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Animals. What does it mean to be an animal?. Multicellular Eukaryotic Ingestive Heterotrophs Lacking cell walls Have a mobile stage in their life cycle. Divisions. Vertebrates – with backbone protecting nerve cord Invertebrates (lacking backbones) make up 95% of all animals. Porifera.
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What does it mean to be an animal? • Multicellular • Eukaryotic • Ingestive Heterotrophs • Lacking cell walls • Have a mobile stage in their life cycle
Divisions • Vertebrates– with backbone protecting nerve cord • Invertebrates (lacking backbones) make up 95% of all animals Porifera
Essential functions • Feeding - all are ingestive heterotrophs • Respiration – obtaining oxygen • Circulation – movement of materials into and around organisms. • Excretion – Getting rid of wastes produced by the organism’s metabolism • Response – Responding to events in environment • Movement – Sessile (immobile) or mobile Some have muscles for movement • Reproduction – Most by sexual reproduction. As you go up the evolutionary tree, we see a trend from asexual reproduction to sexual reproduction
Trends in Animal Evolution • Cell specialization and levels of organization • Cells differentiated to serve a particular function • Unicellular organisms do not have specialization beyond organelles. • Multicellular organisms have structures to serve a particular function • Nerve cells, blood cells, epidermal cells • Cells, tissues, organs then organ systems
Body Symmetry How the body can be divided to get two equal parts • Not found in Porifera (Asymmetric) • Radial symmetry can be cut in any plane from top to bottom to get two equal parts – Cnidarians • Bilateral symmetry – can only be cut in one plane – everything besides Porifera and Cnidarians
3. Cephalization Concentration of sensory structures (nerves) towards to anterior (front) region of the animal) 4. Body Cavity
Body views • Anterior – front of animal closest to head • Posterior – hind end of animal, what comes last • Dorsal – back end or end that faces up • Ventral – bottom end or end that is against the ground
Porifera Porifera means “pore-bearer”
Sea sponges Porifera “Pore bearing”
Osculum- pores which allows water to exit the sponge • Choanocyte/ Collar cells – flagellated cells which generate the flow of water through the sponges’ pores • Spicule- tiny spike like structures for support • Amoebocyte - processes food, then distributes it to other cells • Incurrent pore - pore with flagella that pulls water in
Systems • Food: • Filter feeders • Phagocytizing and trapping their prey • Intracellular digestion • Use collar cells to create a current • Food enters incurrent pores & water/wastes exits the osculum • Reproduce: • Sexual – Sperm released into water & taken into sponge by current • Release fertilized eggs into the water, water current combines them • Asexual reproduction by budding • Hermaphroditic • Larvae are mobile • Response: • No nervous system. • Produce toxins for defense • Respiration & Circulation • Mobility: • Immobile as adult - Sessile • Mobile as larvae Sea sponge
Interaction with humans • Extract used to stunt the growth of cancerous tumors • Indicators of marine environmental health • Original bath sponge came from sea sponges Stagehorn sponge
Cnidaria CnidariaStinging celled animals • Phylum- Cnidaria • Meaning-stinging needle Jellyfish Stinging Hydroid Sea Pen Fire Coral Sea Anemones
Cnidarians all have radial symmetry Coral Sea anemones Hydra Jellies Mushroom Coral Box Jellies Pink-Tipped Surf Anemone Siphonophores Hydroids Fire Coral Sea Pen Jellyfish
All have tentacles with stinging cells called Cnidocytes Within cnidocytes are Nematocysts (poison-filled barb) Mouth/Anus Outer layer- Epidermis Inner layer- Gastrodermis Gastrovascular cavity for digestion Basal disc for attachment Nerve net of connected nerves Structures Hydra
2 basic forms • Tentacles Down = Medusa • Tentacles Up = Polyp • Reproduce asexually by budding • Free swimming larvae Relation to Humans • Coral – jewelry • Global warming/pollution bleaching out coral beds • Have biomedical compounds -anti cancer properties • Habitats for fish/ snorkeling
Nematoda“thread”Round worms Threadworm Roundworms Soybean cyst nematode Porkworm
External and Internal Structures of Nematoda • Unsegmented worms • Microscopic to ~ 1 m • Many are parasitic • Found in soil & water • Have a digestive tract with mouth and anus • Obtain oxygen through body wall & diffuse out wastes • Simple nervous system w/ ganglia in head running down the length of the body • Have muscles running the length of the body for whip-like motion • Sexual reproduction but separate sexes. • Internal fertilization
Move by wave-like motions (contractions) • Parasitic nematodes infect humans • Pinworm • Hookworm • Filarial worm • Beneficial nematodes help soil
Platyhelminthes Platyflat Helminthesworms. Therefore: Flatworms Tapeworm Planaria Turbellaria
Characteristics • Soft, flattened bodies • Have tissues and internal organs • Oxygen & wastes diffuse through skin • Mouth with tube-like pharynx for food getting • Have a gastrovascular cavity for digestion & absportion • Flame cells to filter, remove excess water & metabolic wastes • Gangliaanteriorly with twoocelli(eyespots) to detect light. • Nerves run down sides
Mostly sexual as hermaphrodites Capable of regeneration
Interaction With Humans • Infect humans and livestock • Fatal to humans if not treated • Schistosomiasis (Bilharzia) • Symptoms: fever, chills, liver and spleen enlargement, and abdominal pain, and more.
