Deck 44: Animal Sensory Systems

Question 1

A salmon follows a scent trail upstream to find its way back to the stream where it hatched. What type of sensory receptor cell would it use?

A) thermoreceptors
B) mechanoreceptors
C) chemoreceptors
D) electroreceptors
E) nociceptors

Answer 1

C

Question 2

The amount of depolarization that occurs in a sound- receptor cell is proportional to the volume loudness) of the sound.

Answer 2

True

Question 3

How could you genetically modify an animal so that it would distinguish more shades of green?

A) Introduce genes for different opsins that respond in the green region of the spectrum.
B) Introduce genes to produce green fluid in the eyeball, because green fluids will not absorb green light.
C) Induce genes to produce a greater number of cone cells in the fovea.
D) Induce increased production of cGMP to increase opening of cGMP- gated sodium channels.

Answer 3

A

Question 4

Partial or complete loss of hearing deafness) can be caused by damage to the

A) axons of the neurons associated with each hair cell that carry information to the brain.
B) hair cells the sensory receptors) in the cochlea.
C) tympanic membrane, or eardrum.
D) A and B apply.
E) All of the above apply.

Question 5

How would the absence of the enzyme photodiesterase PDE) affect vision in the vertebrate eye?

A) The cGMP- gated sodium channels would remain open, glutamate would be continuously discharged at the synapses, and the brain would not detect light absorbed by the rod cells.
B) The lens could not be appropriately adjusted to focus light on the retina, resulting in either nearsightedness or farsightedness.
C) The opsins found in cones would not be differentiated into the red, blue, and green proteins, causing the animals to be colour blind.
D) All of the above answers are correct.

Question 6

Deafness caused by loud sounds often results from damage to which receptor cells?

A) mechanoreceptors
B) electroreceptors
C) nociceptors
D) chemoreceptors
E) thermoreceptors

Question 7

What is the function of sensory receptor cells?

A) to receive a signal from the environment
B) to transduce a signal from the environment
C) to integrate a signal from the environment
D) all of the above
E) A and B only

Question 8

Which type of receptor would you expect to be most abundant in the antennae of a moth?

A) thermoreceptors
B) mechanoreceptors
C) chemoreceptors
D) electroreceptors
E) nociceptors

Question 9

Elephants hear sounds that are too low for humans to hear. This sensitivity is primarily due to the differences in the

A) size and flexibility of the tympanic membrane eardrum).
B) arrangement and shape of the ossicles.
C) size and shape of the outer ear.
D) flexibility of the basilar membrane in the cochlea.
E) All of the above apply.

Question 10

Which type of receptor is involved in sound detection?

A) thermoreceptors
B) mechanoreceptors
C) chemoreceptors
D) electroreceptors
E) nociceptors

Question 11

How would an abnormally large oval window in a mouse affect that animal's hearing?

A) The mouse could detect noise in a much broader range of frequencies.
B) Hearing is not affected by the size of the oval window.
C) The mouse could detect noise at much lower volumes.
D) Hearing ability would be reduced in comparison with normal mice.

Question 12

Hair cells in the vertebrate ear are responsible for transducing sound pressure waves. Ion channels in the hair cell membrane open when

A) light is absorbed by a molecule in the membrane.
B) the membrane is distorted mechanically.
C) a chemical ligand binds to the ion channel.
D) the cell membrane reaches a threshold voltage.

Question 13

Corneal surgery is now routinely performed to improve vision. This surgery

A) improves the circulation of nutrients to the eye.
B) improves the focusing of light onto the retina.
C) increases the amount of light entering the eye.
D) increases the sensitivity of the photoreceptors.
E) answers B and C both apply.

Question 14

If you experimentally reduce the concentration of K⁺ in the extracellular fluid surrounding hair cells in the inner ear, the result would be like which of the following?

A) decreasing the volume of sound reaching the hair cells
B) decreasing the frequency of sound reaching the hair cells
C) increasing the volume of sound reaching the hair cells
D) increasing the frequency of sound reaching the hair cells

Question 15

A person able to hear only high- frequency sounds would probably have which of the following structural problems in the ear?

A) The basilar membrane is stiffened along its entire length.
B) The ear ossicles are abnormally thickened.
C) The tympanum is damaged because of chronic ear infections.
D) All of the above problems could result in inability to detect low- frequency sound.

Question 16

How does the ear allow humans to distinguish the volume of different sounds?

A) Louder sounds cause larger action potentials than softer sounds.
B) Louder sounds cause smaller action potentials than softer sounds.
C) Louder sounds induce a higher frequency of action potentials than softer sounds.
D) Louder sounds induce a lower frequency of action potentials than softer sounds.
E) Answers A and C are both correct.

Question 17

What is the function of the cochlea?

A) to amplify the sound vibrations
B) to collect sound pressure waves
C) to detect the frequency of sounds
D) A and B
E) all of the above

Question 18

Pit vipers can detect and strike in complete darkness because of their ability to detect

A) infrared wavelengths.
B) odours at extremely low concentration.
C) rapid movements.
D) ultraviolet wavelengths.

