What are the cells in a sponge that are primarily responsible for trapping food particles from circulating water?
Which class of the phylum Cnidaria includes "jellies" with rounded (as opposed to box-like medusae?
Which characteristic is shared by both cnidarians and flatworms?
a digestive system with a single opening
What would be the most effective method of reducing the incidence of blood flukes in a human population?
The larvae of many common tapeworms affecting humans are usually found
encysted in the muscle of an animal such as a cow or pig.
While vacationing in a country that lacks adequate meat inspection, a student ate undercooked ground beef. Sometime later the student became easily fatigued, and lost body weight. At about the same time, whitish, flattened, rectangular objects full of small white spheres started appearing in his feces. Administration of niclosamide cured the problem. The student had probably been infected by a
Which of the following combinations of phylum and description is incorrect?
Porifera-gastrovascular cavity, coelom present
An organism is able to extend its feeding structure(s) through a hole in an exoskeleton. If the organism were an ectoproct, it would extend a ________; if a coral animal, it would extend ________; if a bivalve, it would extend ________; and if a barnacle, it would extend ________.
While sampling marine plankton in a lab, a student encounters large numbers of fertilized eggs. She 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. These eggs probably belonged to a(n)
In a tide pool, a student encounters an organism with a hard outer covering that contains much calcium carbonate, an open circulatory system, and gills. The organism could potentially be a crab, a shrimp, a barnacle, or a bivalve. Which structure below would allow for the most certain identification?
While snorkeling, a student observes an active marine animal that has a series of muscular tentacles bearing suckers associated with its head. Segmentation is not observed, but a pair of large, well-developed eyes is evident. The student is observing an animal belonging to which class?
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?
a water vascular system
A terrestrial animal species is discovered with the following larval characteristics: exoskeleton, tracheal system for gas exchange, and modified segmentation. A knowledgeable zoologist would predict that its adults probably also would have
an open circulatory system
What is true of echinoderms?
They have an endoskeleton of hard calcareous plates. Tube feet provide motility in most
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 the phylum ________. One way to distinguish between the two possibilities is by looking for the presence of
Nematoda; a circulatory system
The heartworms that can accumulate within the heart of dogs and other mammals have a pseudocoelom, an alimentary canal, and an outer covering that is occasionally shed. To which phylum does the heartworm belong?
Skeletal structures that are entirely or partly composed of calcium carbonate can be found in some members of the following except
What distinguishes complete metamorphosis from incomplete metamorphosis in insects?
radically different appearance between adults and earlier life stages
A shared derived characteristic for members of the arthropod subgroup that includes spiders would be the presence of
You find a small animal with eight legs crawling up your bedroom wall. Closer examination will probably reveal that this animal has
While working in your garden, you discover a worm-like, segmented animal with two pairs of jointed legs per segment. The animal is probably a
They can extend the stomach through their mouth to feed
A. class Crinoidea (sea lilies and feather stars)
B. class Asteroidea (sea stars)
C. class Ophiuroidea (brittle stars)
D. class Echinoidea (sea urchins and sand dollars)
E. class Holothuroidea (sea cucumbers)
protostomes that have an open circulatory system and an exoskeleton of chitin