BIOL 111 Lecture Notes - Pedicellaria, Pearlfish, Detritivore

• School: McGill University
• Department: Biology (Sci)
• Course: BIOL 111
• Professor: Multiple

Document Summary

November 6, 2007 head, segmentation, nervous system, anus, circulatory system, hard skeleton, coelom: know these and where they evolved for final exam. In protostomes: central nervous system is ventral, anus is from the second opening, circularoty system has a dorsal heart, hard skeleton is external, coelom develops from schizocoely. In deuterostomes: central nervous system is dorsal, anus is from the first opening, circulatory system has a ventral heart, hard skeleton is internal, coelom develops from enterocoely. Deuterostomes have radial cleavage but sometimes protostomes also have it. Deuterostomes: echinoderms, hemichordates, chordates (urochordates, cephalochordates, vertebrates) Ex: sea stars, sea urchins, sand dollars. Bio 111 alanna houston: continuous growth (plates enlarge and new ones are added, covered by thin layers of skin and muscle. Pentaradial symmetry (5-part symmetry) larvae have bilateral symmetry. Body plan: evolved from bilaterally symmetrical ancestor, anterior-posterior foreshortening, flopped over, mouth down o.