Deck 46: Sensory Systems

Question 1

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.

Answer 1

D

Question 2

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.

Answer 2

D

Question 3

Which anatomical adaptation allows bats to hear the echoes of their high-pitched sound pulses?

A) A pit organ in front of their eyes
B) Fatty deposits surrounding their jaw
C) Small muscles that adjust their hearing sensitivity
D) Membranes of their wings that vibrate in response to the echoes
E) None of the above

Answer 3

C

Question 4

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.

Question 5

Which of the following statements regarding the stimulation of receptor proteins within plasma membranes is true?

A) The receptor proteins of mechanoreceptors and thermoreceptors are themselves the ion channels.
B) The receptor proteins of chemoreceptors and photoreceptors initiate biochemical cascades that eventually open and close ion channels.
C) Receptor proteins are integral to the sensory process.
D) Both a and b
E) All of the above

Question 6

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.

Question 7

The advantage of communicating by means of extremely low-frequency sound waves is that

A) it permits coordination of attacks on prey.
B) these waves travel a very long distance.
C) the echoes of these waves bouncing back help locate prey.
D) the echoes of these waves bouncing back help in navigation.
E) All of the above

Question 8

Receptor potentials produce action potentials in two ways: by generating action potentials within the sensory cells, or by causing the release of _______, which induces an associated neuron to generate action potentials.

A) a hormone
B) ATP
C) interleukin
D) a neurotransmitter
E) glucagon

Question 9

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.

Question 10

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.

Question 11

Which of the following are ionotropic sensory receptors?

A) Mechanoreceptors
B) Thermoreceptors
C) Electroreceptors
D) Both a and b
E) All of the above

Question 12

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.

Question 13

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.

Question 14

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.

Question 15

Humans are unable to see the _______ region of the electromagnetic radiation spectrum.

A) infrared
B) orange
C) green
D) violet
E) None of the above; humans can see all of these regions.

Question 16

Which of the following are not metabotropic sensory receptors?

A) Chemoreceptors
B) Photoreceptors
C) Thermoreceptors
D) All of the above are metabotropic sensory receptors.
E) None of the above are metabotropic sensory receptors.

Question 17

In general, _______ are cells of the nervous system that transduce physical or chemical stimuli into signals that are transmitted to other parts of the nervous system for processing and interpretation.

A) sensory cells
B) effectors
C) glial cells of the blood-brain barrier
D) nuclei within the midbrain
E) None of the above

Question 18

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.

Question 19

Which of the following likely have no receptor protein associated with them?

A) Electrosensors
B) Mechanoreceptors
C) Thermoreceptors
D) Chemoreceptors
E) Photoreceptors

Question 20

Sensory cells transduce physical or chemical stimuli

A) from one form to another.
B) into a change of membrane potential.
C) from an action potential into a synaptic signal.
D) by summing incoming action potentials.
E) into different forms to be sent to the brain.

Question 21

The magnitude of a receptor potential

A) depends on the strength of the incoming action potential.
B) remains high even after a long period of stimulation.
C) is the same no matter what the type of stimulus.
D) depends on the amount of neurotransmitter released.
E) affects the frequency of resulting action potentials.

Question 22

Approximately how many genes code for olfactory receptor proteins in mice?

A) 14
B) 120
C) 1,000
D) 10,000
E) An unknown number; this question has never been studied.

Question 23

One of the best-studied examples of chemosensory receptors is Bombyx mori, a member of the _______ group.

A) cephalopod
B) arthropod
C) chordate
D) ctenophore
E) annelid

Question 24

Which of the following represents the correct order of the flow of information in a stretch receptor that generates an action potential?

A) Stimulus, ion channel, action potential, receptor protein, neurotransmitter release
B) Stimulus, neurotransmitter release, action potential, ion channel, receptor protein
C) Stimulus, receptor protein, ion channel, action potential, neurotransmitter release
D) Stimulus, action potential, neurotransmitter release, receptor protein, ion channel
E) Stimulus, receptor protein, action potential, neurotransmitter release, ion channel

Question 25

Which of the following statements about a sensory cell is false?

A) It is specialized for detecting specific kinds of stimuli.
B) It transduces energy into action potentials.
C) It generates receptor potentials, which travel long distances.
D) It can generate action potentials.
E) It can become insensitive to a source of continuous stimulation.

Question 26

Which of the following statements about receptor potentials is false?

A) They can cause the release of a neurotransmitter.
B) They can cause an action potential.
C) They are a change in membrane potential of the sensory cell.
D) They can spread over long distances.
E) They can be amplified.

Question 27

Which of the following are metabotropic sensory receptors?