Question 19

Bat echolocation sonar) is most closely related to which human sensory system?

A) taste
B) touch
C) smell
D) hearing
E) vision

Question 20

How would the vision of a fly be affected if several of the axons extending from the ommatidia of its compound eye were damaged?

A) The fly would be colour blind in the affected eye.
B) The fly's vision would not be affected, because the remaining functional ommatidia can adjust to compensate for the damaged ones.
C) The fly would have reduced resolution in the affected eye.
D) The fly could not detect light in the affected eye.

Question 21

The transduction of sound waves into action potentials by the human ear takes

A) as the basilar membrane becomes more permeable to sodium ions and depolarizes, initiating an action potential in a sensory neuron.
B) within the middle ear as the vibrations are amplified by the malleus, incus, and stapes.
C) as the basilar membrane vibrates at different frequencies in response to the varying volume of sounds.
D) when hair cells are bent against the tectorial membrane, causing them to depolarize and release neurotransmitter that stimulates sensory neurons.
E) within the tectorial membrane as it is stimulated by the hair cells.

Question 22

Rhodopsins are light- sensitive molecules composed of a protein opsin) and a pigment retinal). The opsin portion of rhodopsin is an example of a

A) peripheral protein.
B) phospholipid.
C) polytopic integral membrane protein.
D) monotopic integral membrane protein.

Question 23

In the human retina

A) rod cells require higher illumination for stimulation than do cone cells.
B) rod cells detect short wavelength UV light.
C) cone cells can detect colour, but rod cells cannot.
D) cone cells are more sensitive than rod cells to light.
E) cone cells, but not rod cells, have a visual pigment.

Question 24

What would happen to people exposed to a chemical warfare agent that blocked acetylcholine from binding to muscle receptors?

A) Action potentials would be continuously generated, causing convulsive muscle contractions.
B) Muscle contractions would be prevented, causing paralysis.
C) Muscle contractions could still occur, but relaxation of the muscle would be impaired.
D) Answers A and B both apply.

Question 25

Light reflecting off an object in the environment is detected by photoreceptors after following which path?

A) retina > ganglion cell layer > lens > iris > cornea
B) lens > cornea > retina > ganglion cell layer > iris
C) cornea > lens > iris > ganglion cell layer > retina
D) cornea > iris > lens > ganglion cell layer > retina

Question 26

The middle ear converts

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

Question 27

Which of the following is not a true description of the transduction of a stimulus by sensory receptors into signals in the form of action potentials?

A) Light can cause some molecules to change conformation, which then triggers a cascade of events leading to a change in the cell's membrane.
B) Molecules in the air travel up the nose to the mucous membranes, where they bend cilia in hair cells, open ion channels, and cause depolarization of the cell membrane.
C) Pressure from sound waves bends cilia in specialized hearing cells, causing ion channels in the plasma membrane to open or close and resulting in a change in ion flow that depolarizes or hyperpolarizes the membrane.
D) Many types of molecules can bind to a variety of receptors in taste cells, leading to depolarization of the cell membrane and causing the taste sensation of bitterness.
E) Na⁺ and H⁺ can flow through sodium and proton channels respectively to directly depolarize the cell membranes of some taste cells, causing the salty or sour taste sensations.

Question 28

Sound waves arriving at a listener first strike the membrane.

A) basilar
B) round- window
C) tectorial
D) hair cell
E) tympanic

Question 29

Mammals have a family of 500 and 1000 genes that encode receptor proteins on the surface of odour- receptor neurons. If all mammals have these genes, why do some mammals have a better sense of smell than others do?

A) Some species of mammals have a larger set of "basic odors" than other species.
B) Some of the genes may have been mutated and rendered inactive in some species but not in others.
C) Some species, particularly humans, rely much less on odor detection for survival; thus, the genes have mutated to encode proteins that aid in other senses, such as sight.
D) Some of the genes actively transcribing receptor proteins in some species are completely absent in other species.

Question 30

How do citrus fruits such as lemons cause the basic taste of sour?

A) The vitamin C of citrus fruits binds to specialized receptors on the plasma membrane of taste cells that trigger a sour taste response.
B) Sugars and vitamin C molecules bind simultaneously to receptors on the taste cells, creating a mix of bitter and sweet that results in the sour taste.
C) Citrus fruits release protons from citric acid) that flow directly into taste cells through H⁺ channels in the plasma membrane.
D) Citric acid amplifies the sour taste of vitamin C when it binds to specialized receptors on the taste cells.

Question 31

Damage to sensory receptor cells would most likely result in
I. confusion of visual and auditory input.
II. inaccurate integration of sensory information.
III. an inability to detect sensory information.

A) only II and III
B) I, II, and III
C) only III
D) only II
E) only I

Question 32

During light detection in a photoreceptor, light directly causes what molecular change?

