
What effect does the temperature of developing eggs have on the sex of the baby alligators?
- Reptiles
Fishes, Amphibians, and Reptiles
The Sex Ratio of Newly Hatched Alligators
According to the graph, out of the 50 alligators that were incubated at 31.7ºC, about 40 (or 80%) were males. So 80% of 100 eggs (80) could be expected to hatch as males.
Calculating:
If 100 eggs developed at 31.7ºC, about how many of the young would be male?
- Reptiles
Fishes, Amphibians, and Reptiles - Reptiles
Extinct Reptiles–The Dinosaurs
Dinosaurs were the earliest vertebrates that had legs positioned directly beneath their bodies.
Fishes, Amphibians, and Reptiles
Main Idea
Detail Detail Detail
Identifying 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.
Reptiles are adapted to conserve water.
Reptiles 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.
- Reptiles
Fishes, Amphibians, and Reptiles
More on Reptiles
Click the PHSchool.com button for an activity about reptiles.
- Reptiles
Fishes, Amphibians, and Reptiles
End of Section:Reptiles
Fishes, Amphibians, and Reptiles - Vertebrate History in Rocks
Interpretation of Fossils
Fossils most often form in layers of sedimentary rock.
Fishes, Amphibians, and Reptiles - Vertebrate History in Rocks
Interpretation of Fossils
The pattern of vertebrate evolution is branching.
Fishes, Amphibians, and Reptiles
Asking QuestionsBefore 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.
How 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.
Questions Answers
- Vertebrate History in Rocks
Fishes, Amphibians, and Reptiles
Links on Fossils
Click the SciLinks button for links on fossils.
- Vertebrate History in Rocks
Fishes, Amphibians, and Reptiles
End of Section:Vertebrate
History in Rocks
Fishes, Amphibians, and Reptiles
Graphic Organizer
The larvae of amphibians are adapted for life in water, and adult amphibians are adapted for life on land.
Larvae have tails for swimming; adults have
legs for walking.
Detail Detail Detail
Main Idea
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.
Fishes, Amphibians, and Reptiles
End of Section:Graphic Organizer