BIOL 1108 Study Guide - Midterm Guide: Symmetry In Biology, Eumetazoa, Bilateria
Document Summary
44. 1 - a tree of life for more than a million animal species. Phylogenetic trees propose an evolutionary history of animals. Animals can be described as multicellular heterotrophic eukaryotes that form a gastrula during development. Morphology and development provide clues to animal phylogeny. Radial symmetry allows for jellyfish to move up and down in the water column by flexing muscles around their bell-like bodies. Acoelomates - those without a body cavity. Coelomates and pseudocoelomates - those with a body cavity. Phylum that includes jellyfish and sea anemones. Embryo has two germ layers - the endoderm and the ectoderm. Molecular sequence comparisons have confirmed some relationships and raised new questions. Molecular sequence comparisons confirm the view that choanoflagellates are the closest protist relatives of animals. 44. 2 - the simplest animals: sponges, cnidarians, ctenophores, and placozoans. Sponges are simple and widespread in the oceans. Cells that line the interior surface of sponges and have flagella and function in nutrient gas exchange.
