Echinoderms Test 3

  1. Fertilization is
    Union between egg and sperm
  2. Fertilization does what 2 things?
    • Recombination of genes and restores diploid status
    • Also causes the start of cleavage
  3. What is a small ball of cells called (egg)?
  4. Patterns of cleavage depends on?
    • Quantity and type of yold present
    • Type of symmetry inherited
  5. Isolethical yolk
    • Very little yolk
    • Evenly distributed in egg
  6. Holoblastic cleavage
    • Cells are surrounded by a membrane.
    • The cleavage furrow extends through the egg
  7. Telolecithal
    • Telos=end
    • Yolk is densly concentrated at the vegetal pole
    • Disc shaped mass on top of yolk mass=vegetal pole
  8. Radial cleavage
    • Pie-like characteristic of animals with backbones
    • AKA-regulative
  9. Indeterminate
    Cells of a blastomere are no identified as a specialty cell. If one cell is separated, it will form its own new blastomere.
  10. Symmetry of echinoderms and chordates
    radial symmetry
  11. Spiral cleavage
    Cleavage planes are oblique to the polar axis (animal/vegetal poles)
  12. Spiral cleavage
    Platyhelminthes, molluscs
  13. Blastula
    • Cluster of cells as a result of cleavage
    • Outer layer becomes ectoderm
  14. Gastrulation
    • Forms germ layers
    • New cell association occurs to body plan (specialized)
    • Invagination occurs-Deurterostomes, protostomes
  15. Ectoderm
    Epithelium of body and nervous system
  16. Mensoderm
    Muscles, reproductive, peritoneum
  17. Endoderm
    Epithelial lining of digestive tract
  18. Echinodermata includes and means?
    • External spines
    • Starfish, sea cucumbers, sea lilies, sand dollars
  19. Charcteristic of echinoderms
    • Spiny endoskeleton
    • Water-vascular system
    • Pericerllariae-Small pincers on the spine to remove debris
    • Dermal branchiae or papulae
    • Bilateral and pentaradial symmetry
  20. What is bilateral?
  21. Habitat?
    • Marine bottom dwellers
    • Not found in fresh or brakish waters
Card Set
Echinoderms Test 3
Echinoderms Test 3