BIOL 101 Lecture Notes - Lecture 7: Gastrovascular Cavity, Germ Layer, Symmetry In Biology
Document Summary
Radial symmetry: basic body plan in which the organism can be divided into similar halves by passing a plane at any angle along a central axis. Bilateral symmetry: basic body plan in which the left and right sides of the organism can be divided into approximate mirror images of each other along the midline. Gastrovascular cavity: cavity has only one opening to outside, surrounded by mobile tentacles that capture prey. Digestive cavity like this, single opening that functions as both mouth and anus, called a gastrovascular cavity. Incomplete gut (= blind gut): one opening, digestive system with a mouth and a gastrovascular cavity. Complete gut: complete digestive system, (two openings) digestive system with a mouth, gut, and an anus. True tissue: true tissue means germ layer tissue during embryonic development - ectoderm, endoderm, mesoderm. Diploblastic germ layers : endoderm (inner layer), the ectoderm (outer layer), and the mesoderm (middle layer). The germ layers form during the process of gastrulation,
