BIO 012 Lecture Notes - Lecture 4: Epithelium, Muscle Tissue, Body Plan
19 Sep 2017
School
Department
Course
Professor
Document Summary
Traits of these shared features: embryonic development. Selection pressures influence body plan, governs evolution: body symmetry. Cut through any plane and get two identical halves. Cut in half, any cut through the center on only one plane, gives. Only one cut through only one plane makes identical halves. Bilateralization has been linked to cephalization (the appearance of the head) Doesn"t include organs, only external features: structure of body cavity. Cavity is the space of which your organs reside in. Acoelomates: no cavity between gut and muscle body wall, organs attach right to body wall. Pseudocoelomates: have cavity between gut/organs and muscle body wall, but it is filled with fluid. Coelomates: have true empty cavity between gut/organs and muscle body wall. Type of cavity you have determines how you move through the environment. Can see segmentation concept at many levels. Segmentation leads to independent function: external appendages. These are linked to an organism"s relationship to their environment.
