- In vertebrates, the notochord is replaced by the vertebral column. Most vertebrates also have a head region, endoskeleton, and paired appendages.
- There are three groups of fishes: jawless (e.g., hagfishes and lampreys), cartilaginous (sharks and rays), and bony fishes (ray-finned and lobe-finned). Most modern-day fishes are ray-finned (e.g., trout, perch, etc.)
- Amphibians (e.g., frogs and salamanders), who were more numerous during the Carboniferous period, evolved from lobe-finned fishes.
- Modern-day reptiles (e.g., turtles, lizards, snakes) are the remnants of an ancient group that evolved from amphibians.
- The shelled egg of reptiles, which contains extraembryonic membranes, is an adaptation for reproduction on land.
- There is a close evolutionary relationship between birds and reptiles. However, birds maintain a constant body temperature.
- Birds have feathers and skeletal adaptations that enable them to fly.
- Mammals, which evolved from reptiles, were present when the dinosaurs existed. They did not diversify until the dinosaurs became extinct.
- Mammals are vertebrates with hair and mammary glands. The former helps them maintain a constant body temperature.
- Mammals are classified according to methods of reproduction: monotremes lay eggs, marsupials have a pouch into which a newborn crawls and develops further; and placental mammals retain the offspring in a uterus until birth.
- What is the vertebrate skeleton made of?
- What kind of digestive and circulatory systems are found in vertebrates?
- What senses are most used by cartilaginous fish to find prey?
- What is the function of a swim bladder?
- What are the differences between the three major groups of amphibians?
- Animals which regulate their internal temperature by moving about in the environment are called what?
- What major adaptation allowed reptiles to diversify on land?
- What is the protein found in reptile scales, mammal hair, and bird feathers that make them water proof?
- What is the advantage of a four-chambered heart?
- The organ which allows nutrient and gas exchange to occur between a female and the embryos she carries in one group of mammals is called the ______________.
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Summaries of major points:|
- Subphylum Vertebrata
- Jawless fishes
- Fishes with jaws
- Cartilaginous fishes
- Bony fishes