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2015-03-06 08:24:11
Unit1 Bio
Unit 1, lectures 7-9
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  1. What are metazoans?
  2. Characteristics of metazoans?
    Multicellular, heterotrophs (ingest food), true tissue, lack cell walls, structural proteins
  3. What are invertebrates?
    Animals that lack a backbone
  4. What distinguishes sponges from the majority of animals?
    Sponges do not have true tissue, but animals do
  5. What are animals that have “true tissue” called?
  6. How can sponges be described sexually?
    They are hermaphrodites, meaning they produce both sperm and eggs
  7. Describe the structure of a sponge:
    • epidermal cells surround outside
    • pores are made to allow water to flow through and to collect food
  8. What kind of feeders are sponges?
    Suspension/filter feeders, wait for food to come to them
  9. What is the spongocoel?
    a cavity in the sponge through which water enters
  10. What lines the interior of the spongocoel in sponges?
    Flagellated choanocytes, which beat their flagella to create a water current
  11. What are choanoflagellates? Why are they important?
    • they are single-celled, colony forming eukaryotes that look very similar to choanocytes
    • Important because they are thought to be the oldest living relative of animals
  12. What is the purpose of choanoflagellates?
    • trapping food particles, primarily bacteria through phagocytosis
    • can also form colonies where cells are clustered together, can attach themselves to stalk
  13. How do cnidarians differ from sponges?
    They are eumatozoans ( have true tissue), sponges are not
  14. What are tissues?
    Collections of specialized cells isolated from other tissues by membranous layers
  15. What are the two kinds of forms a cnidarian may have?
    • Polyp (mouth up, sessile)
    • Medusa (mouth down, motile)
  16. What are the tentacles of cnidarians lined with?
    cnidocytes, which function in defense and prey capture
  17. How many germ layers are present in Cnidarians?
    two (diploblastic) — epidermis and gastrodermis
  18. What kind of body plan do cnidarians have?
  19. What is cephalization?
    The development of a head
  20. How many germ layers do bilaterians have?
    three (triploblastic)
  21. What is the ectoderm?
    germ layer covering the embryo’s surface
  22. What is the endoderm?
    innermost germ layer, lines the digestive tube as well
  23. What is the mesoderm?
    the middle layer, in-between endoderm and ectoderm
  24. What is a coelom?
    a true body cavity
  25. What do most triploblastic animals possess?
    a body cavity
  26. What are coelomates?
    animals that possess a true coelom
  27. What are the 6 phyla of lophotrochozoans?
    • 1. Flatworms
    • 2. Rotifers
    • 3. Ectoprocts
    • 4. Brachiopods
    • 5. Molluscs
    • 6. Annelids
  28. Why do flatworms not have any specialized organs for gas exchange?
    Because all of their cells are close to the water, since they are flattened
  29. What are two type of flatworms?
    Planarians and Tapeworms
  30. Why are flatworms called acoelomates?
    Because they lack a body cavity between digestive tract and outer body wall
  31. What group can ectoprocts and brachopods be put into together?
  32. Describe structure of planarians: (how many openings, sexual lifestyle, how they move)
    • Gastrovascular cavity with one opening
    • Hermaphrodites, Asexual reproduction through fission and regeneration
    • Move by using cilia on their ventral surface
    • Light sensitive eye spots and nerve nets
  33. What kind of relationship do tapeworms have with vertebrates?
  34. Why do tapeworms absorb nutrients from host’s intestine?
    Because they lack a digestive system
  35. How do tapeworms reproduce?
  36. How are rotifers different from cnidarians and flatworms?
    Rotifers have an alimentary canal (two openings) while cnidarians/flatworms have a gastrovascular cavity (one opening)
  37. What is a psuedocoelomate? Which animals belong in this category?
    • Animal with a body cavity that is not completely lined by mesoderm
    • Rotifers
  38. What is an alimentary canal?
    A digestive tube with two openings (mouth and anus)
  39. What do ectoprocts resemble?
    Clumps of moss
  40. What do brachiopods resemble?
  41. What is another name for annelids?
    Segmented worms
  42. What are the three classes of annelids?
    Oligochaetes, Polychaetes, Leeches
  43. How are the three classes of annelids?
    by type of chaete (bristles made of chitin)
