Animals

• Probe: Hydra retracts tentacles; muscle fibers & nerve net.
• Nematocyst: Mechanical or chemical stimulation causes Cnidocytes to inject toxin into prey, paralyzing them, then using tentacles to capture into gastrovascular cavity for digestion.
• Acetic Acid: Stimulate Hydra nematocyst; proves hydra food sense and nervous system.
• Are tapeworm and fluke coelomates? Why or why not?

  Flukes and tapeworms are acoelomates because they are parasitic, and so do not need developed digestive systems, because they get all their nutrients from their hosts.
• Annelids: Bilateral; coelomates; ganglia head; closed circulatory system; no distinct heads; no jointed appendages; no exoskeletons.
• Endotherms: Birds, mammals; regulate body temp; can live in whatever habitat; more energy.
• Explain how pillbugs respond to dry vs wet environment. Explain the difference. Explain whether this is a tactic response or a kinetic response.

  Pillbugs display positive taxis in moving towards the moist environment. This is a tactic response because it is directional, as opposed to kinetic which is not.
• Where is the natural habitat of pill bugs?

  Pillbugs reside in damp environments, commonly found close to the ground; under leaf piles, logs, and composts. For this reason, they demonstrated preference for dark and moist environments in lab.
• What features of flat worm distinguish its head from its tail?

  Flatworms are bilaterally symmetrical, meaning they display cephalization, and so have concentrated nerve bundles in the head region. Flatworms also have eyespots and auricles with chemoreceptors which are located in the head region.
• Does the planaria move toward or away from the light?

  Planaria move away from the light, meaning they exhibit negative phototaxis.
• Taxis: Directional response to a stimulus.
• Kinesis: Non-directional response to a stimulus. Pillbugs.
• Innate Behavior: Behavior that does not require learning or environmental input.
• Learned Behavior: Behavior that is acquired or modified later in life by various experiences.
• Orientation Behavior: Behaviors exhibited in response to a stimulus such as moisture, light, temperature, and chemicals.
• Cnidarians: Radial symmetry; diploblastic, two cell layers, ectoderm, mesoglea, endoderm; polyp, medusa; muscle fibers; nerve net; gastrovascular cavity; cnidocytes; nematocyst; anthozoans, scyphozoans, hydrozoans.
• Cnidarian Polyp: Vase; tentacles up; attached to substratum; asexual, budding.
• Cnidarian Medusa: Umbrella; tentacles down; free-swimming; release sperm into water; produce planulae.
• Anthozoans: Polyp; corals, sea anemones.
• Scyphozoans: Polyp, medusa; medusa dominant; jellyfish.
• Hydrozoans: Polyp, medusa; polyp dominant; colonial specialized polyps; most diverse group; sessile obelia; hydra polyp; portuguese man-of-war.
• Hydrozoan Specialized Polyps: Gonozooids, gastrozooids, dactylozooids.
• Sponges: Asymmetrical; ostia pores; osculum opening; water cavity spongocoel; choanocytes flagella move water; spicules.
• Planaria: Freshwater; free-living; flatworm; dorsoventrally flattened; bilateral symmetry; triploblastic; acoelomate; mesoderm surrounds body cavity; mouth; pharynx; branched gut; no anus; eyespots; auricles, chemoreceptors; hermaphroditic; also asexual; negative phototaxis.
• Earthworms: Triploblastic; bilateral symmetry; cephalization; pharynx; esophagus; crop; gizzard grinding; intestine, in-fold, typhlosole; closed circulatory system; tubular hearts; hermaphrodites; clitellum mucus sex; segmented; coelmate; hydrostatic, longitudinal, circular muscles; setae; blastospore.
• Mollusks: Bilateral; foot, mantle; visceral mass; gills; coelomate; chitons, bivalves, gastropods, cephalopods.
• Chitons: Oval body; shell 8 segmented calcareous plates; sessile, rock, foot; scrape algae, radula; gills.
• Bivalves: 2 part hinged shell; wedge foot; mantle; excurrent, incurrent siphon; gills; filter feeders; cilia; mussels, clams, scallops, oysters.
• Gastropods: Highly diverse; aquatic, terrestrial; large, flat, foot; some one-part spiral-shaped shell; some no shells, slugs.
• Cephalopods: Mantle, surrounding visceral mass, longitudinal, circular, collar, siphon; carnivores; foot is arms, suckers, some tentacles; beak; siphon, jet propulsion; closed circulatory system; chromatophores, pigments; ink sac.
• Squids: 8 arms, suckers; 2 tentacles, longer, suckers end.
• Arthropods: Segmented bodies; jointed appendages; exoskeletons, chitin, calcium carbonate; crustaceans, hexapods, chelicerates, myriapods.
• Crustaceans: Head, thorax, abdomen; head segments fused; abdomen 5 pairs swimmerets, oxygen, sex; tail, telson, uropods; crayfish.
• Insects: Head, thorax, abdomen; thorax three pairs legs; spiracles air, tracheoles; exoskeleton; grasshopper.
• Chelicerates: Cephalothorax, abdomen; cephalothorax jointed appendages, chelicerae; spiders, myriapods, centipedes.
• Deuterostomes: Bilateral; blastopore anus; echinoderms, hemichordates, chordates.
• Echinoderms: Larva bilateral; adults pentaradial; internal calcareous plates; madreporite, ring canal, radial canals, ampulla; sea cucumber, sand dollar, sea urchin, sea star.
• Sea Stars: Carnivore; tube feet open food bivalve, releases stomach, brings digested food back; nerve ring, radiating nerves.
• Chordates: Pharyngeal slits, dorsal nerve cord, notochord, post-anal tail; lancelets, tunicates, vertebrates.
• Lancelets: Notochord, dorsal nerve cord, pharyngeal slits, post-anal tail throughout life.