BIOL 1010U Lecture Notes - Lecture 5: Choanocyte, Eumetazoa, Cellular Differentiation
Document Summary
Textbook reference: chapter 44 in biology how life works (2nd ed. ) Sections 44. 1 44. 2; pp. 946 to 956. Despite millions of years of evolution, animal body plans remain fairly consistent across phyla only minor variations wings, fins, legs. Four major patterns in body plans useful in classifying animals: symmetry, tissue orientation, body cavities, orientation of the mouth and anus. The manifestation of patterns in animal body plans is often seen in the adult, but sometimes present only in the embryo or larva. Animals can be categorized according to the symmetry of their bodies (or lack of it): dorsal/ventral, anterior/posterior, and oral/aboral. Some animals that look very different as adults share patterns of early embryological development. Biologists divide animals into two groups based on the number of germ layers that develop from the blastula: diploblasts and triploblasts. Define coelom = space inside the body, usually fluid, where organs develop, move, and are cushioned from outside shocks.
