BIO 111 Chapter Notes - Chapter 23: Gastrovascular Cavity, Ventral Nerve Cord, Ctenophora
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23. 1 distinct body plans evolved among the animals. Characteristics used to classify organisms are morphology, multicellularity, heterotrophy, internal digestion, and motility. Strongly correlated with cephalization: cephalization the concentration of sensory organs and nervous tissues at the front of the organism (in the head region) The structure of the body cavity influences movement: acoelomate organisms that lack an enclosed fluid-filled body cavity. Appendages have many uses: enhances the organisms ability to move, sense (antennae), capture food (claws), or reproductive purposes (sperm transfer, egg incubation) Nervous systems coordinate movement and allow sensory processing: nerve nets a diffuse nervous system, central nervous system the nerve system of most bilaterians which controls muscle action and processes sensory information. 23. 2 some animal groups fall outside the bilateria. There are the sponges, the eumetazoans, and the bilateria: eumetazoans all groups that are not sponges and bilateria (ctenophores, placozoans, cnidarians.
