1. Which of these is NOT a method by which sensory receptors receive information about the internal or external environment?
a. Changes in pressure
b. Light or heat changes
c. Changes in molecular concentration
d. All of these are used by sensory receptors
The correct answer is d—
A. Answer a is incorrect.All of these answers are mechanisms of sensory reception.
The correct answer is d—
B. Answer b is incorrect.All of these answers are mechanisms of sensory reception.
The correct answer is d—
C. Answer c is incorrect.All of these answers are mechanisms of sensory reception.
The correct answer is d—All of these are used by sensory receptors
D. Answer d is correct.All of these answers are mechanisms of sensory reception.
2. Which of the following correctly lists the steps of perception?
a. Interpretation, stimulation, transduction, transmission
b. Stimulation, transduction, transmission, interpretation
c. Interpretation, transduction, stimulation, transmission
d. Transduction, interpretation, stimulation, transmission
The correct answer is b—
A. Answer a is incorrect.The proper sequence of events ends with interpretation and begins with stimulation.
The correct answer is b—Stimulation, transduction, transmission, interpretation
B. Answer b is correct. The proper order is stimulation, transduction, transmission, interpretation.
The correct answer is b—
C. Answer c is incorrect.Interpretation is the last step in the sequence.
The correct answer is b—
D. Answer d is incorrect.The proper sequence of events begins with stimulation and is followed by transduction.
3. Your Aunt Hattie stood up suddenly at Sunday dinner and then fainted. The doctor said that it might be a problem involving her baroreceptors. What is the function of baroreceptors?
a.They detect changes in blood pressure.
b.They detect muscle contractions and the movement of limbs.
c.They are exteroceptors.
d.They detect changes in blood chemistry.
The correct answer is a—They detect changes in blood pressure.
A. Answer a is correct. Baroreceptors measure changes in pressure within the circulatory system and allow the body to compensate.
The correct answer is a—
B. Answer b is incorrect.The receptors that measure muscle contraction are proprioreceptors.
The correct answer is a—
C. Answer c is incorrect.Exteroceptors measure changes outside of the body, which is not the function of baroreceptors.
The correct answer is a—
D. Answer d is incorrect.The receptors that measure chemical changes are chemoreceptors.
4. All sensory receptors are able to initiate nerve impulses by opening or closing—
a.voltage-gated ion channels
b.exteroceptors
c.interoceptors
d.stimulus-gated ion channels
The correct answer is d—
A. Answer a is incorrect.Sensory stimuli may or may not involve changes in voltage so this is not a complete answer.
The correct answer is d—
B. Answer b is incorrect. Exteroceptors are another term for a type of receptor. They are not structures within receptors.
The correct answer is d—
C. Answer c is incorrect.Interoceptors are another term for a type of receptor. They are not structures within receptors.
The correct answer is d—stimulus-gated ion channels
D. Answer d is correct. Unlike other neurons, sensory neurons can be stimulated by a variety of stimuli as long as a given stimulus is capable of opening the gated ion channels.
5. In the fairytale, Sleeping Beauty fell asleep after pricking her finger. What kind of receptor responds to that kind of painful stimulus?
a.Mechanoreceptor
b.Nociceptor
c.Thermoreceptor
d.Touch receptor
The correct answer is b—
A. Answer a is incorrect.Mechanoreceptors would respond to pressure or physical deformation.
The correct answer is b—Nociceptor
B. Answer b is correct. Nociceptors are stimulated by pain.
The correct answer is b—
C. Answer c is incorrect.Only nociceptors are stimulated by pain.
The correct answer is b—
D. Answer d is incorrect.Only nociceptors are stimulated by pain.
6. The ear detects sound by the movement of—
a.the basilar membrane
b.the tectorial membrane
c.the Eustachian tube
d.fluid in the semicircular canals
The correct answer is a—the basilar membrane
A. Answer a is correct. The basilar membrane vibrates in response to sound waves and allows the ear to detect sound.
The correct answer is a—
B. Answer b is incorrect.The tectorial membrane does not directly respond to sound waves.
The correct answer is a—
C. Answer c is incorrect.The Eustachian tube is not a structure used to detect sound.
The correct answer is a—
D. Answer d is incorrect.The fluid in the semicircular canals does not detect sound.
7. A friend who knows that you are afraid of snakes told you that you should wrap yourself in insulation when you go into the woods so that the snakes won’t be able to find you. You now realize, after reading the chapter, that she was right (sort of) because snakes use their ______for detecting infrared radiation as heat.
