ECOL 170C1 Lecture Notes - Lecture 15: Calcareous Sponge, Silicon Dioxide, Filter Feeder
20 Feb 2017
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Document Summary
A clade generally classified as protists but are closer to animals than plants (unlike other protist clades) Unicellular eukaryotes that are sister clade to animals. About 125 species, either freshwater or marine. Most animals can move at some point during their life cycle. Movement is made possible by muscle tissue and coordinated nervous system. Animals don"t have cell wall made of chitin. Animals digest their food internally, fungi do externally. Animals share two derived traits that distinguish them from other groups, both associated with holding cells and tissues together. Have unique junctions between cells that hold them together and allow cells to communicate. Have an extracellular matrix that surrounds cells and helps hold tissues together. About 1. 2 million species described, about 1. 6 species of living organism. About 80% of all described species are animals. Most animal species are insects (about a million) Animals are about a billion years old (at least 800 million)
