Chapter 33 (Exam 2)

One should expect to find cilia associated with the feeding apparatus of _____. A) annelids B) coral animals C) tapeworms D) sponges

Sponges _____. A) have larvae which are motile and move via the motion of cilia B) are the simplest diploblastic animals C) have a nerve net but not a central nervous system D) have feeding cells called dinoflagellates

Which of the following is most likely to be aquatic? A) suspension feeder B) mass feeder C) deposit feeder D) fluid feeder

Comb jellies may not be the most familiar animal to you, but they are critical in the food chain because they make up a significant portion of the planktonic biomass. Their feeding strategy is predatory and involves adhesives or mucus on their tentacles or other body parts. What feeding tactic do these animals use? A) suspension feeder B) fluid feeder C) deposit feeder D) food-mass feeder

Which of the following can be found in the mesohyl of a sponge? 1. amoebocytes 2. spicules 3. spongin 4. zygotes 5. choanocytes A) 1 and 2 B) 2, 3, 4 C) 1, 2, 3, and 4 D) 1, 2, 3, 4, and 5

Which of the following factors, when used to label the horizontal axis of the graph above, would account most directly for the shape of the plot? A) rate of cribrostatin synthesis (molecules/unit time) B) number of pores per sponge C) number of spicules per sponge D) number of choanocytes per sponge

Most cnidarians are known to produce toxins. In fact, it has been claimed that one particular species produces the most deadly of all toxins on the planet. What feature of this group most likely evolved simultaneously with the evolution of these toxins? A) the medusa body form B) asexual reproduction C) a slow-moving or sessile lifestyle in the adult D) diploblastic design

Healthy corals are brightly colored because they _____. A) secrete colorful pigments to attract mates B) host symbionts with colorful photosynthetic pigments C) build their skeletons from colorful minerals D) secrete colorful pigments to protect themselves from ultraviolet light

In terms of food capture, which sponge cell is most similar to the cnidocyte of a cnidarian? A) amoebocyte B) choanocyte C) epidermal cell D) pore cell

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 actually provides nutrition to the sea star, and which chemical (besides the toxin within their nematocysts) do the corals rely on for protection? A) medusae; silica B) exoskeleton; calcium carbonate C) polyps; calcium carbonate D) polyps; silica

An elementary school science teacher decided to liven up the classroom with a saltwater aquarium. Knowing that saltwater aquaria can be quite a hassle, the teacher proceeded stepwise. First, the teacher conditioned the water. Next, the teacher decided to stock the tank with various marine invertebrates, including a polychaete, a siliceous sponge, several bivalves, a shrimp, several sea anemones of different types, a colonial hydra, a few coral species, an ectoproct, a sea star, and several herbivorous gastropod varieties. Lastly, she added some vertebrates—a parrotfish and a clownfish. She arranged for daily feedings of copepods and feeder fish. One day, Tommy, a student in an undersupervised class of forty fifth graders, got the urge to pet Nemo (the clownfish), who was swimming among the waving petals of a pretty underwater "flower" that had a big hole in the midst of the petals. Tommy giggled upon finding that these petals felt sticky. A few hours later, Tommy was in the nurse's office with nausea and cramps. Microscopic examination of his fingers would probably have revealed the presence of _____. A) teeth marks B) spines C) spicules D) nematocysts

The teacher and class were especially saddened when the colonial hydrozoan died. They had watched it carefully, and the unfortunate creature never even got to produce offspring by budding. Yet, everyone was elated when one of the students noticed a small colonial hydrozoan growing in a part of the tank far from the location of the original colony. The teacher was apparently unaware that these hydrozoans exhibit _____. A) spontaneous generation B) abiogenesis C) alternation of generations D) a medusa stage

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 the most likely alternative would be that this toxin is _____. A) derived from the nematocysts of its prey B) absorbed from the surrounding seawater C) an endotoxin of cellulose-digesting bacteria that inhabit the sea star's digestive glands D) injected into individual thorns by mutualistic corals which live on the aboral surfaces of these sea stars

The presence of a lophophore in a newly discovered species would suggest that the species _____. A) has an exoskeleton B) grows by shedding its external covering C) is motile D) is a suspension feeder

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 flatworm than it is to a roundworm? A) It is a suspension feeder. B) It has no coelom. C) It is shaped like a worm. D) It has a mouth and an anus.

