[EEB267H1] - Final Exam Guide - Comprehensive Notes fot the exam (56 pages long!)
30 Mar 2017
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On a phylogenetic tree of the metazoa (multicellular animals), they are one branch: distant relatives: echinodermata (e. g. ,starfish), hemichordata (e. g. , acorn worms), xenocoelomorpha (marine) In the earthworm, the nerve cord runs along the belly: ventral nerve cord: function: forms the central nervous system spinal nerve cord and brain. Autapomorphy #3: the post-anal tail: function: movement (propulsion) At least 650 million years old based on fossils and molecular data) have not changed much, looks similar today. Approximately 35 species living in burrows in shallow, warm, coastal marine waters. The notochord runs to the anterior tip of the head. Small particles in the water are trapped in mucous surrounding the pharyngeal slits. Many molecular characteristics, including some genes involved in olfaction. Has a type of mechanoreceptor: sensory hair cells: able to detect movement of water; eventually moves into the ear to detect sound waves. Over 3000 species, all marine some colonial and some solitary.
