Most of the exchange surfaces of multicellular animals are lined with

Most of the exchange surfaces of multicellular animals are lined with

A) connective tissue.
B) smooth muscle cells.
C) neural tissue.
D) epithelial tissue.
E) adipose tissue.




Answer: D

The absorptive epithelia in the gut are considered "polarized" because

The absorptive epithelia in the gut are considered "polarized" because

A) thick and thin filaments are present.
B) they pump wastes into the lumen while pumping nutrients toward the blood.
C) the colors seen on the top and bottom of the cells are different.
D) they must fire action potentials to absorb most nutrients.
E) the structures on the apical surface are different than those on the basal surface.

Answer: E

Of the following choices, the epithelium with the shortest diffusion distance is

Of the following choices, the epithelium with the shortest diffusion distance is

A) simple squamous epithelium.
B) simple cuboidal epithelium.
C) simple columnar epithelium.
D) pseudostratified ciliated columnar epithelium.
E) stratified squamous epithelium.

Answer: A

An exchange surface in direct contact with the external environment is found in the

An exchange surface in direct contact with the external environment is found in the

A) lungs.
B) skeletal muscles.
C) liver.
D) heart.
E) brain.




Answer: A

Tissues are composed of cells, and tissues functioning together make up

Tissues are composed of cells, and tissues functioning together make up

A) organs.
B) membranes.
C) organ systems.
D) organelles.
E) organisms.

Answer: A

Multicellular organisms must keep their cells awash in an "internal pond" because

Multicellular organisms must keep their cells awash in an "internal pond" because

A) their membranes will crystallize if not in contact with interstitial fluid.
B) an aqueous medium is needed for the cellular exchange of nutrients, gases, and wastes.
C) this prevents the loss of water due to osmosis.
D) their cells need to be protected from dissolved nitrogen gas in the blood.
E) terrestrial organisms have not adapted to life in dry environments.

Answer: B

Interstitial fluid is

Interstitial fluid is

A) the fluid inside the gastrovascular cavity of Hydra.
B) the internal environment inside animal cells.
C) identical to the composition of blood.
D) the route for the exchange of materials between blood and body cells.
E) found only in the lumen of the small intestine.

Answer: D

The specialized function shared by the cells that line the lungs and those that line the lumen of the gut is that both types of cells

The specialized function shared by the cells that line the lungs and those that line the lumen of the gut is that both types of cells

A) receive their oxygen directly from inhaled air and ingested foods.
B) provide abundant exchange surface.
C) have exceptionally high numbers of cellular organelles in the cytoplasm.
D) offer greater protection due to increased membrane thickness.
E) have a lowered basal metabolic rate due to cooperative exchange between cells.

Answer: B

To increase the effectiveness of exchange surfaces lining the lungs and the intestines, evolutionary pressures have

To increase the effectiveness of exchange surfaces lining the lungs and the intestines, evolutionary pressures have

A) increased the exchange surface area with folds and branches.
B) increased the thickness of the membranes in these linings.
C) increased the number of cell layers in these linings.
D) decreased the metabolic rate of the cells in these linings.
E) increased the volume of the cells in these linings.

Answer: A

As body size increases in animals,

As body size increases in animals,

A) there is a decrease in the surface-to-volume ratio.
B) reproduction becomes limited to terrestrial environments.
C) there is greater variability in metabolic rate.
D) migration to tropical areas becomes necessary for thermoregulation.
E) it becomes more difficult to conserve body warmth in cold environments.

Answer: A

All animals, whether large or small, have

All animals, whether large or small, have

A) an external body surface that is dry.
B) a basic body plan that resembles a two-layered sac.
C) a body surface covered with hair to keep them warm.
D) the ability to enter dormancy when resources become scarce.
E) each living cell in contact with an aqueous medium.

Answer: E

The specialized structures of complex animals have evolved because

The specialized structures of complex animals have evolved because

A) the environment imposes identical problems regardless of where the animals are found.
B) the development of the specialized structures in an animal is influenced by the animal's ability to learn.
C) the simplest animals are those with the most recent appearance among the biota.
D) they permit adjustments to a wide range of environmental changes.
E) the most complex animals are the ones with the most ancient evolutionary origin.

