AP Biology. Animal Characteristics. Kingdom: Animals. Body Cavity. Animal Evolution. Invertebrate: Porifera. Invertebrate: Cnidaria.

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1 Kingdom: Animals Eukarya Bacteria Archaea Eukarya Animal Characteristics Heterotrophs must ingest others for nutrients Multicellular complex bodies No cell walls allows active movement Sexual reproduction no alternation of generations no haploid gametophyte Common ancestor Animal Evolution Porifera Cnidaria Ancestral Protist Platyhelminthes Nematoda sponges jellyfish flatworms roundworms multicellularity tissues Annelida Echinoderm Mollusca Arthropoda Chordata mollusks bilateral symmetry segmented worms segmentation body cavity insects spiders coelom starfish endoskeleton vertebrates backbone Body Cavity How much is the digestive tract separated from the rest of the body? 3 body layers acoelomate pseudocoelomate coelomate pseudocoel coelom cavity Invertebrate: Porifera Sponges no distinct tissues or organs do have specialized cells no symmetry sessile (as adults) food taken into each cell by endocytosis Invertebrate: Cnidaria Jellyfish, hydra, sea anemone, coral tissues, but no organs two cell layers radial symmetry predators tentacles surround gut opening extracellular digestion release enzymes into gut cavity 1

2 Stinging cells of Cnidarians mouth Invertebrate: Platyhelminthes Flatworms tapeworm, planaria mostly parasitic bilaterally symmetrical tentacles sensory cell discharged nematocyst stinging cell allows high level of specialization within parts of the body now have a mouth at one end & an anus at the other! hydra trigger undischarged nematocyst stinging cell with nematocyst Invertebrate: Nematoda Roundworms bilaterally symmetrical have both mouth & anus many are parasitic Invertebrate: Mollusca Mollusks C. elegans clams, snails, squid bilaterally symmetrical (with exceptions) soft bodies, mostly protected by hard shells true coelem well-developed digestive system hookworm Invertebrate: Annelida Segmented worms earthworms, leeches segments are not specialized bilaterally symmetrical true coelem fan worm Invertebrate: Arthropoda Spiders, insects, crustaceans most successful animal phylum bilaterally symmetrical segmented allows jointed appendages leech exoskeleton chitin + protein 2

3 Arthropod groups Invertebrate: Echinodermata Starfish, sea urchins, sea cucumber arachnids 8 legs, 2 body parts spiders, ticks, scorpions radially symmetrical spiny exoskeleton crustaceans gills, 2 pairs antennae crab, lobster, barnacles, shrmp insects 6 legs, 3 body parts Invertebrate quick check Chordata Vertebrates Invertebrates: Porifera, Cnidaria, Platyhelminthes, Nematoda, Annelida, Mollusca, Arthropoda, Echinodermata fish, amphibians, reptiles, birds, mammals hollow dorsal nerve cord internal bony skeleton Which group includes snails, clams, and squid? Which group is the sponges? Which are the flatworms? spinal column segmented worms? roundworms? skull-encased brain Which group has jointed appendages & an becomes gills or Eustachian tube exoskeleton? Which two groups are radially symmetrical? Which group has no symmetry? Oh, look your first baby picture! pharyngeal pouches postanal becomes tail tail or tailbone 450 mya becomes brain & spinal cord backbone encasing becomes vertebrae notochord salmon, trout, sharks Vertebrates: Fish Characteristics Transition to Land gills Evolution of tetrapods body structure bony & cartilaginous skeleton jaws & paired appendages (fins) scales body function gills for gas exchange body Humerus Femur Pelvis Lobe-finned fish Fibula Pelvis Femur Humerus reproduction external fertilization external development in aquatic egg Shoulder Radius two-chambered heart; single loop blood circulation ectotherms Ulna Tibia Tibia Fibula Ulna Shoulder Radius Early amphibian 3

4 350 mya Vertebrates: Amphibian legs (tetrapods) moist skin lung glottis closed buccal cavity lungs (positive pressure) & diffusion through skin for gas exchange three-chambered heart; veins from lungs back to heart ectotherms external fertilization external development in aquatic egg metamorphosis (tadpole to adult) frogs salamanders toads 250 mya Vertebrates: Reptiles dry skin, scales, armor lungs for gas exchange thoracic breathing; negative pressure three-chambered heart ectotherms external development in amniotic egg dinosaurs, turtles lizards, snakes alligators, crocodile leathery embryo shell chorion allantois yolk sac amnion 150 mya Vertebrates: Birds feathers & wings thin, hollow bone; flight skeleton very efficient lungs & air sacs four-chambered heart endotherms external development in amniotic egg trachea anterior air sacs finches, hawk ostrich, turkey lung posterior air sacs 220 mya / 65 mya Vertebrates: Mammals hair specialized teeth muscles contract lungs, diaphragm; negative pressure four-chambered heart endotherms internal development in uterus nourishment through placenta birth live young mammary glands make milk mice, ferret elephants, bats whales, humans diaphragm contracts Vertebrates: Mammals Sub-groups monotremes egg-laying mammals duckbilled platypus, echidna marsupials pouched mammals short-lived placenta koala, kangaroo, opossum placental true placenta shrews, bats, whales, humans Vertebrate quick check Which vertebrates lay eggs with shells? Which vertebrates are covered with scales? What adaptations do birds have for flying? What kind of symmetry do all vertebrates have? Which vertebrates are ectothermic and which are endothermic Why must amphibians live near water? What reproductive adaptations made mammals very successful? What characteristics distinguish the 3 subgroups of mammals? 4

5 That s the buzz! Any Questions?