ZOO 2700 Lecture Notes - Lecture 5: Animal, Multinucleate, Synapomorphy
Document Summary
Cells and tissues: mobile, heterotrophic, mulitcellular, cevelop from embryos, tissues - specialized cells bound together. Somatic cell differentiation: epithelium - sheet of cells, connective tissue - cells + ecm, collagen - probably the most important structural protein, apomorphy for metazoans, tangle of hair cells only found in animals. Advantages of multicellularity: many differences due to size and the ratio of surface area (sa) to volume (v, the surface is the interface between the organism/cell and its environment, division of labour, efficiency. Inc in size: ecological adv, metabolic adv, complex tasks. Surface area to volume and cells: # of reactions increase as volume increase, materials for these reactions have to enter cell across the membrane, at so(cid:373)e poi(cid:374)t sa (cid:449)ill (cid:271)e too s(cid:373)all to allo(cid:449) . Sa of cell controls how much can enter the cell. "how are permits ants (or other small animals) so strong ? " Strength scales with the x-sectional area of muscle!