A) Chemoreceptors
B) Photoreceptors
C) Thermoreceptors
D) Both a and b
E) All of the above

Question 28

The smell of baking bread triggers

A) an ionotropic sensory receptor.
B) the opening of a cation channel.
C) a metabotropic sensory receptor.
D) a second messenger system.
E) Both c and d

Question 29

If you brush against a doorway as you enter a room, you will trigger

A) an ionotropic sensory receptor.
B) the opening of a pressure-sensitive cation channel.
C) a metabotropic sensory receptor.
D) a second messenger system.
E) Both a and b

Question 30

Chemoreceptors

A) are possessed by all animals.
B) can cause strong behavioral responses.
C) do not undergo adaptation.
D) Both a and b
E) All of the above

Question 31

Bright light shining directly into one's eye will trigger

A) an ionotropic sensory receptor.
B) the opening of a cation channel.
C) a metabotropic sensory receptor.
D) a second messenger system.
E) Both c and d

Question 32

Pheromones are chemical signals that can signal from _______ to _______.

A) one neuron; another
B) the peripheral nervous; the central nervous system
C) prey; predator
D) parasite; host
E) female; male within a species

Question 33

Which of the following statements about sensory cells is false?

A) Most sensory cells are modified neurons.
B) Sensory cells can respond equally to all types of stimuli.
C) Changes in stimulus strength lead to changes in a sensory cell's receptor potential.
D) Sensory cells display a phenomenon called adaptation.
E) Some are assembled with other cell types that enhance the sensory cells' ability to collect, filter, and amplify stimuli.

Question 34

Which of the following are not mechanoreceptors?

A) Stretch receptors
B) Hair cells
C) Pressure receptors
D) Olfactory receptors
E) Airflow receptors

Question 35

Which of the following behaviors results from the adaptation of sensory cells?

A) Going into a deep sleep
B) Discriminating different colors
C) Ignoring your shoes as you walk
D) Detecting high-pitched notes
E) Detecting sound and light simultaneously

Question 36

The sound of the alarm clock in the morning triggers _______ in the sleeper.

A) an ionotropic sensory receptor
B) the opening of a pressure-sensitive cation channel
C) a metabotropic sensory receptor
D) a second messenger system
E) Both a and b

Question 37

Which of the following are not ionotropic sensory receptors?

A) Mechanoreceptors
B) Thermoreceptors
C) Chemoreceptors
D) Electroreceptors
E) All of the above are ionotropic sensory receptors.

Question 38

What percentage of the mouse genome codes for olfactory receptor proteins?

A) 0.02%
B) 1%
C) 0.3%
D) 3%
E) 14%

Question 39

The warmth of the sun on one's face triggers

A) an ionotropic sensory receptor.
B) the opening of a cation channel.
C) a metabotropic sensory receptor.
D) a second messenger system.
E) Both a and b

Question 40

As a male silkworm moth nears a female that is releasing bombykol,

A) the female starts to release more bombykol.
B) the action potentials in the antennal nerve increase.
C) many bombykol-sensitive hairs are stimulated per second.
D) a larger number of the bombykol-sensitive hairs undergo adaptation.
E) the receptor potential in bombykol-sensitive hairs is reduced.

Question 41

Hair cells in the ear that give auditory information are concentrated in the

A) oval window.
B) tympanic membrane.
C) organ of Corti.
D) semicircular canals.
E) vestibular apparatus.

Question 42

Which of the following most accurately describes the Pacinian corpuscle?

A) It adapts slowly and provides information about vibrating stimuli of low frequency.
B) It responds to extended, steady pressure.
C) It adapts rapidly and provides information about vibrating stimuli of high frequency.
D) It has long, extensive dendritic processes.
E) It is extremely sensitive to light touch.

Question 43

When a female sable antelope smells the urine of another female, a sample of nasal fluid is drawn over chemoreceptors of the _______, which is a structure located on the septum dividing the two nostrils.

A) gustatory nucleus
B) fovea
C) vomeronasal organ
D) organ of Corti
E) loop of Henle

Question 44

Action potentials are generated in a mechanoreceptor when

A) ion channels close in response to membrane distortion.
B) ion channels open in response to membrane distortion.
C) receptors bind chemicals in response to pressure.
D) sensitivity of the membrane to neurotransmitters increases.
E) signals from other mechanoreceptors are summated.

Question 45

Hair cells are associated with all of the following sensory systems except the

A) Golgi tendon organ.
B) lateral line.
C) cochlea.
D) vestibular apparatus.
E) semicircular canals.

Question 46

The auditory function of the middle ear is to convert _______ pressure waves into _______.

A) air; fluid pressure waves
B) fluid; air pressure waves
C) air; nerve impulses
D) fluid; nerve impulses
E) air; hair cell movements

Question 47

A male silkworm moth locates a female at a distance by

A) flying toward a chemical signal.
B) flying toward a sound signal.
C) flying toward anything shaped like a female moth.
D) emitting a sound as the female approaches.
E) emitting a chemical as the female approaches.

