Exam 33: Invertebrates

The water vascular system of echinoderms

Which of the following statements about tapeworm feeding methods is correct?

Which molluscan class includes marine organisms whose shell consists of eight plates?

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)

The following questions refer to the paragraph below. An elementary school science teacher decided to liven up the classroom with a salt-water aquarium. Knowing that salt-water 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 gastropod varieties. Lastly, some vertebrates-a parrotfish and a clownfish-were added. She arranged for daily feedings of copepods and feeder fish. -Had the teacher wanted to point out organisms that belong to the most successful animal phylum, the teacher should have chosen the 1. bivalves. 2) sea anemones. 3) shrimp. 4) polychaete. 5) copepods.

The following questions refer to the paragraph below. An elementary school science teacher decided to liven up the classroom with a salt-water aquarium. Knowing that salt-water 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 gastropod varieties. Lastly, some vertebrates-a parrotfish and a clownfish-were added. She arranged for daily feedings of copepods and feeder fish. -The species in the aquarium that possess True bilateral symmetry include the 1. sponges. 2) molluscs. 3) echinoderm. 4) sea anemones. 5) ectoprocts.

The members of which class of the phylum Cnidaria occur only as polyps?

What would be the most effective method of reducing the incidence of blood flukes in a human population?

An organism is able to extend its feeding structure(s)through a hole in its body wall. If the organism were a sea star, it would extend its

A brachiopod can be distinguished from a bivalve by the presence of

Which of the following is a characteristic of adult echinoderms?

The following questions refer to the paragraph below. A farm pond, usually dry during winter, has plenty of water and aquatic pond life during the summer. One summer, Sarah returns to the family farm from college. Observing the pond, she is fascinated by some six-legged organisms that can crawl about on submerged surfaces or, when disturbed, seemingly "jet" through the water. Watching further, she is able to conclude that the "mystery organisms" are ambush predators, and their prey includes everything from insects to small fish and tadpoles. -A stalked, sessile marine organism has several feathery feeding structures surrounding an opening through which food enters. The organism could potentially be a cnidarian, a lophophorate, a tube-dwelling worm, a crustacean, or an echinoderm. Finding which of the following in this organism would allow the greatest certainty of identification?

What distinguishes complete metamorphosis from incomplete metamorphosis in insects?

Which of the following have a mouth that is directed upward?

The following questions refer to the paragraph below. A farm pond, usually dry during winter, has plenty of water and aquatic pond life during the summer. One summer, Sarah returns to the family farm from college. Observing the pond, she is fascinated by some six-legged organisms that can crawl about on submerged surfaces or, when disturbed, seemingly "jet" through the water. Watching further, she is able to conclude that the "mystery organisms" are ambush predators, and their prey includes everything from insects to small fish and tadpoles. -Sarah had learned that ancestral (Carboniferous era)dragonfly species were much larger than extant dragonfly species are, with wingspans of 70 cm. This struck her as odd, because she had also learned that one of the things that keeps insects small is their relatively inefficient respiratory system. Which two hypotheses might help account for the large size of ancestral dragonflies? 1) If the atmosphere during the Carboniferous had featured a higher oxygen content than the modern atmosphere, then tracheae might have been sufficient means for oxygen delivery to the interior tissues. 2) If large size was a drawback, then the large dragonflies underwent extinction, which explains why all extant dragonflies are smaller. 3) If the ancestral dragonflies had possessed muscles that permitted effective ventilation of the tracheae, then the tracheae might have been sufficient means for oxygen delivery to the interior tissues. 4) If ancestral dragonflies existed during greenhouse conditions, then they must have survived by decreasing their activity levels, no longer capturing prey in flight. Thus, for them, an ineffective respiratory system was sufficient.

A student observes a worm-like organism crawling about on dead organic matter. Later, the organism sheds its outer covering. One possibility is that the organism is a larval insect (like a maggot). On the other hand, it might be a member of which phylum, and one way to distinguish between the two possibilities is by looking for the presence of

Which molluscan class includes members that undergo embryonic torsion?

One should expect to find the "9 + 2 pattern" of microtubules in association with the feeding apparatus of which of the following?