a.photoreceptors
b.cochlea
c.semicircular canals
d.pit organs
The correct answer is d—
A. Answer a is incorrect.The photoreceptors do not detect heat.
The correct answer is d—
B. Answer b is incorrect.Cochlea is not used to detect heat.
The correct answer is d—
C. Answer c is incorrect.The semicircular canals contain the structures that allow the body to sense movement and direction.
The correct answer is d—pit organs
D. Answer d is correct.Pit organs are used by snakes to detect heat.
8. Hair cells in the vestibular apparatus of terrestrial vertebrates—
a. measure temperature changes within the body
b. sense sound in very low range of hearing
c. provide a sense of acceleration and balance
d. measure changes in blood pressure
The correct answer is c—
A. Answer a is incorrect.Temperature is measured by thermoreceptors.
The correct answer is c—
B. Answer b is incorrect.Sound is detected by hair cells in the basilar membrane of the cochlear duct.
The correct answer is c—provide a sense of acceleration and balance
C. Answer c is correct.The proper sequence of events during an action potential begins with the rising phase, followed by the falling phase, and finally the undershoot.
The correct answer is c—
D. Answer d is incorrect.The proper sequence of events during an action potential begins with the rising phase, followed by the falling phase, and finally the undershoot.
9. Think back to the meal you ate for lunch. The ability to taste food relies on—
a. external chemoreceptors
b. internal chemoreceptors
c. olfactory receptors
d. nociceptors
The correct answer is a—external chemoreceptors
A. Answer a is correct. The taste buds (chemoreceptors) measure changes on the outside of the body itself.
The correct answer is a—
B. Answer b is incorrect.Internal chemoreceptors measure changes within the tissues and bloodstream.
The correct answer is a—
C. Answer c is incorrect.Olfactory receptors sense smell, not taste.
The correct answer is a—
D. Answer d is incorrect. Nociceptors respond to pain, not taste.
10. What do the sensory systems of annelids, mollusks, arthropods, and chordates have in common?
a. They all use the same stimuli for taste.
b. They all use neurons to detect vibration.
c. They all have image-forming eyes that evolved independently.
d. They all use chemoreceptors in their skin to detect food.
The correct answer is c—
A. Answer a is incorrect.These organisms live in diverse habitats and are exposed to diverse chemical “tastes.”
The correct answer is c—
B. Answer b is incorrect.Neurons are not used for vibration detection.
The correct answer is c—They all have image-forming eyes that evolved independently.
C. Answer c is correct.All of these organisms have image-forming eyes which apparently evolved independently.
The correct answer is c—
D. Answer d is incorrect.Not all of the organisms have “skin,” nor do they use chemoreceptors there to find food.
11. While honeymooning in Borneo you find a previously unidentified species of mammal. You proceed to explain to your very patient spouse that the placement of the eyes on the same side of the head (face) such that the visual fields overlap—
a. is found in primates and predators
b. is called binocular vision
c. allows for depth perception
d. all of the above
The correct answer is d—
A. Answer a is incorrect.There is more than one correct answer to this question.
The correct answer is d—
B. Answer b is incorrect.There is more than one correct answer to this question.
The correct answer is d—
C. Answer c is incorrect.There is more than one correct answer to this question.
The correct answer is d—all of the above
D. Answer d is the correct answer.All of these are correct. But maybe you shouldn’t spend too much time explaining this, it is your honeymoon!
