BIOL 2200 Chapter Notes - Chapter 32: Ediacaran Biota, Neoproterozoic, Cambrian Explosion

• School: University of Virginia
• Department: Biology
• Course: BIOL 2200
• Professor: Jessamyn Manson

Document Summary

32. 1 animals are multicellular, heterotrophic eukaryotes with tissues that develop from embryonic layers. Increase in oxygen led to larger organisms with higher metabolic rates to thrive while harming other organisms: genetic evolution of body development genes led to newer and more body forms, mesozoic era (251-65. 5 mya) Increase in diversity of animal phyla: cenozoic era (65. 5 mya to present, disappearance of dinosaurs and marine reptiles, rise of mammals. Spiral cleavage (smaller cells grow on the grooves of larger cells) Determinate cleavage (fate of each developmental cell is fixed and has a. Radial cleavage (cells re aligned, one cell above the other) Indeterminate cleavage (each cell has the potential to become its own embryo specific function; each cell cannot function independently: coelom formation. When archenteron (gut) forms, portions of mesoderm split and form the coelom. Mesoderm buds from the wall and cavity becomes the coelom: fate of blastopore.