Biology Lecture ch 31 vocab

  1. cleavage
    the first few cell divisions of a zygote
  2. Cleavage patterns
    • many exist among animals
    • influenced by the configuration of the yolk
  3. radial cleavage
    • in echinoderms
    • yolk is evenly distributed through the egg's cytoplasm
    • "complete" cleavage
    • the fertilized egg is divided into an even pattern
  4. spiral cleavage
    • a permutation of radial cleavage
    • in lophotrochozoans
  5. diploblastic
    embryos that have 2 cell layers (ectoderm and endoderm)
  6. Triploblastic
    embryos that have 3 cell layers (ectoderm, mesoderm, and endoderm)
  7. Protosomes
    in the blastopore that the mouth forms first then anus
  8. Deuterostomes
    in the blastopore that the anus forms first then the mouth
  9. bilaterians
    • contains the groups protostomes and deuterostomes
    • have bilateral symmetry
  10. body plan
    the general structure, arrangement of organ systems, and function of its parts
  11. body cavity
    • the presence/structure of an internal, fluid filled space
    • based on acoelomates, coelomate, and psuedocoelomate
  12. acoelomate
    • non enclosed, fluid filled cavity
    • space filled with mesachyme
  13. psuedocoelomate
    • a fluid filled space in which organs are suspended
    • enclosed by muscles on the outside
    • lacks an inner layer around organs
  14. coelomate
    • contains a coelom
    • the body cavity develops within a mesoderm
    • has peritoneum lining the walls and organs
  15. hydrostatic skeleton
    • the cavities function as this most of the time
    • muscles move the fluid which moves the body parts
  16. segmentation
    • the division of animal's bodies into segments
    • this facilitates specialization of different body regions
    • allows animals to alter the shape of the body in complex ways
    • segments can move separately
  17. motile
    the ability to move from place to place
  18. sessile
    non moving, they stay in one place, usually attached
  19. filter feeders
    • animals that use a straining device to get food from the environment
    • water currents are essential for these
  20. choanocytes
    • specialized feeding cells
    • flagellated
    • help bring food towards them
  21. nematocysts
    • specialized cells containing stinging organelles
    • on tentacles
    • inject prey with toxins
  22. dispresal
    the movement of organisms from a parent organism or from existing populations
  23. trochophore
    a radially symmetrical larval form
  24. nauplius
    a bilaterally symmetrical larval form
  25. Bilateria
    • a large monophyletic group embracing all animals EXCEPT sponges, placozoans, ctenophores, and cnidarians
    • triploblastic
  26. eumatozoans
    everything not included in bilateria
  27. Sponges
    • simplest animals
    • no cell layers
    • no true organs
  28. Spicules
    • hard skeletal elements in sponges
    • can be large or small
  29. placozoans
    • simple animals
    • have few distinct cell types
    • asymmetrical
    • attach to surfaces
  30. ctenophores
    • "comb jellies"
    • radially symmetrical
    • diploblastic
    • >outer layer is the mesoglea
    • have beating cilia
    • >contain ctenes
  31. cnidarians
    • sea anemones, jellyfish, corals, and hydrozoans
    • has one opening for mouth/anus
    • has gastrovascular cavity
    • has 2 stages (motile and sessile)
    • motile-medusa
    • sessile-polyp
    • larvae is the planula
  32. gastrovascular cavity
    • a blind sac
    • functions in digestion, circulation, and gas exchange
    • acts as hydrostatic skeleton
  33. medusa
    • free swimming stage of the cnidarians
    • produced from budding of polyps
    • used for sexual reproduction
  34. polyp
    • the unmoving stage of cnidarians
    • attached to substratum
    • produce medusae by budding (asexual)
  35. planula
    • ciliated larval stage of the cnidarians
    • develops into polyps
    • formed from fertilized egg
  36. anthozoans
    • a clade
    • sea anemones
    • solitary
    • consists of 1+ polyps
    • polyps become specialized for feeding and reproducing
Card Set
Biology Lecture ch 31 vocab
Ch 31 vocab "Animal Origins and the Evolutionary Body Plans"