BIOL 1002 Chapter : Chapter 23 Animal Diversity I Part 1
Document Summary
Key features of animals: eukaryotic, multicellular, heterotrophic, eat (ingest) other organisms, sexual reproduction, no cell wall, are motile, respond rapidly to external stimuli. Coelom: segmentation, segmentation is a body design in which similar repeating units are present. These and other characteristics are used to define the phyla within the kingdom animalia table 23. 1 (phyla: Porifera, cnidaria, playhelminthes, annelida, mollusca, arthropoda, nematoda, ecinodermata) Cellular specialization can lead to the development of tissues, which then can lead to the combination of tissues into an organ. An evolutionary tree of some major animal phyla. 23-5: epithelial cells outer covering layer (like a skin). Characteristics of sponges: sessile - non-moving, filter feeders, may reproduce sexually or asexually by budding and fragmentation, most species have an asymmetric body plan designed for water filtration, produce toxins, some are used in medicine. All other animal phyla have both defined tissues and symmetry.
