Prior Knowledge question! An apple, onion, and potato all taste the same when you plug your nose! Why is this so?

because a lot of taste is based off smell

Explanation:

If this channel is blocked, such as when your nose is stuffed up by a cold or flu, odors can't reach sensory cells in the nose that are stimulated by smells. As a result, you lose much of our enjoyment of flavor. Without smell, foods tend to taste bland and have little or no flavor.