Life: The Science of Biology

David E. Sadava, David M. Hilliss, H. Craig Heller,May Berenbaum

Chapter 46

Sensory Systems - all with Video Answers

Educators

Chapter Questions

Problem 1

Which statement about sensory systems is not true?
a. Sensory transduction involves the conversion (direct or indirect) of a physical or chemical stimulus into changes in membrane potentials.
b. In general, a stimulus causes a change in the flow of ions across the plasma membrane of a sensory receptor cell.
c. The term "adaptation" refers to the process by which a sensory system becomes insensitive to a continuing source of stimulation.
d. The more intense a stimulus, the greater the magnitude of each action potential fired by a sensory neuron.
e. Sensory adaptation plays a role in the ability of organisms to discriminate between important and unimportant information.

Precious

Precious

Numerade Educator

Problem 2

The female silkworm moth releases a chemical called bombykol from a gland at the tip of her abdomen. Bombykol is
a. a sex hormone.
b. detected by the male only when present in large quantities.
c. not species-specific.
d. detected by hairs on the antennae of male silkworm moths.
e. a chemical basic to the taste process in arthropods.

Katie Haasch

Numerade Educator

Problem 3

Which statement about olfaction is not true?
a. In general, mammals depend more on vision than on olfaction as their dominant sensory modality.
b. Olfactory stimuli are recognized by the interaction between odorant molecules and receptor proteins on olfactory hairs.
c. The more odorant molecules that bind to receptors, the more action potentials are generated.
d. The greater the number of action potentials generated by an olfactory receptor, the greater the intensity of the perceived smell.
e. The perception of different smells results from the activation of different combinations of olfactory receptors.

Precious

Numerade Educator

Problem 4

In general, the touch receptors located close to the surface of both hairy and nonhairy skin
a. are relatively insensitive to light touch.
b. adapt very quickly to stimuli.
c. are uniformly distributed throughout the surface of the body.
d. are called Pacinian corpuscles.
e. adapt slowly and provide almost continuous information.

Katie Haasch

Numerade Educator

Problem 5

The membrane that is most directly responsible for the ability to discriminate different pitches of sound is the
a. round window.
b. oval window.
c. tympanic membrane.
d. tectorial membrane.
e. basilar membrane.

Alexander Cheng

Alexander Cheng

Numerade Educator

Problem 6

Which statement is not true?
a. The transmembrane potential of a rod cell becomes more negative when the rod cell is exposed to light.
b. A photoreceptor releases the most neurotransmitter when in total darkness.
c. Whereas in vision the intensity of a stimulus is encoded by the degree of hyperpolarization of photoreceptors, in hearing the intensity of a stimulus is encoded by changes in firing rates of sensory neurons.
d. Stiffening of the ossicles in the middle ear can lead to deafness.
e. The interaction among hammer (malleus), anvil (incus), and stirrup (stapes) conducts sound waves across the fluid-filled middle ear.

Precious

Numerade Educator

Problem 7

In humans, the region of the retina where the central part of the visual field falls is the
a. central ganglion cell.
b. fovea.
c. optic nerve.
d. cornea.
e. pupil.

Katie Haasch

Numerade Educator

Problem 8

Which of the following statements about information flow in the vertebrate visual system is true?
a. Action potentials in bipolar cells cause the release of neurotransmitter onto ganglion cells.
b. Amacrine cells integrate the activity of neighboring rod and cone cells.
c. When photons of light enter they eye, the first cells in the retina they encounter are ganglion cells.
d. The highest density of rod cells in the human retina is centrally located in the fovea, resulting in high acuity dim light vision.
e. Pigmented epithelial cells at the back of the retina provide information about the level of ambient light for contrast adjustments.

Katie Haasch

Numerade Educator

Problem 9

Which statement about the cone cells in a human eye is not true?
a. They are responsible for our sharpest vision.
b. They are responsible for color vision.
c. They are more sensitive to light than rods are.
d They are fewer in number than rods.
e. They exist in high numbers at the fovea.

Katie Haasch

Numerade Educator

Problem 10

The color in color vision results from the
a. ability of each cone cell to absorb all wavelengths of light equally.
b. lens of the eye acting like a prism and separating the different wavelengths of light.
c. differential absorption of wavelengths of light by different kinds of rod cells.
d. three different isomers of opsin in cone cells.
e. absorption of different wavelengths of light by amacrine and horizontal cells.

Katie Haasch

Numerade Educator