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Kingdom Animalia Sponges Cnidarians Flatworms Roundworms Sponges Assymetrical Freshwater or saltwater Sessile – do not move Filter feeders No Nervous System Multicellular organization (no true tissues yet) Other Sponge Facts: Sponges can regenerate – replace lost body parts through mitotic cell division. Economic Importance: Commercial sponge harvesting for personal care industry. Sponge Reproduction: Asexually – fragmentation or budding Sexually – sponges are hermaphrodites External fertilization Internal fertilization - eggs remain inside parent sponge’s body. Cnidarians – Stinging Animals Radial Symmetry Mostly saltwater Corals Jellyfish Sea anemones Hydra Cnidarian Movement POLYP is sessile – does not move MEDUSA is motile – squeezes bell (umbrella) to move uses simple ring of contractile tissue (not muscle tissue yet) Feeding Use tentacles to capture food. Tentacles have NEMATOCYSTS – stinging cells that grab and immobilize prey using toxins. Waste products and undigested materials are expelled through the mouth. Organization Nerve net – conducts impulses from all parts of the body. No brain. Two layers of tissues derived from endoderm and ectoderm Cnidarian Reproduction Asexually – budding (polyp form) Sexually –have separate male and female medusae that produce gametes that join through external fertilization to produce polyps. Flatworms Platyhelminthes Bilateral Symmetry Free-living in freshwater or parasitic in a host Has all three layers (endoderm, mesoderm, ectoderm) Acoelomate – no body cavity. An Important Group Many nasty parasitic infections. Dugesia Tapeworms Flukes Flatworm Feeding Free living flatworms are scavengers. Parasitic flatworms use specialized structures (usually with hooks) to attach to a host. Respiration & Excretion Excretion - Flame cells remove excess water Respiration - Oxygen diffuses into body cells directly. Flatworm Nervous Systems First appearance of cephalization. Primitive brain. Eyespots Flatworm Reproduction Sexually - Hermaphrodites – internal fertilzation. Asexually – fission – when damaged, regenerates new body parts. Proglottids – found in tapeworms – each is shed off individually. Roundworms - Nematoda Bilateral Symmetry Free-living in soil or parasitic in a host Pseudoomate – false body cavity. Movement - Longitutdinal muscles produce a thrashing movement Respiration & Excretion Respiration - Oxygen diffuses into body cells. Digestive wastes are excreted through the anus. Flame cells remove excess water through pores in body surface. Roundworm Feeding Have a simple digestive system. Have a mouth and an anus Parasitic roundworms use specialized structures (usually with hooks) to attach to a host. An Important Group Many nasty parasitic infections in humans, livestock Importance and IMPORTANT AGRICULTURAL PEST Pinworms, Ascaris, hookworms, Trichinella