Amphibians frogs toads salamanders Jointed limbs lungs three chambered heart

Amphibians frogs toads salamanders jointed limbs

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Amphibians (frogs, toads, salamanders): Jointed limbs; lungs; three-chambered heart with double-loop circulation;moist, thin skin. 5,383+Reptiles (snakes, turtles, crocodiles): Amniotic egg; rib cage in addition to lungs; three- or four-chambered heart typical; scaly, dry skin; copulatory organ in males and internal fertilization. 8,000+Birds (songbirds, waterfowl, parrots, ostriches): Endothermy, feathers, and skeletal modifications for flying; lungs with air sacs; four-chambered heart. 10,000+Mammals (monotremes, marsupials, placental): Hair and mammary glands. 4,800+*After these characters are listed, they are present in the rest, unless stated otherwise.+Number of species.VERTEBRATESINVERTEBRATESRadiataProtostomia (ecdysozoa)DeuterostomiaProtostomia (trochozoa)Most Invertebrates Are AquaticLearning OutcomesCompare and contrast the characteristics of sponges and cnidarians. (19.4–19.5)Among the protostomes, compare and contrast the trochozoa: flatworms, molluscs, and annelids. (19.6–19.10)Discuss the advantages of a coelom and how coelom development can be used to distinguish animals. (19.8)Among the protostomes, compare and contrast the ecdysozoa: roundworms and arthropods. (19.11–19.14)Among the deuterostomes, describe the echinoderms. (19.15)For convenience, the animal groups discussed in this text have been divided into invertebrates(animals that do not have an endoskeleton of cartilage and bone) and vertebrates(animals that do have an endoskeleton). The invertebrates with three tissue layers are divided into the protostomes and the deuterostomes. A few chordates are invertebrates, but most are vertebrates. As you know, animals evolved in the sea, and as surprising as it may seem, most animals still live in the water. Among the invertebrates, only the molluscs, annelids, and arthropods have terrestrial representatives. Among the vertebrates, the amphibians, reptiles, birds, and mammals have terrestrial representatives. 384PART 3Organisms Are Related and Adapted to Their Environment
osculum H2O in through pores H2O out Yellow tube sponge Sponge organization collar cell (choanocyte) flagellum central cavity amoeboid cell collar nucleus spicule pore amoeboid cell epidermal cell sponge wall 19.4 Sponges are multicellular animalsWhile all animals are multicellular, sponges(phylum Porifera) are the only animals to lack true tissues and to have a cellular level of organization. Sponges, unlike other animals, are asym-metrical, meaning that they have no particular symmetry. Actu-ally, they have few cell types and no nerve or muscle cells to speak of. Sponges may be more closely related to protists than to the multicellular animals.Body of a Sponge Sponges are in phylum Porifera because their saclike bodies are perforated by many pores (Fig. 19.4). Sponges are aquatic, largely marine animals that vary greatly in size, shape, and color. But they all have a canal system of vary-ing complexity that allows water to move through their bodies.

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