Where would you place a creature that has the following characters: can burrow in sediment; moves by means of "clapping" two valves together, lacks a radula; eyes with a retina; shell with an umbo? Bivalvia Which of the following is NOT correct? The Mollusca have metanephridia for a circulatory system Which of the following is NOT correct? Members of the Class Monoplacophora are all extinct Which of the following is mismatched? Operculum–an opening in the shell of a gastropod In most freshwater clams fertilization is internal and the fertilized eggs develop into glochidia. True The early nautiloid and ammonoid shells were heavy but made buoyant by a series of gas chambers connected by a cord of living tissue called a? Siphuncle Some cephalopods are hermaphrodites. False
Nematodes are the most important pseudocoelomate animals, both in terms of numbers and their impact on humans. True Nematodes may be which of the following? All of the above
Virtually every species of vertebrate and many invertebrates serve as hosts for one or more types of parasitic nematodes. True Which of the following is incorrect? Parastic nematodes–have an advanced Krebs cycle for metabolism It is estimated that nearly 1.27 billion people are infected worldwide with Ascaris lumbricoides. True Which of the following is not correct? The dog heartworm is troublesome, but not dangerous. Which of the following is NOT considered to be an ecdysozoan? Brachiopoda Which of the following is NOT an external feature of the onychophorans? Chelicerae Onychophorans are similar to insects in that they have a tracheal system that ramifies to all parts of the body and communicates with the outside by means of spiracles. True The onychophorans have a closed circulatory system. False
Legs of the insects are...