BIOL 2030 Chapter Notes - Chapter 8: Symmetry In Biology, Osmoregulation, Turbellaria
26 Apr 2016
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Bilateral symmetry is an adaptive value because their sensory structures are concentrated anteriorly, which is the end that first encounters environmental stimuli: match the terms in the right column with the classes in the left column. Cestoda- endoparasitic: give several major characteristics that distinguish platyhelminthes, rather than epidermis they contains a body covering called tegument. Yolk is contributed by cells release from separate organs. Nutrition for the embryo is contained in the egg cell, endolecithal. Mouth is usually at the anterior end, and the pharynx is not protrusible. Intestinal secretion consists of enzymes for extracellular digestion. Food is sucked into the intestine where it completes digestion. Undigested food is egested through the pharynx: briefly describe the osmoregulatory system and the nervous system and the sense organs of the platyhelminths. The most primative nervous system is a subepidermal nerve plexus, resembling the nerve net of cnidarians. Other flatworms also have 1-5 pairs of longitudinal nerve cords laying under the muscle layer.
