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BI 101: Invertebrate Animals

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BI 101: Invertebrate Animals 12/4/2013 BI 101: Invertebrate Animals Announcements • Lab tomorrow: Invertebrates ( lab worksheet provided) – 8 am start – No prelab • Holiday: No class Friday! 1 12/4/2013 Classification The three-domains Bacteria Archaea Eukarya The six-kingdom system Bacteria Archaea Protista Plantae Fungi Animalia The traditional five-kingdom system Monera Protista Plantae Fungi Animalia (Forams and Radiolarians) Rhizarians Alveolates Rhodophyta Stramenopile CHLOROPHYTA Euglenozoa AMOEBOZOANS 2 12/4/2013 What are some characteristics animals share? List as many as you can think of. Discuss this in your groups Animal Cell Fungus Cell 3 12/4/2013 Evidence indicates that animals evolved from choanoflagellates (protists) ~ 570 mya • Single cells • Often clonal • Heterotroph • No specialization or coodination between cells Animal Classification 1. DNA sequencing 2. Body Symmetry 3. Presence or absence of body cavity 4. Embyonic Development 4 12/4/2013 Symmetry Body Cavity Most bilateral animals have body cavities – Body cavities are fluid-filled cavities between the digestive tube and the outer body wall – Functions: • skeleton, providing support for the body and a framework against which muscles can act • protective buffer between the internal organs and the outside world • They can allow organs to move independently of the body wall 5 12/4/2013 Body Cavity? epidermis gut cavity organs packed between A No coelom gut and body wall (acoelomate animal) Fig. 25-4a, p. 405 Body Cavity? epidermis gut cavity B Pseudocoel (pseudocoelomate animal) unlined body cavity around gut Fig. 25-4b, p. 405 6 12/4/2013 Body Cavity? gut epidermis cavity C Coelom body cavity with a lining (dark (coelomate animal) blue) derived from mesoderm Fig. 25-4c, p. 405 Embryonic Development Blastopore forms Protostomes mouth first Deuterostomes Blastopore forms anus first 7 12/4/2013 What is the difference between vertebrates and invertebrates? 8 12/4/2013 Porifora - sponges • Sessile (Larva motile) • No true tissues or organs • Exhibit asymmetry or radial symmetry • Filter feeders (water flow out Sponge Anatomy of the sponge) epithelial cell pore spicules (water flow into the sponge) amoeboid cell pore cell collar cell (water flow) Fig. 23-5 9 12/4/2013 Sponge filtration/feeding Collar Cell Collar Cell http://www.youtube.com/ watch?v=T7E1rq7zHLc&feat ure=player_embedded http://www.youtube.com/watch?v =29W77870BgE&list=PLVN5247pO BYcE1Mn_pWHIL9l0sMIx19TI Sponges for Breast Cancer Research! • The artificial component called eribulin mesylate imitates an element found in sponges. • It can check cell division, which is a reason of cells to self-damage. • http://www.topnews.com.sg/content/22106-marine- sponge-probable-treatment-breast-cancer 10 12/4/2013 Cnidaria – Sea Anemone • Radial symmetry • Two tissue layers • Filled with water– supports body • Nerve net • Nematocysts -stinging organelles that release toxins 11 12/4/2013 Cnidarian Weaponry: The Cnidocyte trigger filament trigger nuclei (b) Cnidocytes Fig. 23-8 Cnidaria: Symbiosis Coral is a mutualism between photosynthetic dinoflagellates (protist) and a cniderian (animal) • Algae in coral called zooxanthelle 12 12/4/2013 In many coral species polyps form colonies Cnideria video Colonial polyps secrete a hard external skeleton of calcium carbonate The skeleton remains after the polyp dies New polyps build on the skeletal remnants of earlier generations 13 12/4/2013 Platyhelminthes - flatworms • Bilateral symmetry • 3 tissue layers • Cephalization (nerve mass) • True organs and organ systems • Aceolomate (no body cavity) • Parasitic forms but some free living 14 12/4/2013 Announcements • Quiz 7 today • Final exam next Monday • 8-10am (longer if needed) • Study both Midterm & Final study guide • Study groups encouraged! Evolved ~500 mya 15 12/4/2013 Mollusca Characteristics: • bilateral symmetry • Coelomates- true body cavity • Unsegmented • aquatic & terrestrial • possess all organ systems Mollusca Diversity 2nd most diverse animal group: 93,000 species Gastropods Cephalopods Bivalves 80% of mollusk Most neurologically Aquatic species advanced • Clams • Snails Marine predators • Mussels • Slugs • Octopus • Nudibranchs • Squid • Cuttlefish 16 12/4/2013 Nudibranchs • 3,000 described species • Snails without a shell • Unique lifestyle and defense mechanisms Elysia– the photosynthetic animal (video) Glaucus atlanticus consumes ‘man of war’ jellyfish and puts the nematocytes on its own back! Nudibranchs The Blue Dragon, Pteraeolidia ianthina, has a symbiosis with dinoflagellates. It also steals the armed tentacles of a sea anemone, a Cniderian, for defense and combat! 