Question 48

Which of the following statements about the auditory functioning of the cochlea is false?

A) The flexing of the round window follows the flexing of the oval window in a delayed fashion.
B) The hair cells on the organ of Corti move against the rigid tectorial membrane.
C) The intensity of the sound determines how many hair cells will be stimulated.
D) The frequency of the sound determines which hair cells will be stimulated.
E) Lower frequency sounds result in the stimulation of hair cells closer to the round window.

Question 49

The chemosensory hairs with which male moths detect a female's pheromones are located

A) near the mouthparts.
B) at the base of the wings.
C) on the tip of the proboscis.
D) on the antennae.
E) on the feet.

Question 50

Which of the following events is triggered by the binding of an odorant molecule to a receptor protein?

A) Opening of sodium channels
B) Increase of second messenger in cytoplasm of sensory cell
C) Activation of G protein
D) Depolarization of sensory cell
E) All of the above

Question 51

Which of the following statements about mechano-receptors is false?

A) Mechanoreceptors transduce mechanical forces into changes in receptor potential.
B) If a mechanoreceptor is subject to increased distortion, more ion channels within its membrane open.
C) Most mechanoreceptors are metabotropic sensory receptors.
D) If the receptor potential of a mechanoreceptor rises above a threshold, an action potential is propagated.
E) Stimulus strength determines the rate of generated action potentials.

Question 52

The Golgi tendon organ

A) causes muscles to relax and protects against tearing.
B) senses light touch.
C) increases muscle contraction.
D) is found in high densities on lips and fingertips.
E) provides steady-state information about pressure.

Question 53

Which of the following structures of the mammalian auditory system is involved in transduction of pressure changes into action potentials?

A) Tympanic membrane
B) Ear ossicles
C) Oval window
D) Organ of Corti
E) Basilar membrane

Question 54

Compared to humans, dogs have a much more acute sense of smell due to the

A) larger amount of mucus in their noses.
B) larger surface area of their nasal epithelia.
C) greater density of their olfactory nerve endings.
D) larger number of capillaries in their noses.
E) typical canine body temperature.

Question 55

Meissner's corpuscles

A) adapt very slowly.
B) are present uniformly on skin surfaces.
C) sense pressure.
D) have concentric layers of connective tissue.
E) sense light touch.

Question 56

Which of the following structures of the mammalian auditory system is responsible for transmitting signals between flexible membranes?

A) Organ of Corti
B) Ear ossicles
C) Oval window
D) Cochlea
E) Round window

Question 57

Which of the following receptors are located deep in the skin and are adapted specifically for sensing pressure?

A) Meissner's corpuscles
B) Pacinian corpuscles
C) Expanded-tip tactile receptors
D) Neuron-wrapped hair follicles
E) Bare nerve endings

Question 58

Which of the following statements about gustation is false?

A) Taste receptors may be either ionotropic or metabotropic.
B) All stimulated taste sensory neurons respond by generating an action potential.
C) Microvilli increase the surface area of taste sensory cells.
D) Individual taste buds are replaced every few months.
E) Taste sensory cells form synapses with dendrites of sensory neurons.

Question 59

What is the physiological basis for the auditory system's ability to distinguish different sound frequencies?

A) The three bones of the middle ear respond differentially.
B) The loops of the semicircular canals respond differentially.
C) The oval window and round window respond differentially.
D) Different sections of the basilar membrane respond differentially.
E) Individual hair cells have different peak frequency responses.

Question 60

The greatest intensity of perceived smell comes from the

A) enzyme that binds with the most odorant molecules.
B) odorant that binds to the most receptors.
C) greatest variety of odorant molecules.
D) greatest threshold of depolarization.
E) greatest number of odorant molecules entering the cell.

Question 61

Stereocilia in hair cells in the canals of the fish lateral line

A) respond to disturbances in the water around the fish.
B) are moved individually by pressure.
C) are immobilized within a cupula.
D) bend only after electrical stimulation.
E) bend under the influence of gravity.

Question 62

The molecular mechanism by which light is absorbed into visual systems is

A) a change of shape in the opsin protein.
B) depolarization of the rhodopsin molecule.
C) isomerization of the retinal molecule.
D) oxidation of the rhodopsin molecule.
E) None of the above

Question 63

Arthropods have evolved compound eyes consisting of large numbers of

A) retinas.
B) cones.
C) eye cups.
D) ommatidia.
E) pupils.

Question 64

Which of the following is a difference between rods and cones?

A) Cones are more sensitive at low light intensity.
B) Rods are responsible for color vision.
C) There are more cones than rods in the human retina.
D) Strictly nocturnal animals have more cones than rods.
E) In the fovea, the density of cones is greater than the density of rods.

Question 65

Which of the following statements about the functioning of the vertebrate eye is false?

