BIOL 101 Lecture Notes - Lecture 13: Squid Giant Axon, Lipid Bilayer, Invertebrate
13 Jan 2016
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Document Summary
Which of the following statements about body cavities is. The coelom, when present, develops within the true? mesoderm. Variations on an ancestral molluscan body plan: mantle, visceral mass, mantle cavity (aquatic contains gills; terrestrial acts as lungs, radula (in mouth) Hinged shell (large adductor muscles to close it) Enlargement of foot (used as anchor & digging) Mantle (lined with eyes) cavity modified by siphons: Water flows in mantle cavity & across gills. Most diverse group of mollusks (~85,000 species) Cone snail modified radula into toxic harpoon. Can produce only sperm or eggs at any given time. Torsion: twisting of body (some dextral, some sinistral) Visual communication w/ color & texture (chromatophores) Mantle & siphon used for jet propulsion. Arms w/ suckers &/or hooks, some have 2 elongated tentacles. Females die after laying eggs or after eggs hatch. Regulate buoyancy w/ gases in chambered shell. Extinct at end of cretaceous (65 mya) Squid giant axon up to 1 mm in diameter.
