BIO SCI 94 Chapter Notes - Chapter 35: Cartilage, Notochord, Aquatic Feeding Mechanisms

• School: UC-Irvine
• Department: Biological Sciences
• Course: BIO SCI 94
• Professor: Catherine Loudon

Document Summary

Deuterostomes=irst gorup together b/c undergo early embryonic development in similar way. Posterior to anterior- anus forms irst/then mouth does. A coelom, if present, develops from outpockeings of mesoderm. There are 4 deutero phyla: echinodermata, hemichordata, xenoturbellida, chordata. Are abdundant. in deepwater enviro, species in this phylum = 95% of total mass of organisms. All duetero considered to be bilaterians b/c evolved from ancestor that"s bilaterally symmetric. Echino=biilaterians too but early event: echino had origin of 5-sided radial symmetry, called pentaradial symmetry. So tend to interact with enviro in all direcions at once not just one direcion. 2nd feature of echino=endoskeleton: hard structure, located just inside thin layer of epidermal issue, which provides protecion/support. Another event in echino evoluion: morpho feature: series of branching, luid-illed tubes and chambers called water vascular system. Tube feet=elongated, luid illed appendages, each consising of balloon like ampulla on inside of body and tube-like podium (foot) projecing on outside.