Chapter 33: Invertebrates (Part I)

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  1. Basal animals are also known as:
    Parazoans. Non-coelomate invertebrates
  2. What are two things that basal animals do not have?
    • Do not have tissues and organs
    • Do not have a definite symmetry
  3. Phylum Porifera aka...
  4. What is the major group of basal animals (parazoans)?
    Phylum Porifera (Sponges)
  5. How many species are in phylum Placozoa?
    • Only one
    • Trichoplax adhaerens
  6. Trichoplax adhaerens looks like a...
    • "hairy pita bread"
    • A bilayer of a few thousand cells
  7. How does Trichoplax Adhaerens reproduce?
    By dividing into two individuals or by budding off many multicellular individuals.
  8. 6 traits of Phylum Porifera:
    • 1. Marine AND freshwater
    • 2. Size ranges from a few mm to 2 meters in diameter
    • 3. Most asymmetrical... a few with radial symmetry
    • 4. Larval sponges are free swimming
    • 5. Adult sponges remain attached to substrate for the remainder of life
    • 6. Sponges defend themselves by producing chemicals that repel predators
  9. Sponges reproduce (sexually/asexually)
    Both! Sexually and asexually
  10. What is unique about larval sponges?
    They are free swimming
  11. How do sponges defend themselves?
    Producing chemicals that repel predators
  12. Phylum porifera (sponges) exist in what type of water environment?
    Both marine and freshwater.
  13. What is unique about the cells of a sponge?
    • If all the cells are separated, the cell types will seek each other out and reassemble the entire sponge.
    • No other animal can do this!
  14. In sponges, there are 8 types of cells with specialized functions (CAPPMOSS)...
    • 1. Choanocytes
    • 2. Amoebocytes
    • 3. Pinacodem
    • 4. Porocytes
    • 5. Mesohyl
    • 6. Osculum
    • 7. Spicules
    • 8. Spongin
  15. Specialized sponge cell type 1: choanocytes
    • collar cells
    • water circulation through sponge
    • capturing, engulfing, digesting food particles
  16. Specialized sponge cell type 2: Amoebocytes
    • Distribute nutrients through sponge
  17. Specialized sponge cell type 3: Pinacoderm
    • made of flattened cells
    • make up other epithelium
  18. Specialized sponge cell type 4: Porocytes
    flattened cells that line the pores of the ostia
  19. Specialized sponge cell type 5: Mesohyl
    • Gelatinous, protein-rich matrix
    • located between inner and outer cell layers
  20. Specialized sponge cell type 6: Osculum
    • Large openings where water exits the sponge
    • Osc= mouth
  21. Specialized sponge cell type 7: Spicules
    needlelike structures made of calcium carbonate or silica
  22. Specialized sponge cell type 8: Spongin
    tough protein fibers that make up the skeleton of some sponges
  23. Differentiate between ostia and oscula:
    • Ostia: where water enters the sponge
    • Oscula: where water exits the sponge
  24. In sponges, asexual reproduction occurs by...
  25. In sponges, sexual reproduction involves...
    fusion of sperm and egg
  26. Sponges are hermaphroditic, meaning...
    they have both male and female parts
  27. Parazoan vs Eumetazoa:
    • Parazoan: Animals without true tissue
    • Eumetazoa: Animals WITH true tissue
  28. True or false: All cnidarians are carnivores...
  29. Most of the 10,000 species of cnidarians are (marine/freshwater) but very few live in (marine/freshwater).
    • Most are marine
    • Few are freshwater
  30. Are cnidarians diplo or triploblastic? Why?
    • Diploblastic.
    • They have no mesoderm
  31. Cnidarians have (organs/tissue) but no (organs/tissue).
    • They have tissues
    • They do not have organs
  32. Which of the following systems does the cnidarian have?
    A. excretory
    B. digestive
    C. nervous
    D. circulatory
    E. reproductive
    C. nervous

    they have a nervous net
    (this multiple choice question has been scrambled)
  33. Nematocycts are unique to this phylum.
  34. What are the two body plans of cnidarians?
    • Polyp -- typically sessile
    • Medusa -- swims freely in water
    • Image Upload
  35. In both basic body plans of cnidarians, the mouth opens into a _____ and is surrounded by tentacles.
    GVC (Gastrovascular cavity)
  36. True or false: The GVC in cnidarians is a stomach.
    • FALSE! 