A) The cornea is transparent so that it can transmit light.
B) The size of the pupil varies with light levels.
C) The iris is under control of the autonomic nervous system.
D) The lens focuses the image on the retina.
E) The fovea is the part of the retina with the lowest density of photoreceptors.

Question 66

The amount of light entering the eye is decreased when the

A) distance between the lens and retina is decreased.
B) distance between the lens and retina is increased.
C) iris relaxes.
D) iris constricts.
E) shape of the lens changes.

Question 67

Which of the following statements about the molecular events of photoreception is false?

A) A single photon can excite a rhodopsin molecule.
B) In a well-lit setting, most of the sodium channels of a rod cell are open.
C) cGMP keeps the sodium channels open.
D) Activated phosphodiesterase (PDE) catalyzes the reaction hydrolyzing cGMP into GMP.
E) Activated transducin activates PDE.

Question 68

Which of the following statements about the compound eyes of arthropods is false?

A) Ommatidia are the optical units of compound eyes.
B) The number of ommatidia per eye can vary greatly in different species.
C) The eyes of cephalopods are similar to the compound eyes of arthropods.
D) The compound eye communicates a relatively crude image to the central nervous system.
E) Each ommatidium has a lens structure that directs light onto photoreceptors.

Question 69

Which of the following statements about rhodopsin is false?

A) Rhodopsin consists of a protein and a light-absorbing molecule.
B) When 11-cis-retinal absorbs light, it becomes all-trans-retinal.
C) In vertebrate eyes, the retinal and the opsin never separate from each other.
D) Rhodopsin is a transmembrane protein.
E) All animals that can sense light do so using rhodopsin.

Question 70

When an individual rod cell is stimulated with light, its membrane potential

A) becomes more negative.
B) becomes more positive.
C) becomes more positive than that of other neurons.
D) begins to generate action potentials.
E) begins to reduce membrane polarization.

Question 71

Which of the following statements about the functioning of a rod cell is false?

A) Rhodopsin is located in the stack of disks that is farthest from the light source.
B) A rod cell is a modified neuron.
C) The resting potential of a rod cell in the dark is less negative than a typical neuron.
D) The membrane potential of a rod cell exposed to light becomes more positive.
E) The plasma membrane of a rod cell is fairly permeable to Na⁺ ions.

Question 72

Which of the following statements about accommodation is false?

A) Accommodation is the process by which objects from different portions of the visual field are focused on the retina.
B) Vertebrates such as fish and reptiles accommodate by moving the lens relative to the retina.
C) The suspensory ligaments keep the lens flattened.
D) When a person attempts to focus on a distant object, the ciliary muscles contract.
E) The ciliary muscles change the shape of the eye by counteracting the action of the suspensory ligaments.

Question 73

If a flatworm is positioned relative to a stationary light source such that more light-sensitive cells are stimulated in its right than in its left eye cup, the planarian will

A) turn to the left.
B) turn to the right.
C) make a complete clockwise circle.
D) make a complete counterclockwise circle.
E) stop moving.

Question 74

When the stereocilia of hair cells are bent, the membranes of the hair cells

A) are depolarized.
B) are hyperpolarized.
C) are either depolarized or hyperpolarized.
D) generate action potentials.
E) contract their stereocilia.

Question 75

Which of the following statements about the lateral line system is true?

A) The cupulae of the lateral line system each contain several hair cells.
B) The lateral line system allows the fish to sense the presence of other fish.
C) The lateral line system responds to pressure waves in the surrounding water.
D) The canal of the lateral line system has numerous openings to the external environment.
E) All of the above

Question 76

Conduction deafness is caused by loss of function of

A) the inner ear.
B) the eustachian tube.
C) the tympanic membrane and the middle ear ossicles.
D) hair cells in the organ of Corti.
E) the cochlea.

Question 77

Which of the following sensory structures provides mammals with information about the position and orientation of the head?

A) Eustachian tube
B) Cochlea
C) Semicircular canal
D) Lateral line
E) Tympanic membrane

Question 78

Which of the following does not affect the focus of an image on the retina?

A) The shape of the lens
B) The shape of the retina
C) The ligaments suspending the lens
D) The ciliary muscles
E) The elasticity of the lens

Question 79

Which of the following statements about vertebrate vision is false?

A) Visual acuity varies according to the density of photoreceptors in the retina.
B) Some vertebrates have two foveas per eye.
C) A blind spot is always located where the optic nerve leaves the eye.
D) Unlike a camera, the vertebrate eye does not project inverted images on the retina.
E) Two major types of photoreceptor cells are found in the retina.

Question 80

The activation of a rhodopsin molecule sets off a chain reaction that leads to the

A) opening of a sodium channel.
B) closing of a large number of sodium channels.
C) formation of an activated phosphodiesterase molecule.
D) activation of a large number of transducin molecules.
E) activation of other rhodopsin molecules.