  44. What kind of coelom do annelids possess?
    True coelom, known as coelomates
  45. Describe oligochaetes (amount of bristles, presence or absence of parapodia)
    • few bristles
    • no parapodia
    • reduced head
  46. Describe polychaetes (amount of bristles, presence or absence of parapodia)
    • many bristles
    • parapodia
    • well developed head
  47. Describe leeches
    • no bristles
    • reduced segmentation
    • parasites and predators
  48. How are nematodes and planarians similar?
    they both lack a circulatory system
  49. What are the advantages to using C.Elegans in research?
    • their transparent body is good for microscopy
    • can be frozen for long-term storage
    • simple nervous sytem
  50. What does to mean to be an arthropod?
    to have jointed feet
  51. Describe anatomy of an earthworm
    • internal structures repeated within each segment
    • closed circulatory system
    • 2 openings, mouth and anus
    • hermaphrodites, cross-fertilize
  52. What are mollusks?
    soft-bodied animals, most are protected by a hard shell
  53. What do mollusks use to feed?
    radula, helps them scrape food
  54. What is the basic body plan of a mollusk?
    • foot— for movement
    • visceral mass— contains most of organs
    • mantle— secretes shell, covers visceral mass
  55. What are the 4 classes of mollusks?
    chitons, gastropods, bivalves, cephalopods
  56. What are chitons? (head?, body shape?)
    • a class of mollusks
    • oval shaped body
    • shell with 8 plates
    • no head
  57. What is a gastropod? (head?, how do they move?, shell?)
    • a class of mollusks
    • has a distinct head with eyes
    • move slowly with their cilia
    • protected by a spiraled shell
  58. What are bivalves? (kind of feeders?, where do they live?, head?, coelom?, shell?)
    • a class of mollusks
    • suspension feeders, sedentary
    • all aquatic
    • no distinct head or radula
    • have a coelom
    • shell is present
  59. What are cephalopods? (head?, shell?, organs?)
    • a class of mollusks
    • active marine predators (tentacles)
    • distinct head with eyes
    • well developed organs and brain
    • closed circulatory system
    • shell is reduced or internal
  60. What is special about ecdysozoans?
    they have a cuticle (tough coat that covers body)
  61. What is molting?
    when the cuticle is shed and new one takes its place
  62. What are the two types of ecdysozoans?
    Nematodes and Arthropods
  63. What kind of ecdysozoan is a C. Elegan?
  64. Characteristics of nematodes?
    • roundworms
    • non-segmented
    • pseudocoelomates
    • lack circulatory system
  65. Characteristics of arthropods?
    • hard exoskeleton
    • joined appendages
    • segmented coelomates
  66. When did arthropods originate?
    • early paleozoic era
    • due to cambrian explosion
  67. What is a cephalothorax?
    head fused with thorax
  68. What are the 4 subphyla of arthropods?
    Chelicerates, myriapods, hexapods, crustaceans
  69. Describe anatomy of a chelicerate
    • two-part body
    • abdomen and cephalothorax
  70. When did the first chordates appear?
    During the cambrian period
  71. 3 ways to distinguish deuterosomes from ecdysozoans?
    • radial cleavage of fertilized egg
    • anus develops from blastopore
    • mesoderm splits into two pieces
  72. What is a blastopore?
    indentation formed during gastrulation
  73. What does it mean if a cell is indeterminate?
    cell retains capacity to develop a complete embryo
  74. When/what period insects originate?
    Devonian Period of Paleozoic era
  75. What are the main body parts of arthropods
    cephalothorax, abdomen, antennae
  76. What are chelicerae?
    claw-like feeding appendages (pincers or fangs)
  77. What is the basic body plan of arachnids?
    four pairs of legs, chelicera, pedipalp
  78. What is the basic body plan of an insect?
    Head, thorax, abdomen
  79. What is incomplete metamorphosis?
    When young resemble adults but are smaller and lack wings
  80. What is complete metamorphosis?
    when larval stage looks entirely different from adult stage
  81. Characteristics of echinoderms?
    • slow-moving, sessile
    • water vascular system
    • separate males and females
  82. What is special about the symmetry of echinoderms?
    Adults have radial symmetry, but larva have bilateral symmetry
  83. What are the five classes of echinoderms?
    • Sea stars
    • Brittle stars
    • Sea urchins
    • Feather stars
    • Sea cucumbers
  84. Describe the water vascular system of a sea star
    • network of hydraulic canals for feeding, movement, and gas exchange
    • Ring canal in center, plus 5 radial canals (one for each arm)
  85. What are vertebrae?
    series of bones that make up vertebral column (backbone)
  86. What is the purpose of the notochord in chordates?
    skeletal support
  87. Basic body plan of chordates?
    Notochord, nerve chord, digestive tube, post-anal tail, pharyngeal slits
  88. What are cephalochordates?
    Chordates with a brain
  89. What are craniates?
    Chordates with a cranium/skull
  90. What are jaws?
    hinged structures with teeth
  91. What are the three modes of embryo development?
    • oviparous: eggs hatch outside mothers body (fertilized internally or externally)
    • ovoviparous: embryo develops within mothers body
    • viviparous: embryo develops within mother’s uterus, nourished through yolk sac placenta from mothers blood
  92. When did the transition to land take place? What era?
    Plaeozoic Era
  93. When did reptiles originate?
    Carboniferous period, mid to late Paleozoic Era
  94. With which organism did the vertebral column evolve?