BSC 1011 Ch. 33

A confused friend from your course has made a Halloween costume that is supposed to show one animal phylum. It has a hard outer shell and a water vascular system. You point out that the costume combines features of _____. A. Arthropoda and Echinodermata B. Echinodermata and Chordata C. Chordata and Cnidaria D. Platyhelminthes and Cnidaria E. Cnidaria and Porifera

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A land snail, a clam, and an octopus all share ________. A. a mantle B. a radula C. gills D. distinct cephalization

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A newly discovered species of shelled marine organism could be a(n) _____. A. mollusc B. ectoproct C. brachiopod D. a or b E. a or c

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A terrestrial animal species is discovered with the following larval characteristics: exoskeleton, system of tubes for gas exchange, and modified segmentation. What other characteristic is most likely present in this organism? A. eight legs B. two pairs of antennae C. a sessile lifestyle D. an open circulatory system

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Against which of the following do the circular and longitudinal muscles of annelids work? A. cuticle B. shell C. endoskeleton D. hydrostatic skeleton

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As you are walking along a beach, you find an animal and believe that it belongs to the class Asteroidea. Which of the following characteristics would support your hypothesis that the animal is a sea star and not another type of echinoderm? A. It is radially symmetric. B. It feeds on other animals. C. It has a hydrostatic skeleton, formed from its water vascular system. D. It has five or more appendages.

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Echinoderms show enormous diversity in which of the following traits? A. body shape and food habits B. food habits and body symmetry C. body symmetry and method of food digestion D. method of food digestion and body shape

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From question 10, in the second part of the experiment, why did the researchers present unshelled periwinkles to crabs? A. to test if either population of periwinkles was unpalatable B. to either population of crabs C. to feed crabs that were unable to open the periwinkles provided as potential prey D. to test if crabs preferentially selected prey based on the color of their shells E. to test if the periwinkle flesh was tougher from one source than from the other

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From question 10, which best summarizes the results shown in the graph? A. Crabs are more successful in preying on northern periwinkles. B. Crabs are equally successful in preying on northern and southern periwinkles. C. Crabs are more successful in preying on southern periwinkles.

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From question 10, which is the dependent variable in the first part of this experiment? A. the shell thickness of the periwinkles B. the number of periwinkles killed by crabs C. the shell thickness of the crabs D. the size of the crabs' claws

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If you brush your fingers along the tentacles of a sea anemone, which of the following are you most likely to find upon microscopic examination of your fingers? A. teeth marks B. spines C. spicules D. nematocysts

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If you discovered a new organism with 10 jointed legs, you would expect it to have _____. A. a water vascular system B. a closed circulatory system C. muscles attached to an exoskeleton D. a radula

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If you wanted to obtain a large amount of nervous tissue with the least amount of dissection and processing, what phylum would you use for your sample? A. Nematoda B. Arthropoda C. Mollusca D. Chordata

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If you wanted to show an example of segmentation to a group of visiting students, which phylum would be the best choice? A. Nematoda B. Arthropoda C. Mollusca D. Chordata E. Cnidaria

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In a tide pool, a student encounters an organism with a hard outer covering that contains a large amount calcium carbonate, an open circulatory system, and gills. The organism could potentially be a crab, a shrimp, a barnacle, or a bivalve. The presence of which of the following structures would allow for the most definitive identification of the organism? A. a mantle B. a heart C. a body cavity D. a filter-feeding apparatus

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In the below figure, assume that the two medusae shown at step 4 were produced by one polyp colony. Review Concept 12.1 and Concept 13.3, and then use your understanding of mitosis and meiosis to select which of the following is true.

