BIOL 202 Study Guide - Final Guide: Crustacean, Spongillidae, Egg Cell
Document Summary
Who are the invertebrates: 1) diploblasts and triploblasts 2) protostomes ( iochotrophozoans and ecdoysozoans) and deuterosomes 3) acoelomates, Why study the invertebrates: 1) abundance 2) ecosystem significance 3) food 4) diseases 5) pests 6) natural products 7) research. Animals that lack a backbone ( not vertebrates). They include many phyla and their taxonomy is regularly changing ( as science is progressing we are finding more and more ways to sort these organisms and discover that techniques once used are not reliable). They can be subdivided into different groupings based on different distinguishing features. Tissue layers: 1) no tissue layers : placozoans & poriferans( basically collections of cells, most primitive state of invertebrates) 2) two tissue layers: diploblasts ( two basic layers possible interlayer space). Triploblasts are often further divided into groups based upon the nature of coelom ( an internal body cavity). 1) acoelomate: no body cavity 2) pseudocoelomate: forms between endoderm and mesoderm.