    • Cnidarians do not have ANY organs
  37. They two-layered body wall of cnidarians is made up of: ______ and _____.
    epidermis and gastrodermis
  38. What holds the epidermis and gastrodermis together in cnidarians?
    An acellular mesoglea-middle glue
  39. The GVC in cnidarians serves as a ______ skeleton.
  40. In cnidarians, polyps will sometimes build an exoskeleton of ____ or _____ _____ for extra support.
    chitin or calcium carbonate
  41. True or false: Sea anemones have no skeleton; neither do Medusae.
  42. Medusa forms are (solitary/colonial) while polyps can be (solitary/colonial).
    • Medusa -- Solitary
    • Polyps -- Colonial
  43. In the life cycle of cnidarians, some have...
    • 1. Polyps only
    • 2. Medusa only
    • 3. Both polyps and medusa (sexes are separate)
  44. Gonorchism
    • Refers to the life cycle of cnidarians having both polyp and medusa.
    • Both sexes are seperate
  45. The life cycle of cnidarians:
    Image Upload
  46. In some, but bot all species of cnidarian, the polyp can produce other polyps asexually by...?
    • Dividing 
    • Budding
    • Or breaking off bits that regenerate
  47. What is a major evolutionary innovation of cnidarians?
  48. Why can cnidarians take in larger prey items than a sponge?
    • Extracellular digestion of food inside the GVC.
    • Once partial digestion occurs in the GVC, other cells take up fppd fragments by phagocytosis.
  49. Namatocysts:
    microscopic stinging capsules
  50. What are some details about nematocysts?
    • capsule everts upon proper stimulation
    • Releases barbs (some have venom) that immobilize or kill prey
    • Only discharged once
  51. Cnidarians are grouped into four (or five) classes:
    • 1. Class Anthozoa-flowering animals
    • 2. Class Cubozoa-box jellies
    • 3. Class Hydrozoa-the hydroids
    • 4. Class Scyphozoa-cup animals
    • 5. Class Staurozoa-star jellies
  52. Cnidarian class #1: Anthozoa
    • "Flowering animals"
    • include sea anemones and corals that exist as solitary or colonial polyps
    • Form Coral Reefs
  53. Cnidarian class #2: Cubozoa
    • Box Jellies
    • medusa stage dominant (polyp reduced or unknown)
    • poison stronger than cobra venom
    • image-forming eyes
  54. Cnidarian class #3: Class Hydrozoa
    • The hydroids
    • both polyp and medusa stages in life
    • only class with freshwater members
    • some marine hydroids and medusae are bioluminescent
    • Portuguese man-of-war
  55. Cnidarian class #4: Scyphozoa
    • Jellyfish or "cup animals"
    • medusa more prominent and conspicuous
    • propel through ocean by jetting water from GVC
  56. Cnidarian class #5: Staurozoa
    • Star Jellies
    • Once included in class scyphozoa
    • resembles a medusa but is attached to substrate by a stalk like structure
    • Planula larva creeps rather than swims or drifts
  57. Phylum Ctenophora aka...
    Comb jellies (cteno = comb)
  58. Do ctenophora live in freshwater or ocean water?
    In the ocean, never freshwater
  59. 4 unique characteristics of Phylum Ctenophora:
    • 8 rows of combelike plates of fused cilia along two long retractable tentacles
    • colloblasts: cells that release strong adhesive
    • largest animal to use cilia for locomotion
    • many are bioluminescent
    • may be triploblastic and have bilateral symmetry
  60. This is the largest animal to use cilia for locomotion...
    Ctenophora (comb jellies)
  61. Bilatarian Acoelomates key feature:
    • Bilateral symmetry
    • functional specializations: anteriorly located nerve receptors
  62. Phylum Platyhelminthes aka...
    • Flatworms
    • (platy=flat + helminthe= worm)
  63. General traits of phylum platyhelminthes:
    • flattened and solid body (aside from incomplete digestive cavity)
    • free-living flatworms live in marine, freshwater, and moist terrestrial habitats
    • scavengers or carnivores
    • move with cilliated epithelial cells and well developed muscles
    • parasitic flatworms live inside bodies of other animals; rage from 1 mm to many meters.