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In these figures, which two main clades branch from the most recent common ancestor of the eumetazoans? A. Porifera and Cnidaria B. Lophotrochozoa and Ecdysozoa C. Cnidaria and Bilateria D. Deuterostomia and Bilateria

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Nudibranchs, a type of predatory sea slug, can have various extensions on their dorsal surfaces. Rhinophores are paired structures, located close to the head, which bear many chemoreceptors. Dorsal plumules, usually located posteriorly, perform respiratory gas exchange. Cerata usually cover much of the dorsal surface and contain nematocysts at their tips. The antennae of insects have a function most similar to that of ________. A. rhinophores B. dorsal plumules C. cerata D. eyes

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Of the animal phyla listed, which has least in common with the rest? A. Nematoda B. Arthropoda C. Mollusca D. Chordata E. Cnidaria

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Our understanding of many of the evolutionary relationships among animals changed after those phylogenies were based on morphological and molecular data (as opposed to only using morphological data). Which of the following groups represents an example of this change? A. Locotrophozoa B. Placozoa C. Brachiopoda D. Bivalvia

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Our understanding of many of the evolutionary relationships among animals changed after those phylogenies were based on morphological and molecular data (as opposed to only using morphological data).What do these changes indicate? A. molecular and morphological studies rarely agree B. molecular studies add additional information to morphological studies and improve our understanding of evolutionary history C. molecular studies are less reliable than morphological studies D. molecular studies are extremely time consuming and expensive and really don't add additional information to our understanding of evolutionary history

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Researchers collected periwinkles and crabs from sites in the northern and southern parts of the Gulf of Maine. A single crab was placed in a cage with eight periwinkles of different sizes. (All crabs were of similar size and included equal numbers of males and females.) Four treatments were set up, and each treatment was tested 12 to 14 times: Northern crab caged with northern periwinkles Northern crab caged with southern periwinkles Southern crab caged with northern periwinkles Southern crab caged with southern periwinkles After three days, the researchers assessed the fate of the eight periwinkles. The bar graph shows the data from this experiment. In a second experiment, the researchers removed the bodies of northern and southern periwinkles from their shells and presented the bodies to northern and southern crabs. The crabs consumed all of the unshelled periwinkles in less than an hour. Which is an independent variable in the first part of this experiment? A. the number of periwinkles killed by crabs B. the shell thickness of the periwinkles C. the shell thickness of the crabs D. the source of the periwinkles (northern or southern sites the Gulf of Maine)

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Sexual reproduction leads to increased genetic variation, but male bdelloid rotifers have never been observed. Which of the following are correct statements with regard to evolution in bdelloid rotifers? A. As we learn more about bdelloid rotifers, we find males in more and more species. B. Bdelloid rotifers gain genetic variation by absorbing DNA from the external environment. C. Protists infect bdelloids and bring DNA from other rotifers with them. D. Bdelloid rotifers have lost the ability to reproduce sexually only recently.

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Soft-shell crab is a prized dish in many ocean-side resorts. Which of the following statements provides the best explanation for the soft shell of the crabs? A. The crab has just molted and the new exoskeleton has not yet hardened. B. These species of crabs live under rocks and therefore have lost the hard exoskeleton over evolutionary time. C. These species have evolved a light and soft exoskeleton so that gases can diffuse directly between body of the crab and the surrounding water. D. These species have evolved a light and soft exoskeleton so that they can float in the water column.

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The best example of an animal phylum with enhanced overall surface area is _____. A. Cnidaria B. Nematoda C. Annelida D. Platyhelminthes E. Echinodermata

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The crown-of-thorns sea star, Acanthaster planci, preys on the flesh of live coral. If coral animals are attacked by these sea stars, then what part of the coral actually provides nutrition to the sea star? A. medusae B. exoskeleton C. polyps D. gametes

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The dominant invertebrate predator of the seas for hundreds of millions of years until the mass extinction at the end of the Cretaceous period was the A. lamprey. B. annelid. C. ammonite. D. anemone. E. squid.

