11.2: Invertebrate Evolution Difficulty Level: At Grade Created by: CK-12 Estimated5 minsto complete % Progress Practice Invertebrate Evolution MEMORY METER This indicates how strong in your memory this concept is Practice Progress Estimated5 minsto complete % Estimated5 minsto complete % Practice Now MEMORY METER This indicates how strong in your memory this concept is Share Add to Library Turn In Read Practice Resources Details Loading... Notes/Highlights Having trouble? Report an issue. Color Highlighted Text Notes Show More Vocabulary Language: English ▼ English Spanish TermDefinition bilateral symmetry Symmetry of a body plan in which there are distinct head and tail ends, so the body can be divided into two identical right and left halves. cephalization Concentration of nerve tissue in one end of an animal, forming a head region. coelom Fluid-filled body cavity. complete digestive system Digestive system consisting of a digestive tract and two body openings (mouth and anus). ectoderm Outer embryonic cell layer in animals. endoderm Inner embryonic cell layer in animals. hydrostatic skeleton Type of internal support in an animal body; results from the pressure of fluid within the body cavity known as the coelom. mesoderm Embryonic cell layer in many animals that is located between the endoderm (inner cell layer) and ectoderm (outer cell layer). pseudocoelom Partial, fluid-filled cavity inside the body of some invertebrates. radial symmetry Symmetry of a body plan in which there is a distinct top and bottom but not distinct head and tail ends, so the body can be divided into two halves like a pie. segmentation Division of an animal body into multiple segments. symmetry The characteristic of having two identical halves, such as in a symmetrical organism. multicellularity Composed of more than one cell. Image Attributions Show Hide Details Description An overview of the major events in invertebrate evolution. Learning Objectives None Related Materials Invertebrate Evolution - Advanced Difficulty Level: At Grade Authors: Douglas Wilkin, Ph.D. Jean Brainard, Ph.D. Tags: cephalization coelom invertebrates (4 more) mesoderm notochord SCI.BIO.815.L.1 symmetry Subjects: science Biology Concept Nodes: SCI.BIO.815 (Invertebrate Evolution) Grades: 9 , 10 Date Created: Feb 24, 2012 Last Modified: Sep 04, 2016 Vocabulary None Save or share your relevant files like activites, homework and worksheet.To add resources, you must be the owner of the Modality. Click Customize to make your own copy.