BIO 200 Lecture Notes - Lecture 19: Nematomorpha, Jet Propulsion, Mollusca
28 Oct 2016
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Lophotrochozoans: part two: annelids, mollusks are highly diverse, mollusk body plan, mollusk reproduction, there are four classes of mollusks. Ecdysozoans: what is an ecdysozoan, horsehair worms and nematodes, velvet worms and water bears, arthropods. Coelomates have a coelom lined with muscular tissue (mesoderm) Segmentation allows for specialization: reproduction, digestion, excretion, feeding, respiration, locomotion. Annelid segments are a stack of hollow rings. The sensory organs are in the anterior segments. There are two classes of annelids: earthworms and leeches, polychaetes. Mollusks have a three-part body plan: foot: used for a variety of purposes, visceral mass: holds the organs, mantle: covers the dorsal portion of all mollusks. There are variable levels of cephalization in mollusks. Mollusks have a specialized mouthpart called the radula. Tentacles common (eyes and chemo- or mechanosensing. Cephalopoda: octopus, squid, and nautilus (about 800 species) Horsehair worms are very different as larvae and adults. Also molt: elegans a model organism. Fixed number of cells: 959 cells.