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The heartworms that can accumulate within the hearts of dogs and other mammals have a hemocoel, an alimentary canal, and an outer covering that is occasionally shed. To which phylum does the heartworm belong? A. Platyhelminthes B. Arthropoda C. Nematoda D. Annelida

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The increase in plant species diversity is correlated with which of the following events? A. the evolution of complete metamorphosis in insects B. the evolution of flight in insects C. invasion of marine habitats by insects D. a massive increase in species diversity of insects

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The least-important threat faced by freshwater and terrestrial molluscs is _____. A. habitat loss B. pollution C. competition or predation by non-native species D. overharvesting E. changes in how water is released from dams

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The major difference between the two divisions of annelids, the errantians and sedentarians, is that _____. A. sedentarians are less mobile than errantians B. sedentarians are more mobile than errantians C. sedentarians contain parapodia D. errantians include leeches E. sedentarians are all marine organisms

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The phylum Cycliophora includes tiny organisms that live in large numbers on the outsides of the mouthparts and appendages of lobsters. The feeding stage permanently attaches to the lobster and collects scraps of food from its host's feeding by capturing the scraps in a current created by a ring of cilia. The feeding stage of cycliophorans is best described as ________. A. autotrophic and captures food in a manner similar to gastropods B. sessile and captures food in a manner similar to that of animals with lophophores C. sessile and radially symmetric D. autotrophic and sessile

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The phylum Cycliophora includes tiny organisms that live in large numbers on the outsides of the mouthparts and appendages of lobsters. The feeding stage permanently attaches to the lobster via an adhesive disk and collects scraps of food from its host's feeding by capturing the scraps in a current created by a ring of cilia. The body is saclike and has a U-shaped intestine that brings the anus close to the mouth. Cycliophorans have a coelom, do not molt (though their host does), and their embryos undergo spiral cleavage. Based on the information provided, to which clades should cycliophorans belong? A. Eumetazoa and Bilateria B. Eumetazoa and Lophotrochozoa C. Deuterostomia and Ecdysozoa D. Deuterostomia and Lophotrochozoa

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The presences of which of the following anatomicals would best distinguish a gastropod from a chiton? A. presence of a muscular foot B. presence of a rasp-like feeding structure C. production of eggs D. dorsal plates

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The sharp, inch-long thorns of the crown-of-thorns sea star are its spines. These spines, unlike those of most other sea stars, contain a potent toxin. If it were discovered that crown-of-thorns sea stars do not make this toxin themselves, then what is the most likely alternative source for the toxin? A. it is derived from the nematocysts of its prey B. it is absorbed from the surrounding seawater C. it is an endotoxin of cellulose-digesting bacteria that inhabit the sea star's digestive glands D. it is injected into individual thorns by mutualistic corals which live on the aboral surfaces of these sea stars

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The water vascular system of echinoderms ________. A. functions as a circulatory system that distributes nutrients to body cells B. functions in locomotion and feeding C. is bilateral in organization, even though the adult animal is not bilaterally symmetrical D. moves water through the animal's body during filter feeding

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What would be the most effective method of reducing the incidence of blood flukes in a human population? A. reduce the mosquito population B. reduce the population of the intermediate snail host C. avoid contact with rodent droppings D. carefully wash all raw fruits and vegetables

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What would the presence of a lophophore in a newly discovered species suggest about that organism? A. it has an exoskeleton B. it grows by shedding its external covering C. it is motile D. it feeds by trapping food particles suspended in the water

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Which of the following adaptations led to an explosion in insect evolution? A. exoskeleton B. tracheal system C. flight D. terrestrial living

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Which of the following animal groups is entirely aquatic? A. Mollusca B. Crustacea C. Echinodermata D. Nematoda

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Which of the following characteristics do all insects exhibit? A. they undergo complete metamorphosis and have segmented bodies B. they have jointed appendages and a radula C. they have an exoskeleton or cuticle D. they have jointed appendages and spicules

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Which of the following characteristics is exhibited by most hydrozoans? A. polyp form only B. bilateral symmetry C. lack of symmetry D. both polyps and medusa forms

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Which of the following characteristics is exhibited by the water vascular system of echinoderms? A. it functions as a circulatory system that distributes nutrients to body cells B. it functions in locomotion and feeding C. it is bilateral in organization, even though the adult animal is not bilaterally symmetrical D. it is analogous to the gastrovascular cavity of flatworms

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Which of the following characteristics is shared by both cnidarians and flatworms? A. dorsoventrally flattened bodies B. radial symmetry C. a digestive system with a single opening D. a distinct head

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Which of the following characteristics of parasites explains how parasitism has become so widespread among living organisms? A. Parasites almost always predigest their hosts' tissues and, therefore, spend less energy and require fewer structural adaptations. B. Parasites, unlike predators, feed on almost all the tissues of their host. C. Parasites do not generally kill their hosts; thus, they can feed on the same host throughout the host's normal life span and do not have competition from decomposers. D. Parasites generally kill their host and can feed for a very long time because they are much smaller than their host.