A) a retinal change from cis to trans conformation
B) breakdown of ATP to ADP
C) increase in cGMP levels
D) inactivation of phosphodiesterase
E) increase in Na⁺ entry into the photoreceptor

Question 33

Compared to human eyes, the eyes of cephalopods squid and octopus)

A) are not camera eyes and do not have a single lens.
B) are inferior because they have few photoreceptors.
C) are extremely similar, with no significant differences.
D) have an adaptive advantage because they do not have a blind spot.

Question 34

Two students studying physiology taste a known "bitter" substance, and both report sensing bitterness. They then sample another substance. Student A reports sensing both a bitter taste and a salty taste, but student B reports only a salty taste. What is the most logical explanation?

A) Student A has normal saliva, whereas student B's saliva is more alkaline than normal.
B) Student A had an allergic reaction to the food, causing him to perceive the food as being bitter.
C) Student A has a protein receptor capable of detecting a bitter molecule found in that substance, whereas student B lacks that particular protein receptor.
D) Student A has normal "bitter" taste buds; student B has defective "bitter" taste buds that result in lower sensitivity to bitterness.

Question 35

It can be very difficult to select an angle for sneaking up to a grasshopper to catch it because grasshoppers have

A) a camera- like eye with multiple fovea.
B) eyes with multiple fovea.
C) excellent hearing for detecting predators.
D) binocular vision.
E) compound eyes with multiple ommatidia.

Question 36

Which sequence of events below best describes how sensory receptors within the lateral line of many fish provide information about stimulus intensity to the brain?

A) Hyperpolarization leads to a large change in membrane potential, inducing a low frequency of action potentials.
B) Hyperpolarization leads to a small change in membrane potential, inducing a high frequency of action potentials.
C) Depolarization leads to a large change in membrane potential, inducing a high frequency of action potentials.
D) Depolarization leads to a small change in membrane potential, inducing a high frequency of action potentials.

Question 37

Mechanoreceptors that react to changes in pressure are part of the

A) human sense of smell.
B) lateral line systems in fish.
C) human sense of taste.
D) pain receptors in birds.
E) eyes in arthropods.

Question 38

What would happen if an enzyme inhibitor for the enzyme phosphodiesterase PDE) was applied to a vertebrate eye?

A) The opsins found in cones would not be differentiated into the red, blue, and green proteins, causing the animals to be colour blind.
B) The lens could not be appropriately adjusted to focus light on the retina, resulting in either nearsightedness or farsightedness.
C) The cGMP- gated sodium channels would remain open, glutamate would be continuously discharged at the synapses, and the brain would not detect light absorbed by the rod cells.
D) All of the listed responses are correct.

Question 39

Which of the sequence of events below best describes how hair cells sterocilia) in the rabbit ear provide the brain with information about stimulus intensity?

A) Soft wind bends the hair, Na⁺ channels open leading to depolarization, low concentration of neurotransmitter released and low frequency of action potentials in afferent neuron to the brain.
B) Strong wind bends the hair, K⁺ channels open leading to depolarization, high concentration of neurotransmitter released and high frequency of action potentials within the afferent neuron to the brain.
C) Strong wind bends the hair, Na⁺ channels open leading to hyperpolarization, high concentration of neurotransmitter released and high frequency of action potentials in afferent neuron to the brain.
D) Soft wind bends the hair, K⁺ channels open leading to hyperpolarization of the membrane, low concentration of neurotransmitter released and low frequency of action potentials within the afferent neuron to the brain.

Question 40

You have a baby that does not seem to respond to sound. Upon thorough investigation by the doctor, there is nothing visibly wrong with the baby's ears. What internal issue may there be that is causing hearing impairment in your baby?

A) The stereocilia within the cochlea are malformed, causing them not to bend properly in response to vibrations of the cochlear membranes caused by different sound frequencies.
B) The auditory ossicles within the inner ear are not transmitting the sound waves properly because the first and second ossicles broke apart.
C) The stereocilia within the middle ear are malformed so sound is not transmitted from the outer ear to the inner ear.

Question 41

Odourant molecules activate sensory neurons by

A) binding to membrane- bound receptor proteins of sensory neurons.
B) deflecting the cilia of hairs cells, leading to the release of neurotransmitter.
C) altering basilar membrane stiffness to shift response by receptor cells.
D) binding to rhodopsin, leading to a change in cGMP levels.
E) passing through ion channels and altering membrane potentials.

Question 42

What do sharks use the ampullae of Lorenzini for?

A) mechanoreception
B) magnetoreception
C) electroreception
D) photoreception
E) thermoreception

Question 43

Vertebrates and cephalopods have eyes that are structurally very similar. One key difference is that cephalopods do not have a blind spot. What causes the blind spot in vertebrates?

A) The eye has 2 lens, so there is an area where the lenses converge where focus is lost and the picture vanishes.
B) An area of the retina does not have photoreceptors on it.
C) Axons of the ganglion cells exiting the eye through the optic nerve block some of the photoreceptor cells on the inner surface of the retina.
D) Both A and B are reasons why vertebrates have a blind spot.
E) Both B and C are reasons why vertebrates have a blind spot.