Experiments with genetically altered mice showed that the mice would consume abnormally high amounts of bitter-tasting compounds in water after their

Experiments with genetically altered mice showed that the mice would consume abnormally high amounts of bitter-tasting compounds in water after their 

A) hormone receptors for digestive hormones were reduced or eliminated, showing that bitter tastes are reinforced by digestive responses.
B) salt-taste cells were altered to express receptors for bitter tastants, suggesting that animals have unregulated salt appetites.
C) visual sense was reduced or eliminated, suggesting that mice learn visual cues about bitter tastes.
D) olfactory sense was reduced or eliminated, suggesting that mice learn odor cues about bitter tastes.
E) sweet-taste cells were altered to express receptors for bitter tastants, suggesting that the sensation of taste depends only on which taste cell is stimulated.





Answer: E

Among these choices, the most energetically efficient locomotion per unit mass is likely

Among these choices, the most energetically efficient locomotion per unit mass is likely 

A) running by a 50-gram rodent.
B) running by a 40-kg ungulate.
C) flying by a 100-g bird.
D) swimming by a 10-g minnow (bony fish).
E) swimming by a 100-kg tuna (bony fish).





Answer: E

A ball-and-socket joint connects

A ball-and-socket joint connects 

A) the radius to the ulna.
B) the radius to the humerus.
C) the ulna to the humerus.
D) the humerus to the scapula.
E) the radius to the scapula.






Answer: D

An endoskeleton is the primary body support for the

An endoskeleton is the primary body support for the 

A) annelids, including earthworms.
B) insects, including beetles.
C) cartilaginous fishes, including sharks.
D) bivalves, including clams.
E) crustaceans, including lobsters.






Answer: C

Chitin is a major component of

Chitin is a major component of 

A) the skeleton of mammals.
B) the hydrostatic skeletons of earthworms.
C) the exoskeleton of insects.
D) the body hairs of mammals.
E) the skeleton in birds.







Answer: C

The hydrostatic skeleton of the earthworm allows it to move around in its environment by

The hydrostatic skeleton of the earthworm allows it to move around in its environment by 

A) walking on its limbs.
B) crawling with its feet.
C) swimming with its setae.
D) using peristaltic contractions of its circular and longitudinal muscles.
E) alternating contractions and relaxations of its flagellae.






Answer: D

Action potentials in the heart move from one contractile cell to the next via

Action potentials in the heart move from one contractile cell to the next via 

A) chemical synapses using acetylcholine.
B) chemical synapses using norepinephrine.
C) electrical synapses using gap junctions.
D) myelinated motor neurons.
E) non-myelinated motor neurons.





Answer: C