Question

Samantha and Gregg are learning about the senses and find the following information on the Internet.



Source 1

Inside the inner ear there are structures called otolith organs that detect motions of the head. The otolith organs provide information about changes in head position. The organs have a patch of cells called the macula. The macula is made of several different types of cells, including hair cells that are held in place by supporting cells. The hair cells contain sections that float in a surrounding gel-like fluid called the otolithic membrane. Small crystals (otoconia) lie on top of the membrane. When a person moves her head, the otoconia move, sending sensory information to the brain. The drawing shown below models this action.



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Source 2

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Which of the following correctly compares how people balance and hear?


Both balance and hearing use the ear, but balance senses movement of the body and hearing senses sounds.


Both balance and hearing sense body movement, but balance uses muscles and hearing uses hair cells.


Both balance and hearing sense waves, but balance uses the arms and hearing uses the ear.


Both balance and hearing use hair cells, but balance senses light waves and hearing senses sound waves.

Answer 1

Correct answer:
Both balance and hearing use the ear, but balance senses movement of the body and hearing senses sounds.

Why: Both systems use hair cells in the inner ear, but the otolith organs (and semicircular canals) detect head movement and position (balance), while the cochlea detects sound waves (hearing). The other choices are incorrect about the organs or the types of stimuli detected.