What would be the best anatomical feature to look for to 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) number of shell plates

Which of the following organisms would you expect to have the largest surface-area-to-volume ratio? Assume that all of the following are the same total length. A) a mollusk B) an annelid C) an arthropod D) a platyhelminth

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

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 true coelom. These eggs probably belonged to a(n) _____. A) echinoderm B) mollusc C) nematode D) arthropod

The nontaxonomic term sea slug encompasses a wide variety of marine gastropods. One feature they share as adults is the lack of a shell. We might think, therefore, that they represent defenseless morsels for predators. In fact, sea slugs have multiple defenses. Some sea slugs prey on sponges and concentrate sponge toxins in their tissues. Others feed on cnidarians, digesting everything except the nematocysts, which they then transfer to their own skins. Whereas the most brightly colored sea slugs are often highly toxic, others are nontoxic and mimic the coloration of the toxic species. Their colors are mostly derived from pigments in their prey. There are also sea slugs that use their coloration to blend into their environments. Which structure do sea slugs use to feed on their prey? A) nematocysts B) an incurrent siphon C) a radula D) a mantle cavity

The nematocysts most likely reach the skin of sea slugs through branches of the _____. A) intestine B) excurrent siphon C) nephridium D) pseudocoelom

The nematocysts of sea slugs should be most effective at protecting individual sea slugs from predation if the predators _____. A) remove small bites of flesh from sea slugs and have long-term memory B) remove small bites of flesh from sea slugs and have no long-term memory C) consume entire sea slugs in one gulp and have no long-term memory D) consume entire sea slugs in one gulp and have long-term memory

If the dinoflagellate-containing sea slug P. ianthina preys on coral animals, then it would be LEAST surprising to find that _____. A) P. ianthina has no tolerance to the toxin in the nematocysts of its prey B) P. ianthina can locate its coral prey by chemicals released into the water by corals C) the coral prey harbor dinoflagellates in their tissues D) the coral prey transform themselves into medusas to flee from approaching P. ianthina

The sea slug Elysia chorotica has no nematocysts or dinoflagellates but, rather, has "naked" chloroplasts in its skin. The chloroplasts are all that remain of the seaweed (Vaucheria sp.) that Elysia feeds upon. The chloroplasts are transferred to the skin; consequently, this slug is green. It spends most of its time basking in shallow water on the surface of seaweeds. How should we expect its chloroplasts to benefit the Elysia sea slug? 1. provide Elysia with fixed carbon dioxide 2. provide Elysia with fixed nitrogen 3. provide Elysia with protective coloration A) 1 only B) 2 only C) 3 only D) 1 and 3

Nudibranchs usually have two rhinophores. However, if they had a single rhinophore, it could still carry out the function of two rhinophores, and with similar effectiveness, if this single rhinophore _____. A) had two branches, one directed to the left, the other to the right B) was located within the mantle cavity C) was as long as two rhinophores placed end to end D) had cilia whose power strokes directed water away from the surface of the slug

A natural predator of the crown-of-thorns sea star is a mollusc called the Giant Triton, Charonia tritonis. If the triton uses a radula to saw into the sea star, then to which clade should the triton belong? A) chitons B) bivalves C) gastropods D) cephalopods

If the teacher wanted to show the students what a lophophore is and how it works, the teacher would point out a feeding _____. A) hydra B) sponge C) gastropod D) ectoproct

The teacher was unaware of the difference between suspension feeding and predation. The teacher thought that providing live copepods (2 mm long) and feeder fish (2 cm long) would satisfy the dietary needs of all of the organisms. Consequently, which two organisms would have been among the first to starve to death (assuming they lack photosynthetic endosymbionts)? A) sponges and corals B) sea stars and sponges C) shrimp and bivalves D) bivalves and sponges

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