BIOL 112 Chapter Notes - Chapter 30: The Animal Kingdom, Symmetry In Biology, Cnidaria
Document Summary
30 the animal kingdom: an introduction to animal diversity. Animals: eukaryotic, multicellular, all are heterotrophic ingest food then digest locomotion at some time during life cycle, most have a nervous system and muscles, multicellular diploid stage and a unicellular haploid stage (gametes) Germ layers: separate tissue layers during early development: outer layer (ectoderm, gives rise to body covering, nervous system. Embryo development: blastopore: first opening from embryonic gut to outside, zygote undergoes cleavage, cleavage-mitotic cell divisions of early embryo without cell growth. In protostomes: meaning first the mouth : develops into the mouth. In deuterostomes: meaning second the mouth : becomes the anus. Body cavity (coelom: acoelomate, no body cavity, pseudocoelomate, body cavity not completely lined with mesoderm, coelomate, (animal with true coelom, body cavity completely lined with mesoderm. Adaptations: fossils and comparisons based on molecular evidence suggest that the first animals inhabited shallow marine environments, suggests that adaptations have allowed animals to colonize every other environment on.