  64. Digestion in flatworms:
    • incomplete gut that is branched
    • functions in both digestion AND distribution of food
  65. Excretion and Osmoregulation in platyhelminthes:
    • primary function of excretory system is water balance
    • waste diffuses into gut and expelled through the mouth
    • flame cells with "flickering" flagella move water and excretory substances
  66. What are flame cells and where are they found?
    • cells with "flickering" flagella that move water and excretory substances
    • Found in excretory system of platyhelminthes
  67. Nervous system and sensory organs of platyhelminthes:
    • anterior cerebral ganglion
    • nerve cords and cross connections that have ladder-like appearance
    • eye spots distinguish light from dark
  68. Platyhelminthe reproduction:
    • most are hemaphroditic
    • cross-fertilization is internal
    • can regenerate missing parts
  69. What are the 3 classes of Platyhelminthes?
    • 1. class Turbellaria (turbulant air=flame cells)
    • 2. Class Trematode: flukes
    • 3. Class Cestoda: tapeworms
  70. Platyhelminthe class 1: Turbellaria
    • "turbulent air=flame cells"
    • free-living flatworms such as Planarians
  71. Platyhelminthe class 2: Trematoda
    • Flukes
    • life cycle most often involves two or more hosts
    • many flukes cause disease in humans (schistomiasis - blood fluke)
  72. Explain the life cycle of Class Trematoda (flukes): 
    • involves two or more hosts
    • intermediate host usually snail
    • final host some type of vertebrate
    • Schistosomiasis--snail--humans
  73. Platyhelminthes class 3: Cestoda
    • tapeworms
    • no digestive cavity -- absorbs nutrients through outer surface from host's intestine
    • body portions: scolex, neck, proglottids
  74. Name the body portions of Platyhelminthes class Cestoda:
    • Scolex for attachment
    • neck
    • proglottids=repetitive sections that are largely reproductive
  75. Pseudocoelomates have a body cavity that lies between tissues derived from ____ and tissues derived from ____.
    • Endoderm
    • Mesoderm
  76. Pseudocoelom serves as _____ ______.
    Hydrostatic skeleton
  77. Phylum nematoda aka...
  78. General characteristics of Nematoda:
    • ecdysozoans that molt cuticles
    • 20,000 recognized species
    • marine and freshwater form
    • many are parasites of animals and plants
    • highly abundant in soil (millions)
  79. Explain the nematode structure:
    • Bilateral, unsegmented worm
    • flexible cuticle is molted as they grow
    • oxygen and carbon dioxide exchange occurs through cuticle
    • have longitudinal muscles, but NO circular muscles so can lengthen or shorten but can't change diameter.
  80. This type of worm has longitudinal muscles but no circular muscles.
    Roundworms (Nematoda)
  81. Traits of Nematode reproduction:
    • sexual reproduction
    • gonochoric (seperate sexes)
    • sexual dimorphism
    • internal fertilization
    • indirect development
  82. Gonochoric means...?
    Separate sexes (nematodes)
  83. Sexual dimorphism means...?
    Male and female look different
  84. Nematode lifestyles include the following...
    • hunters
    • parasites of plants or animals
  85. Nematode-caused human disease: Necator
    • found in southern states causes anemia
    • hookworms
  86. Nematode-caused human disease:Trichinella
    • causes trichinosis
    • mature worms form high resistant calcified cysts in muscle tissue
    • Don't eat raw pork or bear meat
  87. This disease is caused by eating raw or undercooked pork or bear meat.
  88. Nematode-caused human disease: Enterblus vermicularis
    • Pinworms
    • infect 30% of children and 16% of adults in the US.
    • Live in human rectum and cause itching
  89. Pinworms are caused by what type of nematode?
    Enterobius vermicularis
  90. Nematode-caused human disease: Ascaris lumbridoides
    • Infects 1 in 6 people worldwide
    • less common in areas of modern plumbing
    • Lives in human intestines
  91. Nematode-caused human disease: Wuchereria Bancrofti
    • filarial worms that cause elephantiasis
    • mainly seen in tropical areas
    • transmitted by an intermediate bloodsucking host such as mosquito
  92. This nematode causes elephantiasis.
    Wuchereria bancrofti
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Chapter 33: Invertebrates (Part I)
2013-11-02 23:16:41

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