17 12/4/2013 Annelida - segmented worms Fig. 32-8 Coelom Body covering • Segmented body (from ectoderm) • Bilateral symmetry Tissue layer lining coelom • 3 tissue layers Digestive tract and suspending (from endoderm) internal organs • Coelom (fully enclosed (from mesoderm) body cavity) (a) Coelomate Body covering • Organ systems are more (from ectoderm) fully developed Pseudocoelom Muscle layer (from mesoderm) • Decomposers and Digestive tract (from endoderm) Parasites (b) Pseudocoelomate Body covering (from ectoderm) Tissue- filled region (from mesoderm) Wall of digestive cavity (from endoderm) 18 (c) Acoelomate 12/4/2013 Annelida - segmented worms • Class: Polychaetes – Each segment with many hairlike chetae – 12,000 species – Mostly marine • Class: Clitellata – Earthworms - Oligochaete 10,000 species Terrestrial Decomposers – Leeches – Hirudinea 700 species Predators or parasites Most freshwater Discussion questions 1. How do earthworms differ from tapeworms and planarians? 19 12/4/2013 Fig. 32-8 Nematoda - Round worms Coelom Body covering • Exoskeleton (molts)– 25,000 (fromspecies ectoderm) body coved in a thick Tissue layer cuticle lining coelom Digestive tract and suspending • Psuedocoelom (false (from endoderm) internal organs (from mesoderm) body cavity) • Bilateral worms (a) Coelomate • 3 tissue layers Body covering • Unsegmented (from ectoderm) Pseudocoelom Muscle layer • Parasitic (50%) (from and free-living (50%) mesoderm) Digestive tract (from endoderm) (b) Pseudocoelomate Body covering (from ectoderm) Tissue- filled region (from 20 mesoderm) Wall of digestive cavity (from endoderm) (c) Acoelomate 12/4/2013 A Freshwater Nematode posterior end intestine anterior end ovary vagina eggs mouth cuticle Fig. 23-25 Discussion questions 1. How do earthworms differ from tapeworms and planarians? 2. How do earthworms differ from nematodes? 21 12/4/2013 Arthropoda– Earth’s most diverse phylum Billions of species! Major groups: • Crustaceans • Myriopods • Arachnids • Hexapods 22 12/4/2013 Arthropoda Characteristics 1. Exoskeleton= External skeleton 2. Specialized body segments 3. Jointed appendages 4. Bilateral symmetry 5. True coelom (body cavity) Arthropoda respiratory system: Trachea 23 12/4/2013 Arthropoda respiratory system: Example: Grasshopper • Spiracles: pores in exoskeleton • Trachea: connect to spiracles, carry oxygen to the body cells Arthropoda respiratory system 24 12/4/2013 Arthropod Phylogeny Chelicerata 8 legs • Arachnids – spiders, – Mites – Ticks – scorpions • Horseshoe crabs • Pseudoscorpians 25 12/4/2013 Arthropod Phylogeny Crustaceans Rolly pollies– Isopods Lobsters Crayfish Crabs Shrimp Krill Baracles 26 12/4/2013 Arthropod Phylogeny Myripoda • Class: Symphyta • Class: Chilopoda (centipedes) • Class: Diplopoda (millipeds) 27 12/4/2013 Arthropod Phylogeny Diplura Insecta Protura Collembola Hexapoda: Reduction in body segments to 3 Reduction in legs to 6 Arthropod Phylogeny Thysanaura : Slverfish Archaegnatha Diplura Protura Collembola Wings! Insecta: mouthparts outside head capsule Hexapoda: Reduction in body segments to 3 Reduction in legs to 6 28 12/4/2013 Figure 23-19 Segments are fused and specialized in insects antennae head thorax abdomen compound eye mouth parts wing Specializations for Feeding Grasshoppers (a) – mouth has numerous manipulating and shearing parts for eating vegetation. Flies (b) – has a labium mouth part that has a sponge like end for absorbing nutrients from moist foods. Butterflies & Moths (c) – mouth part is a tube like maxilla for sucking up nectar from flowers. Mosquitoes (d) – have a stylus for piercing their prey to draw blood like a hypodermic needle. 29 12/4/2013 Insect Development Discussion Why might it be advantageous for insects to have complete metamorphosis? 30 12/4/2013 31 12/4/2013 Phylum Echinodermata 6,000 species Includes sand dollars, sea urchins, sea stars, sea cucumbers, and sea lilies Three tissue layers True coelom Echinodermata characteristics 1. Deuterostomes 32 12/4/2013 Echinodermata characteristics 2. Larvae exhibit bilateral symmetry; adults show radial symmetry Echinodermata characteristics 3. Endoskeleton (internal skeleton) that sends projections through the skin Composed of calcareous plates or ossicles 33 12/4/2013 Echinodermata characteristics 4. Water vascular system: Food and waste transport Respiration Locomotion Discussion question • How do sea urchins and sea stars differ from sea anemones and coral? VS 34 12/4/2013 Animal Diversity Ancestral Derived Radial Symmetry Bilateral 0, 2 # of tissue layers 3 1 # gut openings 2 Acoelomate, Type of coelom Eucoelomate Pseudocoelomate Type of development Protostome Deuterostome 35 .
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