BIOL 1108 Lecture 20: Chapter 44 Animal Evolution (Animal Diversity) Part 2
Document Summary
Cnidarians: coral, jellyfish, sea anemone - stinging thread : radial symmetry, diploblastic, tentacles have cnidocytes (stinging cells), around mouth for catching prey, blind gut (single mouth/anus), can have polyp stage, medusa stage, or both, solitary or colonial. Ctenophora: comb jelly: diploblastic and radially symmetrical like cnidaria, predators, catch prey with sticky tentacles that hang down under umbrella body, swim by beating rows of cilia. Bilaterians: all have bilateral symmetry and three germ layers. Protostomes - first mouth : spiral cleavage, determinate cleavage: cell fate is set in early embryo development, mouth pore forms first in the gastrula, mesoderm by schizocoely (not on test) Indeterminate cleavage: cell fate is set much later in the blastula (stem cells: anal pore opens first in the gastrula, mesoderm by enterocoely (not on. Lopho = lophophore: has tentacle lined (ciliated) organ for filter feeding: found in phoronida, bryozoa, brachiopoda. Trocho trochophore: a ciliated larval form: annelida, mollusca.
