Bio Notes March 9

Bio Notes March 9 - The ancestor probably resembles modern...

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Bio Notes March 9 Animal Diversity ( starting chapters 32 +33) Mandatory Reading- ch 33 Fungi- rich group where they have a common protest ancestor. Animals are very diverse, 1.8 million species of animals most of which belong mostly to insects. Mammals have something around 4000 species. What is an animal? All animals are mulitcellular, eukaryotic organisms that are hetertrophs, undergo sexual reproduction. (voluntary movement) , (ingest their food), (nerve cells), (mostly diploid, there are some exceptions) (Most animals are motile, some are sessile .) Most animals are invertebrates. -Cells are held together by extracellular matrix proteins and junctions. I.E. Tight junctions. -Have muscle cells for movement and nerve cells for conducting impulses. -Most are diploid and reproduce sexually. We have somewhere between 36 and 43 phyla. Points of Agreement: -single common ancestor -sponges are basal animals The common ancestor of living animals have lived 1.2 billion-800 million years ago.
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Unformatted text preview: The ancestor probably resembles modern choenoflagellates? Paleozoic Era Cambrian explosion, created new ecological inches, unique because there was not an immediate extinction happening before. Scientists came up with some hypotheses: 1. New predator-prey relationships developing. 2. O2 increases dramatically. Homologous Hox genes establish body plans in animals that have not shared a common ancestor in hundreds of millions of years. In addition, major evolutionary changes may be based on Hox genes. Grade Porifera:- Sponges called Porifera imply a monophyletic clade, but this is NOT TRUE. They are much more complex than this. (Pore carriers, meaning they have lots of pores), Adults: sessil, filter feeders Larvae- motile Vast majority have no symmetry, no true tissues, and are mostly marine. Bernaullis Principle (has a net-like feeding structure. ) 1. 2....
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This note was uploaded on 03/19/2012 for the course BISC 1112 taught by Professor Doebel during the Spring '12 term at GWU.

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Bio Notes March 9 - The ancestor probably resembles modern...

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