12. You arise to a beautiful day. As you raise your eyelids and catch your first glimpse of the brand new day, the structure that actually admits light into your eye is the—
a. retina
b. fovea
c. pupil
d. lens
The correct answer is c—
A. Answer a is incorrect.The retina is not the first structure to receive light in the eye.
The correct answer is c—
B. Answer b is incorrect.The fovea is not the first structure to receive light in the eye.
The correct answer is c—pupil
C. Answer c is correct.The pupil allows light to enter the eye.
The correct answer is c—
D. Answer d is incorrect.The lens is not the first structure to receive light in the eye.
13. ______is the photopigment contained within both rods and cones of the eye.
a. Carotene
b. Cis-Retinal
c. Photochrome
d. Chlorophyll
The correct answer is b—
A. Answer a is incorrect.Although carotene is a pigment, it is not a photopigment found in rods and cones.
The correct answer is b—Cis-Retinal
B. Answer b is correct.Cis-Retinal is a photopigment found in both rods and cones.
The correct answer is b—
C. Answer c is incorrect.Photochrome is not a photopigment found in both rods and cones.
The correct answer is b—
D. Answer d is incorrect.Chlorophyll is not a photopigment found in the rods and cones.
14. Which of the following is NOT a method used by vertebrates to gather information about their environment?
a. Infrared radiation
b. Magnetic fields
c. Electrical currents
d. All of these are methods used for sensory reception
The correct answer is d—
A. Answer a is incorrect.All of these methods are used by vertebrates to gather information.
The correct answer is d—
B. Answer b is incorrect.All of these methods are used by vertebrates to gather information.
The correct answer is d—
C. Answer c is incorrect.All of these methods are used by vertebrates to gather information.
The correct answer is d—All of these are methods used for sensory reception
D. Answer d is correct. All of these methods are used by vertebrates to gather information.
15. The lobe of the brain that recognizes and interprets visual information is the—
a. occipital lobe
b. frontal lobe
c. parietal lobe
d. temporal lobe
The correct answer is a—occipital lobe
A. Answer a is correct. The occipital lobe of the brain interprets visual signals.
The correct answer is a—
B. Answer b is incorrect.The frontal lobe is not primarily involved in processing visual stimuli.
The correct answer is a—
C. Answer c is incorrect.The parietal lobe is not primarily involved in processing visual stimuli.
The correct answer is a—
D. Answer d is incorrect.The temporal lobe is not primarily involved in processing visual stimuli.
Challenge Questions
1. When blood pH falls too low, a potentially fatal condition known as acidosis results. Among the variety of responses to this condition, the body will change the breathing rate. How does the body sense this change? How does the breathing rate change? How does this increase pH?
Answer—When blood pH becomes acidic, chemoreceptors in the circulatory and the nervous systems notify the brain and the body responds by increasing the breathing rate. This causes an increase in the release of carbon dioxide through the lungs. Decreased carbon dioxide levels in the blood cause a decrease in carbonic acid, which, in turn, causes the pH to rise.
2. The function of the vertebrate eye is unusual compared with other processes found within the body. For example, the direction in which sensory information flows is actually opposite to the path that light takes through the retina. Explain the sequence of events involved in the movement of light and information through the structures of the eye, and explain why they move in opposite directions.
Answer—In order to reach the retina and generate action potentials on the optic nerve, light must first pass through the ganglion and bipolar cells to reach the rods and cones that synapse with the bipolar cells. The bipolar cells then synapse with ganglion cells. These in turn send action potentials to the brain. Because the retina comprises three layers, with the rods and cones located farthest from the pupil, light must travel to the deepest level to set off reactions that move up through the more superficial levels and result in optic signals.
3. How would the otolith organs of an astronaut respond to zero gravity? Would the astronaut still have a subjective impression of motion? Would the semicircular canals detect angular acceleration equally well at zero gravity?
Answer—Without gravity to force the otoliths down toward the hair cells, the otolith organ will not function properly. The otolith membrane would not rest on the hair cells and would not move in response to movement of the body parallel or perpendicular to the pull of gravity. Consequently, the hair cell would not bend and so would not produce receptor potentials. Because the astronauts can see, they would have an impression of motion―they can see themselves move in relation to objects around them―but with their eyes closed, they would not know if they were moving in relation to their surroundings. Because their proprioceptors would still function, they would be able to sense when they moved their arms or legs, but they would not have the sensation of their enter body moving through space.
The semicircular canals would not function equally well in zero-gravity conditions. Although the fluid in the semicircular canals is still able to move around, some sensation of angular movement would most likely occur, but the full function of the semicircular canals requires the force of gravity to aid in the directional movement of the fluid in the canals.