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Ch 7 animalbio
| Question | Answer |
|---|---|
| PHYLUM: More complex than sponges but simple; sessile or feebly-swimming, effective predators | Cnidaria |
| Contain the animals stinging organelles (cnidae) | Cnidocytes |
| Longest fossil history | Cnidaria |
| Ctenophores and Cnidaria are characterized by: | primary radial symmetry: good for sessile animals because they approach environment from all sides equally |
| These phylums are only up to this level of organization | tissue level organization with few organs |
| Adults only have epidermis and gastrodermis, developed from two embryonic layers (ectoderm & endoderm) | Diploblastic |
| Why can they not produce true muscles | Because muscles come from mesoderm |
| One jellyfish found in Ohio (freshwater) | C. Sowerbyi |
| Bioluminescent crystal jelly; hydrozoan medusa found off west coast of North America | Aequorea victoria |
| protein first isolated from the crystal jelly, used a reporter of gene expression; proof-of-concept that a gene can be expressed thru out a given organism | GFP (green flourescent protein) |
| CLASS: mostly marine; cnidocytes in epidermis, no wandering mesechyme cels, medusa (if present) with a velum, colonial polyps. Some may be medusa only. | Hydrozoa |
| CLASS: all maria, medusa prominent life stage, small polyps, epidermis and gastrodermis, no velum, wandering mesenchyme cells, manubirum for food capture and ingestion | Scyphozoa (true jellyfish) |
| CLASS: medusa attached to polyp, octamerous body plan, nonswimming larva | Staurazoa |
| CLASS: cuboidal medusa, tentacles from each corner, square and active swimmers. Velarium present, neurally advanced. | Cubozoa (eg. sea wasp) |
| CLASS: all marine, polyp only, occur at all depths, cnidocytes in gastrodermis, cavities divided by mesenteries, mesoglea with wandering mesenchyme cells | Anthozoa (anenomes, stony and soft corals) |
| mouth opens to this region which extends into the tentacles and may be fused in colonial hydroids (nutritive, muscular, interstitial, gland cells and cnidocytes (except hydrozoa). | Gastrovascular cavity |
| Primary support of Cnidarians is through a | hydrostatic skeleton |
| Forms the body wall; epitheliomuscual cells, interstitial cells, gland cells, cnidocyts, sensory and nerve cells. | Epidermis |
| A layer of large, ciliated columnar epitelial cells that may contain large numbers of food vacuoles | Gastrodermis |
| Gelantious with elastic cells, but may have amoeboid cells and epitheliomuscular cells; thicker in medusa; between epidermis and gastrodermis | Mesoglea |
| Forms most of the epidermis and serve for covering and for muscular contraction ability | Epitheliomuscualr cells |
| Tissue that forms as striated muscle from ectoderm, while the inner wall forms the smooth muscle of the feeding and sex organs | Entocodon |
| Cells abundant around the mouth and in the pedal disc of hydra, secrete mucus or adhesive material | Gland cells |
| Cells scattered among other epidermal cells, around mouth and tentacles especially. Free end bears flagellum which is sensory receptor while other end reacts with nerve cells | Sensory cells |
| Undifferentiated stem cells found among bases of epitheliomuscular cells, producing other cells | Interstitial cells |
| Sensory signals are passed by flagellated cells that pick up tactile or chemical cues; vesicles may occur on both sides allowing two way communication | Nerve net (no central nervous system) |
| Stinging cells of Cnidarians | Cnidocytes |
| Where do cnidocytes arise from | Epidermal Interestial Cells |
| They possess this form in which they alternate between a free swimming medusa and a sessile polyp stage (except staurazoa medusa attached to polyp, anthozoa only poylp, and some hydrozoa) | Dimorphism |
| Cnidarians divide functions among polyps; thus | polyps are identical so it does not matter which reproduce, defend the colony, or gather food |
| Atypical hydrozoan that have no medusa at all | Hydras |
| Medusas have which kind of symmetry | Tetramerous |
| A modified cilia, sensory structure which induces discharge of hollow tube which either have a paralyzing toxin or wrap around prey | Cnidocil |
| The nematocyst is emitted via | high osmotic pressure |
| Polyps and medusa are both | diploid; asexual and sexual reproduction |
| This class has a STATOCYST for balance, two sensory pits, and ocelli (simple eyes) | Scyphozoa |
| Cubozoa have four, flattened, blade-like structures from which the tentacles are suspended | Pedalia |
| Cubozoa have these, which are complex and may include eyes with lenses to help in their predatory lifestyle | rhopalia |
| CLASS: Medusa-like structure remains attached allowing polyp to reproduce sexually | Staurozoa |
| CLASS: Flower-like appearance and no medusa stage occurs | Anthozoa |
| How do Anthozoans differ from Hydrozoans | Mouth opens to pharynx and a ciliated track (siphonoglyph) moves water down the gastrovascular cavity. The gastrovascular cavity is divided by mesenteries that bear nematocysts (no cnidocils), and internal symmetry is biradial. |
| The hard or stony corals | Zoantharian corals (Coral Reef) |
| The marine diversity hotspot | Ecosystem |
| Tube anemones and thorny corals with a hexamerous body plan | Ceriantipatharia |
| Soft and horny corals, sea fans, sea pets with an octamerous body plan | Octocorallia |
| Comb jelly; dipoloblastic with true muscles, biradial symmetry; gelatinous mesoglia between epidermis and gastrodermis; presence of nerve net | Ctenophore |
| Due to ctenophores 8 comb rows of ciliated bands they are | largest animals which swim by cilia |
| Specialized glue cells of Ctenophore tentacles | colloblasts |
| Class: Flourescent | Tentaculata |
| No tentacles, flattened, branched gastro cavity with eats other jellyfish | Beroe |
| Introduced species in the black sea region that eats larval fish and crustaceans | Mnemiopsis leidyi |
| Unusual ctenophore; venus girdle | Cestum veneris |