If you look away from this book and focus your eyes on a distant object, the eye muscles _________ and the lenses _________ to focus images on the retinas.
a. Relax . . . Flatten
b. Relax . . . Become more rounded
c. Contract . . . Flatten
d. Contract . . . Become more rounded

Which of the following sensory receptors is incorrectly paired with its category?

a. Hair cell . . . Mechanoreceptor

b. Taste receptor . . . Chemoreceptor

c. Rod . . . Electromagnetic receptor

d. Olfactory receptor . . . Electromagnetic receptor

Which of the following are not known to be present in human skin?

a. Thermoreceptors

b. Electromagnetic receptors

c. Pressure receptors

d. Pain receptors

What do the receptor cells in the lateral line system along the sides of a shark and the cochlea of your ear have in common?

a. They use hair cells to sense sound or pressure waves.

b. They are organs of equilibrium.

c. They use electromagnetic receptors to sense pressure waves in fluid.

d. They use granules that signal a change in position and stimulate their receptor cells.

Eighty-year-old Mr. Johnson was becoming slightly deaf. To test his hearing, his doctor held a vibrating tuning fork tightly against the back of Mr. Johnson's skull. This sent vibrations through the bones of the skull, setting the fluid in the cochlea in motion. Mr. Johnson could hear the tuning fork this way, but not when it was held away from the skull a few inches from his ear. The problem was probably in the _________ . (Explain your answer.)

a. Auditory nerve leading to the brain

b. Hair cells in the cochlea

c. Bones of the middle ear

d. Fluid of the cochlea