BIO 112 Lecture Notes - Lecture 11: Box Jellyfish, Gastrodermis, Nerve Net
16 Nov 2016
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All a(cid:374)i(cid:373)als share the (cid:272)lade (cid:862)metazoa(cid:863), eu(cid:373)etazoa bilateria - all are triploblastic and have bilateral symmetry lophotrochodoans shed skin and have sponges and cnidarians. Mesocytes- muscle cells sponges acquire and use oxygen sense and respond to the environment sponge release larvae that are able to move and place themselves somewhere. Hermaphrodite / take turns being male and female. Sponges have collagen sponges do not have hox genes, and do not have muscles sponges have toxins that are used for medicines for humans (bad) Cnidarians , known for stinging cells (cnidocytes) aquatic, mostly marine benthic and pelagic (live on a substrate on bottom, or they swim around) Medusa jellyfish, tentacles go down branch off swims around, motile vs. Box jellyfish have photoreceptors and can see light/crude images. Hydrostatic skeleton- water allows to move two sets of muscles allows them to move relax, contract (antagonistic pairs) are longitudinal and circular.
