BIOL 110 Chapter Notes - Chapter 31: Parazoa, Bilateria, Deuterostome
Document Summary
Animals one - phylogeny and diversity; animals without body cavities - parazoa, radiata, acoelomates. Ability to move; affect motion in the organism"s vicinity. While some animals are sessile as adults, all animals, move at some point during development. The are ingestive heterotrophs, ingest nutrients, bringing them into their bodies for digestion. Animals store their food as glycogen: multicellular. Most animals have muscle tissue and nervous tissue. The origin of animals: choanoflagelltes share features with animals. Colony of individual cells in anchored to a substrate. Each flagellum sweeps food into a cell for ingestion. Cell can then transfer the food to other cells. This organism shoes a primitive form of multicellularity and ingestive heterotrophy. Group of protists most closely related to animals. Parazoa vs. eumetazoa: first dichotomous branching point: seperates organisms that do not have true tissues from those with true tissues. Aggregation of cells that performs a function: parazoans lack true tissues, eumetazoans have true tissues.