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Which of the following characteristics of their exoskeletons is exhibited by both arthropods and molluscs? A. they completely replace the hydrostatic skeleton B. they are secreted by the mantle C. they help retain moisture in terrestrial habitats D. they are comprised of the polysaccharide chitin

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Which of the following combinations correctly matches a phylum to its description? A. Echinodermata-bilateral symmetry as a larva, water vascular system B. Nematoda-segmented worms, closed circulatory system C. Cnidaria-flatworms, gastrovascular cavity, does not have a coelom or a hemocoel D. Platyhelminthes-radial symmetry, polyp and medusa body forms

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Which of the following combinations of phylum and description is incorrect? A. Echinodermata-bilateral symmetry as a larva, coelomate B. Nematoda-roundworms, pseudocoelomate C. Platyhelminthes-flatworms, gastrovascular cavity, acoelomate D. Porifera-gastrovascular cavity, coelomate

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Which of the following feeding strategies is most likely to be used by aquatic organisms? A. filter feeding B. mass feeding C. deposit feeding D. fluid feeding

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Which of the following groups of organisms has flagella associated with its method of feeding? A. annelids B. coral animals C. tapeworms D. sponges

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Which of the following organisms uses a lophophore for feeding? A. hydra B. sponge C. gastropod D. ectoproct

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Which of the following senses would be most directly affected by removing or damaging an insect's antennae? A. hearing B. mating C. seeing D. smelling

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Which of the following statements about bryozoans (ectoprocts) is correct? A. Bryozoans are colonial, build reefs, and are related to corals. B. Bryozoans are colonial and live amongst mosses. C. Adult bryozoans are sessile, but their larvae make up much of marine plankton. D. Bryozoans build reefs and have lophophores that extend through a hard exoskeleton.

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Which of the following statements applies to both nematodes and arthropods? A. develop an anus from the blastopore (pore) formed in the gastrula stage B. are parasites C. grow in conjunction with shedding of their exoskeleton D. have ciliated larvae

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Which of the following statements best explains how planarians can survive and thrive without respiratory or circulatory systems? A. none of their cells are far removed from the gastrovascular cavity or from the external environment B. they lack mesoderm as embryos and, therefore, lack the adult tissues derived from mesoderm C. their flame bulbs can carry out respiratory and circulatory functions D. their body cavity, a pseudocoelom, carries out these functions

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Which of the following statements correctly describes one difference between nematodes and arthropods? A. nematodes have an open circulatory system and arthropods have a closed circulatory system B. nematodes shed their cuticle when they grow but arthropods do not C. arthropods have an open circulatory system while nematodes do not have a circulatory system D. arthropods shed their cuticle when they grow but nematodes do not

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Which of the following statements describes how healthy corals appear brightly colored? A. hey secrete colorful pigments to attract mates B. they host symbionts with colorful photosynthetic pigments C. they build their skeletons from colorful minerals D. they secrete colorful pigments to protect themselves from ultraviolet light

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Which of the following statements describes sponges? A. they have larvae that are motile and move via the motion of flagella B. they are the simplest diploblastic animals C. they have a nerve net but not a central nervous system D. they have feeding cells called dinoflagellates

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Which of the following statements is correct with respect to the evolutionary relationship between chordates and invertebrates? A. Chordates are most closely related to arthropods. B. Chordates evolved from echinoderms. C. Chordates are more closely related to echinoderms than to arthropods. D. Chordates are most closely related to the tunicate-type of echinoderms.

