BIOL 102 Lecture Notes - Lecture 16: Ectotherm, Parthenogenesis, Cambrian Explosion
Document Summary
1. 3 million living species of animlas have been indentified. 1 nervous tissue and muscle tissue which are unique to animals. Animals are heterotrophs that ingest their food (don"t make our own food) Gastrula: layers of outside cells start migrating towards the inside of the cell (3 layers: ectoderm, endoderm. Triploblastic embryo (3) layers (extra mesoderm) humans are triploblastic. Hox genes: making sure metamorphosis happens in the correct way: paleozoic era (542-251 million years ago) Dinosaurs were dominant terrestrial vertebrates, coral reefs and first mammals emerged. 3. ) cenozic era (65. 5 million years ago to present) Dinosaurs went extinct, mammals became more dominant (adaptive radiation, when dino went extinct and mammals took over) Radial symmetry: left is identical to the right no matter how it is cut in half (ex. 3. ) body cavities: no body cavity (ex tape worm) 2. ) coelomate : (ex human), cavity is in good shape.
