Chapter 44 – Sensory Systems
44–61
Clarify Question
What is the key concept addressed by the question?
• Similarities between the ear and the lateral line.
What type of thinking is required?
Gather Content
What do you already know about the lateral line and inner ear? What other information is
related to the question?
Choose Answer
Given what you now know, what information is most likely to produce the correct answer?
Reflect on Process
Did your problem-solving process lead you to the correct answer? If not, where did the
process break down or lead you astray? How can you revise your approach to produce a
more desirable result?
Multiple Choice Questions
Hair cells are delicate sensors of sound, movement, and gravity. They
are stimulated by movement of the stereocilia — which are actually microvilli —
and the single kinocilium, which is a true cilium.
Chapter 44 – Sensory Systems
44–62
87. One patient at your audiology clinic has an actin defect, and another patient has a
microtubule defect. How might these defects affect the function of their hair cells in hearing?
Clarify Question
What is the key concept addressed by the question?
What type of thinking is required?
Gather Content
What do you already know about hair cells? What other information is related to the
question?
Choose Answer
Given what you now know, what information is most likely to produce the correct answer?
Reflect on Process
Did your problem-solving process lead you to the correct answer? If not, where did the
process break down or lead you astray? How can you revise your approach to produce a
more desirable result?
Chapter 44 – Sensory Systems
88. One patient at your audiology clinic has an actin defect, and another patient has a
microtubule defect. What sense other than hearing may be affected in these patients?
Chapter 44 – Sensory Systems
44–64
Clarify Question
What is the key concept addressed by the question?
What type of thinking is required?
Gather Content
What do you already know about hair cells? What other information is related to the
question?
Choose Answer
Given what you now know, what information is most likely to produce the correct answer?
Reflect on Process
Did your problem-solving process lead you to the correct answer? If not, where did the
process break down or lead you astray? How can you revise your approach to produce a
more desirable result?
Chapter 44 – Sensory Systems
89. Mutations in the DFNA20/26 locus, which codes for the actin gamma 1 protein, are
associated with congenital deafness. An irate senator complains that government money is
being wasted on studies of this mutant gene — in yeast! “I am no biologist,” says the senator,
“but I am pretty sure yeast don’t have ears.” How do you respond?
Chapter 44 – Sensory Systems
44–66
Clarify Question
What is the key concept addressed by the question?
What type of thinking is required?
Gather Content
What do you already know about mutant genes? What other information is related to the
question?
Choose Answer
Given what you now know, what information is most likely to produce the correct answer?
Reflect on Process
Did your problem-solving process lead you to the correct answer? If not, where did the
process break down or lead you astray? How can you revise your approach to produce a
more desirable result?
Chapter 44 – Sensory Systems
44–67
90. As CO2 builds up in the atmosphere it also accumulates in the oceans, causing
acidification. This poses a challenge to marine creatures that rely on calcium carbonate
deposition such as corals, mollusks, and even fish, which use it to form otoliths. Researchers
investigated whether otolith deposition was impaired at low pH, and were surprised to find
that otoliths were actually larger in this condition. This means that, while coping with global
climate change, at least fish will still be able to maintain which sense(s)?
Chapter 44 – Sensory Systems
Clarify Question
What is the key concept addressed by the question?
What type of thinking is required?
Gather Content
What do you already know about otoliths? What other information is related to the
question?
Choose Answer
Given what you now know, what information is most likely to produce the correct answer?
Reflect on Process
Did your problem-solving process lead you to the correct answer? If not, where did the
process break down or lead you astray? How can you revise your approach to produce a
more desirable result?
Chapter 44 – Sensory Systems
91. What are the categories of taste sensation?
92. You make a knockout of a gene involved in neurological
development, and find that the mice have malformed semicircular
canals. Instead of being orthogonal (at right angles) to each other, they
are parallel. What aberrant behavior might you see in these mice?
Chapter 44 – Sensory Systems
Clarify Question
What is the key concept addressed by the question?
What type of thinking is required?
Gather Content
What do you already know about semicircular canals? What other information is related to
the question?
Choose Answer
Given what you now know, what information is most likely to produce the correct answer?
Reflect on Process
Did your problem-solving process lead you to the correct answer? If not, where did the
process break down or lead you astray? How can you revise your approach to produce a
more desirable result?
Chapter 44 – Sensory Systems
44–71
93. In 1908, chemist Kikunae Ikeda identified a new taste modality he called “umami”, or
“delicious” in Japanese. It gives a savory flavor to meat, seaweed, and tomatoes. What
molecule is responsible for umami?
94. Beta-N-Methylamino-L-Alanine, or BMAA, is a glutamate receptor agonist produced by
cyanobacteria. Since Glu is an excitatory neurotransmitter, it is not surprising that BMAA is
associated with neurological damage. Buildup of BMAA in fruit bats was hypothesized to
cause neurodegenerative disease in islanders that fed on the bats. A recent study found high
levels of BMAA in sharks, suggesting that consumption of shark fin soup is also dangerous.
The researchers suggested that a secondary effect of BMAA may actually make these
hazardous foods surprisingly desirable. What might this be?
Chapter 44 – Sensory Systems
44–72
Clarify Question
What is the key concept addressed by the question?
What type of thinking is required?
Gather Content
What do you already know about glutamate? What other information is related to the
question?
Choose Answer
Given what you now know, what information is most likely to produce the correct answer?
Reflect on Process
Did your problem-solving process lead you to the correct answer? If not, where did the
process break down or lead you astray? How can you revise your approach to produce a
more desirable result?
Chapter 44 – Sensory Systems
44–73
95. The bitter receptor hTAS2R38 is activated by glucosinolates found in plants such as
turnips and broccoli. The gene variant a person has determines how sensitive their neurons are
to these compounds. What would you predict for people who have the high-sensitivity variant
of hTAS2R38?
Chapter 44 – Sensory Systems
Clarify Question
What is the key concept addressed by the question?
What type of thinking is required?
Gather Content
What do you already know about taste receptors? What other information is related to the
question?
Choose Answer
Given what you now know, what information is most likely to produce the correct answer?
Reflect on Process
Did your problem-solving process lead you to the correct answer? If not, where did the
process break down or lead you astray? How can you revise your approach to produce a
more desirable result?
Chapter 44 – Sensory Systems
44–75
96. The bitter receptor hTAS2R38 is activated by glucosinolates found in plants such as
turnips and broccoli. Glucosinolates can block synthesis and transport of iodine. Before the
advent of iodized salt, this was a particular problem in areas of the world that are naturally
low in iodine. Why might the human population include different variants of the hTAS2R38
gene?
Chapter 44 – Sensory Systems
44–76
Clarify Question
What is the key concept addressed by the question?
What type of thinking is required?
Gather Content
What do you already know about taste receptors? What other information is related to the
question?
Choose Answer
Given what you now know, what information is most likely to produce the correct answer?
Reflect on Process
Did your problem-solving process lead you to the correct answer? If not, where did the
process break down or lead you astray? How can you revise your approach to produce a
more desirable result?
Chapter 44 – Sensory Systems
97. Which sensory modality responds to the broadest range of molecules?
Chapter 44 – Sensory Systems
Clarify Question
What is the key concept addressed by the question?
• What sensory modality responds to the most molecules?
What type of thinking is required?
Gather Content
What do you already know about sensory modalities? What other information is related to
the question?
Choose Answer
Given what you now know, what information is most likely to produce the correct answer?
Reflect on Process
Did your problem-solving process lead you to the correct answer? If not, where did the
process break down or lead you astray? How can you revise your approach to produce a
more desirable result?