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Which of the following structures can be found in the mesohyl of a sponge? A. amoebocytes and choanocytes B. spicules and choanocytes C. amoebocytes and spicules D. amoebocytes and polyps

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Which of the following structures in insects functions in gas exchange? A. compound eyes B. spiracles C. antennae D. chelicerae

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Which one of these mollusc groups is classified as suspension feeders? A. bivalves B. gastropods C. chitons D. cephalopods

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Which phylum has a water vascular system? A. molluscs B. echinoderms C. cnidarians D. annelids E. arthropods

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Which phylum is characterized by animals that have a segmented body? A. Cnidaria B. Platyhelminthes C. Arthropoda D. Mollusca

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Which sponge cell is most structurally and functionally similar to the cnidocyte of a cnidarian? A. amoebocyte B. choanocyte C. epidermal cell D. pore cell

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Which statement about arthropods would lose points on an exam? A. Arthropods have an open circulatory system. B. Arthropods have well-developed sensory organs. C. Arthropod bodies are completely covered by a cuticle. D. Terrestrial arthropods have internal structures specialized for gas exchange. E. Most arthropod sensory organs are concentrated at the posterior end.

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Which statement about molluscs would lose points on an exam? A. There are over 100,000 known species. B. They are the most diverse phylum. C. All molluscs have the similar body plan. D. Three-quarters of living species are gastropods. E. The phylum Mollusca has eight major clades.

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Which statement about nematodes is incorrect? A. Nematodes are found in most aquatic habitats. B. They have no circulatory system. C. They include many species that parasitize plants and animals. D. They play roles in decomposition and nutrient cycling. E. Trichinella spiralis has become a model research organism in biology.

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Which structure do sea slugs use to feed on their prey? A. nematocysts B. an incurrent siphon C. a radula D. a mantle cavity

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Which would be a great surprise if found in the body of a sponge? A. spongocoel B. osculum C. mesohyl D. limb

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While sampling marine plankton in a lab, a student encounters large numbers of fertilized eggs. The student rears some of the eggs in the laboratory for further study and finds that the blastopore becomes the mouth. The embryo develops into a trochophore larva and eventually has a coelom and a hemocoel. To which group of organisms did these eggs likely belong? A. echinoderms B. molluscs C. nematodes D. arthropods

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Whiteflies are common pest insects found on cotton, tomato, poinsettia, and many other plants. Whitefly nymphs are translucent and mostly sessile, feeding on their host plant's phloem (sap) from the undersides of leaves. They undergo incomplete metamorphosis into winged adults. Because whitefly nymphs cannot escape predation by moving, you hypothesize that their translucent bodies make them hard to spot by predators. Which experimental approach is best for testing your hypothesis? A. Compare rates of predation on whitefly nymphs on plant leaves of different colors (for example, red versus green poinsettia leaves). B. Compare rates of predation on whitefly nymphs coated with a nontoxic dye versus undyed whitefly nymphs. C. Compare rates of predation on whitefly nymphs versus whitefly adults. D. Compare rates of predation on whitefly nymphs by predators that are translucent versus predators that are not translucent.

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Why do large animals need specialized organs for gas exchange? A. they require more oxygen per unit of volume B. surface area increases more rapidly than volume as size increases C. volume increases more rapidly than surface area as size increases D. they collect more energy and therefore have more energy to allocate to specialized tissues

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You are a research chemist who wishes to develop a chemical adhesive that will work under water. Which of the following organisms would give you the best clue about where to start? A. sea wasps B. trematodes C. lobsters D. mussels

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You find a multi-legged animal in your garden and want to determine if it is a centipede or a millipede. Which of the following characteristics would allow you to make this distinction? A. presence of body segments B. poisonous claws C. egg-laying D. molting

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You find what you believe is a new species of animal. Which of the following characteristics would enable you to argue that it is more closely related to a nematode than it is to an annelid? A. It is a suspension feeder. B. It has a hemocoel. C. It is shaped like a worm. D. It has a mouth and an anus.

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Your friend, who was setting up a lab on arthropods for your class, put out specimens of the following groups. Which needs to be removed? A. chelicerates B. myriapods C. pancrustaceans D. ophiuroids

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