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?

Question

A.  overeating
B.  falling over
C.  not startling to sudden noise
D.  unable to respond to a call to locate another mouse
E.  low muscle tone

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?
 

Answer 1

B.  falling over

Clarify Question
What is the key concept addressed by the question?
        · What are the results of semicircular canal defects?
What type of thinking is required?
            o This is an evaluate question because you have to weigh and judge the different symptoms and behaviors to match expected outcomes of malformed semicircular canals.

Gather Content
What do you already know about semicircular canals? What other information is related to the question?
        · You already know that semicircular canals are part of the inner ear, linked to the cochlea. While the cochlea allows us to hear, the semicircular canals provide us with a sense of balance. The three fluid-filled tubes that make up the semicircular canals are orthogonal to one another. That is, they are oriented at 90 degrees from each other so that motion in any orientation can be detected. If this system did not work, you would not be able to maintain your balance and would fall over easily.

Choose Answer
Given what you now know, what information is most likely to produce the correct answer?
        · Malformed semicircular canals would lead to problems maintaining balance. Thus a behavior you might see in mice with this defect is that they would fall often. The other behavioral problems are not related to semicircular canals.

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?
        o Answering this question correctly depended upon your ability to weigh or judge the validity of certain symptoms of malformed semicircular canals. If you answered incorrectly, which answer did you choose? Did you forget that semicircular canals are involved in maintaining balance?