BIOLOGY 101 Study Guide - Midterm Guide: Kimberella, Sarcopterygii, Placodermi
Document Summary
When can development regulation occur: changes in gradients of proteins and mrna messages laid down by females in eggs, changes affecting the unfolding of development pattern after fertilization. Hox gene families: allow for a series of duplicated genes that compliment each other. They"re found in a particular order and perform complimentary functions and control certain functions in bodies of many organisms. The same genes are present throughout all organisms, but they are slightly altered depending on what organism. : sponges lack distinctive tissues and instead pump water through body. Diploblast: organism only has two main layers of tissue in its" body. Triploblast: organism has three main layers of tissue in its body. Radial: can be cut in half along many different lines to make mirror images. Bilateral: can be cut along one line to make mirror image. Lacks a body cavity, but still a triploblast. Fluid filled body cavity, still a triploblast, but body isn"t completely isolated from internal tissues.
