What type of sensory system do migrating birds use to detect direction?

Which of these statements about taste is true?

a. Sweetness is a measure of the concentration of hydrogen ions in food.

b. Sodium ions from foods can directly depolarize certain taste cells.

c. All bitter-tasting compounds have a similar chemical structure.

d. Sourness is detected when hydrogen ions bind to membrane receptors.

The human brain differentiates tastes from smells because action potentials for the two sensations differ in

a. Magnitude and shape.

b. Threshold potential.

c. Where they are received in the brain.

d. How long they take to reach the brain.

Which sensory distinction is not encoded by a difference in neuron identity?

a. White and red

b. Red and green

c. Loud and faint

d. Salty and sweet

What do the receptor cells in the lateral line system along the sides of a shark and the cochlea of your ear have in common?

a. They use hair cells to sense sound or pressure waves.

b. They are organs of equilibrium.

c. They use electromagnetic receptors to sense pressure waves in fluid.

d. They use granules that signal a change in position and stimulate their receptor cells.

The transduction of sound waves into action potentials occurs

a. In the tectorial membrane as it is stimulated by hair cells

b. When hair cells are bent against the tectorial membrane, causing them to depolarize and release neurotransmitter that stimulates sensory neurons

c. As the basilar membrane vibrates at different frequencies in response to the varying volume of sounds

d. Within the middle ear as the vibrations are amplified by the malleus, incus, and stapes

If you look away from this book and focus your eyes on a distant object, the eye muscles _________ and the lenses _________ to focus images on the retinas.

a. Relax . . . Flatten

b. Relax . . . Become more rounded

c. Contract . . . Flatten

d. Contract . . . Become more rounded

Considering that sounds and odors both trigger changes in the patterns of action potentials in sensory neurons, how does the brain perceive which sense is which when the action potentials reach the brain?

a. The action potentials stimulated by sounds are different in size and shape from those stimulated by odors.

b. The axons from different sensory neurons go to different areas of the brain.

c. Mechanoreception is not consciously perceived by the brain, whereas chemoreception is.

d. Chemoreception is not consciously perceived by the brain, whereas mechanoreception is.