Question

Fiona puts her hands into a sinkful of lukewarm water; Luke puts his hands into a sinkful of ice-cold water. What should we predict about their action potentials?

a) Fiona's will be weaker because the stimulus is less intense.
b) Their action potentials will be the same due to the all-or-none principle.
c) Luke's will travel a shorter distance because the stimulus is more intense.
d) Luke's will travel faster because the stimulus is more intense.

Answer 1

Fiona's and Luke's action potentials would be the same in strength due to the all-or-none principle, even though the stimuli of lukewarm and ice-cold water differ in intensity. The all-or-none principle ensures action potentials are uniform in magnitude once the threshold is met, although stimulus intensity can affect the frequency of action potentials, not their strength or speed.

Step-by-step explanation:

The correct prediction about their action potentials is that Fiona's and Luke's action potentials will be the same:

Because to the all-or-none principle. The intensity of the stimulus can lead to a greater frequency of action potentials, thus potentially influencing the perception of temperature or the sensation of pain, but individual action potentials remain uniform in size.

Furthermore, it's important to note that while action potentials are uniform, the speed at which they travel can be affected by factors such as temperature, as cooler temperatures can slow down nerve conduction. However, the question's phrasing leads to the conclusion that the all-or-none principle is the primary concept being tested, and thus the intensity of the stimulus (lukewarm vs. cold) would not alter the intrinsic properties of an individual action potential.