Tapeworm • Live in intestines of vertebrates • Enter host through undercooked or raw meat containing eggs • Scolex for attachment • Proglottids –segments containing reproductive cells
Phylum- Annelida • Latin root Annellus • Meaning little ring • Segmented worms: • Earthworms • Sandworms • Leeches
Internal and External Structures • Body divided into segments – separated by septa (walls) • Complete digestive tract • Mouth, pharynx, esophagus, crop, gizzard, intestines, anus • Body wall (epidermis) is thin to allow for gas exchange • Kept moist with mucous • Closed circulatory system consisting of five aortic arches (hearts) with a dorsal and ventral blood vessel • Simple anterior brain & ventral nerve cords clittelum
Feeding- pharynx or filter feeding -soil -decaying vegetation • Reproduction- • - Sexually – cross fertilize • - Hermaphroditic • - Clittelum – thick band that produces mucous ring for eggs • Movement- • - Setae - paired bristles • - Muscles – longitudinal & circular
Human Interactions • Keep soil aerated • Leeches- prevent blood clots • Leeches are parasites
Soft bodied animals Mollusca Gastropods Bivalves Cephalopods
Have internal (squid) or external shell Snails, slugs, clams, squid & octopi Body in four parts Foot, mantle, shell and body mass Use foot to attach and mucus to slide for movement In snails and slugs - Radularasping device to abrade the food Bivalves use a siphon to pull in food with water Radula
Bivalves and Gastropods • External fertilization & development into water • Cephalopods – internal fertilization • Some hermaphodites • Cephalopods have a jet propulsion system & haveink sacs/glands Bivalves are filter feeders & clean up water of algae Use bivalves to monitor water conditions since they filter toxins & pollutants Jewelry and currency Excellent food!
ArthropodsJointed Legged animals • Jointed appendages • Exoskeletons of chitin • Segmented bodies (head, thorax, abdomen) • Open circulatory systems • Insects, spiders, crustaceans, millipeds, centipeds, trilobites
Butterflies, flies, moths, bees, ants, beetles, grasshoppers, dragon flies, … Body in three parts: Head, Thorax and Abdomen 6 jointed legs 2 pairs of wings Compound eye 2 antenna Insects
Reproduction, Respiration & Feeding Reproduction - Sexual – separate sexes - Metamorphosis – complete & incomplete Food getting Has specialized mouthparts - Blood suckers, filter feeders, siphon feeders, chewing Respiration Takes air into tracheal tubes through openings called spiracles on their abdomens Incomplete metamorphosis
How insects move and interact with humans • Pollinate plants • Bite or sting humans • Spreads diseases • Cause major plant damage • Honey
Lobster, crab, shrimp, barnacles, krill, brine shrimp • Have a cephalothorax (head and thorax combined) • Front claws for crushing and pinching • Walking legs • Swimmerets on the abdomen • Stalked eyes
ArthropodaChelicerata Greek Meaning – Jointed Foot Pincers Spiders, Horseshoe Scorpion Mites Ticks
Moving and Eating • Ambush and manipulate prey in web • Spinneretes – on abdomen, make webs • Scorpions – inject venom into prey • 8 jointed legs • Head and thorax fused
Human World • Painful stings (could be deadly) • Mites (feces causes allergies) and ticks (diseases like Lyme, Rocky Mt spotted fever) • Horseshoe crabs at beach is a sign of a healthy ecosystem • Spiders eat other insects
EchinodermataSpiny skinned animals Sea Star Sea cucumber Sand dollar Urchin Sea star eating a clam
Tube feetunder rays • Small hollow tubes • Create suction on the end • Used for food getting, respiration & movement • Connect to Water Vascular System -
Echinoderm systems • Respiration, Excretion & Circulation through tube feet • No Central Nervous system since no head! Nerve ring around the mouth with radial nerves leading off of it • Reproduction – Separate sexes and externally deposit eggs and sperm