The lock-and-key theory proposes that _____.
a. specific taste molecules have the power to excite specific receptors on the tongue
b. taste sensation occurs when specific molecules split apart to create a chemical chain reaction on the tongue
c. smell sensation occurs when specific molecules split apart to create a chemical chain reaction in the nose
d. specific odor molecules have the power to excite specific receptors in the nose
Correct answer is option D. specific odor molecules have the power to excite specific receptors in the nose. Explanation: The lock-and-key theory proposes that specific odor molecules have the power to excite specific receptors in the nose.