BIOL 1002 Chapter : Chapter 23 Animal Diversity I Part 1 USE THIS ONE
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. In addition to these characteristics, as animals evolved, they developed more complex and organized bodies. Some of the differences in complexity and organization are: cellular specialization, body plan, vertebrate vs. invertebrate, cephalization, body cavity (ex. *cephalization is the concentration of nervous tissue (including a brain and sensory organs) into a defined region (head) of the body. *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, Cellular specialization can lead to the development of tissues, which then can lead to the combination of tissues into an organ. Organs may then become arranged into organ systems. An evolutionary tree of some major animal phyla. Epithelial cells -outer covering layer (like a skin).
