BIOL 1902 Lecture Notes - Lecture 10: Cedar Waxwing, Abies Balsamea, Ruffed Grouse
24 Mar 2016
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Document Summary
Digestion: hard to digest due to tough structural components. Slugs & snails break off plant tissues w/ radula (chainsaw-like feature) Caterpillars have modified mandibles: some eat leaves from the inside. Mammals use modified teeth: beavers & squirrels" teeth are orange b/c they are full of iron, incisors never stop growing & self-sharpen. Moose only have lower incisors, so they rip off plant tissues. Large cheek teeth grind up food powered by large masseters. Mandibles, radula & cheek teeth all perform the same function, but arise from different origins: analogous structures, ruffed grouse have no teeth. Bite off swelling buds on trees: spruce grouse eat conifer needles, analogous to the radula, mandibles & cheek teeth is the gizzard (grinds & turns food; ingestion & digestion) Caterpillars don"t produce enzymes they waste a lot: they eat 10x their body weight every day. Moose get help from bacteria: chew cud (comes from stomach) rumen, food processed twice: rumination, symbiotic relationship.
