BIS2C_Lect26_Ward_Development___Sponges_ppt

Convergently evolved traits clicker question 3 pick

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Unformatted text preview: tly evolved traits. Clicker Question 3. Pick the best answer. Based on the phylogeny presented in the most recent edition of your textbook (Life, 9th Edition), most features that are characteristic of sponges are likely to represent: lik But recent genomic studies (e.g., Philippe et al. 2009 Current Biology 19: 706-712) strongly support monophyly of sponges (tree B). These results are reflected in the most recent of your textbook (Life, 9th Edition). a. b. c. d. Eumetazoan synapomorphies. Synapomorphies of the sponges. Ancestral metazoan conditions. Convergently evolved traits. A = demosponge B = glass sponge C = calcareous sponge 4 Sponges - Asymmetrical - Gutless - Differentiated cell types (no true tissues/organs) - Gelatinous matrix (mesohyl) w/ collagen Sponge features - Spicules (skeletal elements Aquiferous system - water flows continuously into incurrent pores (ostia), traverses internal chambers, and exits out of excurrent pores (oscula) Sponge features • Asymmetrical gutless animals • Aquiferous system: branched water canals • Differentiated cell types but no true tissues or organs • Cells arranged in gelatinous matrix (mesohyl) with collagen and usually spicules (skeletal elements) Flagella helps bring in water and collect food Aquiferous system: water flows continuously into numerous incurrent pores (ostia), traverses internal chambers, and exits out of one or more excurrent pores (oscula); propelled by movement of flagella of many choanocy...
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