Answer: D

The similar fusiform body shape of diverse animals, such as sharks, penguins, and aquatic mammals, has evolved because

The similar fusiform body shape of diverse animals, such as sharks, penguins, and aquatic mammals, has evolved because

A) natural selection typically has no limits when different organisms face the same challenge.
B) respiration through gills is enhanced by having a fusiform shape.
C) this is the body shape that makes it possible for aquatic animals to swim rapidly.
D) the fusiform shape is coded by the same genes in all three types of aquatic animals.
E) all three types evolved from the same ancestral form, which flew in air rather than swam in water.






Answer: C

Evolutionary adaptations that help diverse animals directly exchange matter between cells and the environment include

Evolutionary adaptations that help diverse animals directly exchange matter between cells and the environment include

A) a gastrovascular activity, a two-layered body, and a torpedo-like body shape.
B) an external respiratory surface, a small body size, and a two-cell-layered body.
C) a large body volume; a long, tubular body; and a set of wings.
D) complex internal structures, a small body size, and a large surface area.
E) an unbranched internal surface, a small body size, and thick covering.

Answer: B

Penguins, seals, and tuna have body forms that permit rapid swimming, because

Penguins, seals, and tuna have body forms that permit rapid swimming, because

A) all share a common ancestor at some point in the past.
B) all of their bodies have been compressed since birth by intensive underwater pressures.
C) flying, pregnancy, and gill-breathing all require similar adaptations in form.
D) the shape is a convergent evolutionary solution to the need to reduce drag while swimming.
E) this is the only shape that will allow them to maintain a constant body temperature in water.

Answer: D

Which choice best describes a reasonable mechanism for animal structures becoming better suited over evolutionary time to specific functions?

Which choice best describes a reasonable mechanism for animal structures becoming better suited over evolutionary time to specific functions?

A) Animals that eat the most food become the most abundant.
B) Animals that restrict their food intake will become less abundant.
C) Animals with mutations that give rise to effective structures will become more abundant.
D) Animals with inventions that curtail reproduction will become more abundant.
E) Animals with parents that continually improve their offspring's structures will become more abundant.

Answer: C

If thermoregulation is considered to be a secondary function of the large ears of jackrabbits, then the primary function of the ears is

If thermoregulation is considered to be a secondary function of the large ears of jackrabbits, then the primary function of the ears is

A) to optimize nutrient intake through the thin, permeable surfaces on the ears.
B) to alter the rate of gas exchange, based on the adjustable radius of the ears' blood vessels.
C) to detect predators by using the large size and flexible positioning of the external ears to channel sound waves into the ear canal.
D) to protect offspring from bright sunlight by the positioning of the ears to cast the maximum shadows.
E) to protect against pathogens by having a thick, waxy surface on the ears.

Answer: C

When the temperature of the outside air exceeds their internal body temperature, jackrabbits living in hot, arid lands will

When the temperature of the outside air exceeds their internal body temperature, jackrabbits living in hot, arid lands will

A) dilate the blood vessels in their large ears to transfer more body heat to the environment.
B) constrict the blood vessels in their large ears to reduce transfer of external heat to the blood in their ears.
C) increase motor movements to find a sunny area to maximize heat transfer into their bodies.
D) increase pigmentation in their ears, darkening them to maximize their capacity to take up heat.
E) begin involuntary shivering of their skeletal muscles in order to generate more metabolic heat.

Answer: B

Which of the following characteristics indicates that mollusks are more closely related to arthropods than to chordates?

Which of the following characteristics indicates that mollusks are more closely related to arthropods than to chordates?

A) Presence of a skeleton
B) Type of respiratory structure
C) Pattern of coelom formation
D) Segmentation
E) Symmetry

Answer: B

Many parasitic flatworms have an intermediate host. This indicates that the

Many parasitic flatworms have an intermediate host. This indicates that the

A) flatworms cannot infect humans
B) larval flatworms infect one species, whereas adults infect another species
C) larval flatworms infect only juveniles of a species
D) flatworm adults are microscopic
E) flatworm larvae are parasitic on their parents

Answer: B