ECK-DICE-OH-ZOH-ENS (minus Insects)1. What characteristics do all organisms in the clade Ecdysozoa share? They’re bilaterally symmetric, triploblastic, protostomes and they molt their exoskeletons for growth.NEMATODA2. All nematodes are covered with a(n) cuticle (exoskeleton), move by contracting muscles against the cuticle, have a(n) complete digestive system and are pseudocoelomates.3. What are 3 ways in which Nematodes are important?1. Act as model organism for humans (C. elegans)2. Important decomposers3. Some are parasites4. What causes a loss of $500 million/year for soybean farmers? Soybean cyst nematode5. We discussed three specific nematode parasites. State how they’re contracted and what they do to their host.Cause of trichinosis: Humans get it from eating undercooked pork. Juveniles encyst in our muscles…this parasite can kill humans…Cause of elephantiasis (lymphatic filariasis): Humans get it from mosquitoes. It causes limbs and other soft tissue to swell, causing disability (due to a blockage of the lymph system).Guinea worm: Humans get it from drinking water with infected copepods (an arthropod). It causes painful, hot blisters on the skin due to adults trying to break through the skin.6. What is the most common parasite in humans? Ascaris sp. Where does it live most of its life? How do we avoid getting it? It mostly lives in our intestines. We must avoid fecal contamination to avoid this parasite.7. What is the most effective way to stop the life cycle of parasites? Get rid of the intermediate host!ARTHROPODA8. What are the four characteristics that describe the incredibly successful arthropods? How are these characteristics important to their success?1. Segmented body—allows for specialization of different segments of the body; a reduction in segmentation has led to a more efficient body plan2. Exoskeleton—prevents water-loss, provides a structure for muscle attachment, protection3. Jointed appendages—increases mobility and specialization of limbs4. Well-developed head and sensory organs—increase specialization, etc.9. Fill in the following table with information about each clade of the arthropods (minus Insecta).Clade Species? 2 Body Regions Antennae LegsChelicerata Spiders, ticks, scorpionsCephalothorax, abdomenNone 4 pairsCrustacea Crabs, shrimps, barnacles, copepods…Cephalothorax, abdomen2 pairs >5 pairsMyriapoda Millipedes, centipedes Head, abdomen 1 pair
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