Question

(Ch. 8.3; Electrical Signals in Neurons) The spread of a graded potential is different than the propagation of an action potential because the graded potential

has a constant amplitude as it spreads.

can spread without opening any ion channels.

requires voltage-gated sodium channels.

is most effective in axons, whereas action potentials are most effective in dendrites.

creates a relatively long refractory period.

Answer 1

Graded potential are those which arise in response to local stimuli. The amplitude varies, depending on the intensity of stimuli. As it spreads, strength of graded potential decreases. Action potential on the other hand, arise as a result of membrane depolarization and has a specific threshold.

Graded potential can be summed up, but action potential cannot be summed up.

Graded potential is most effective in dendrites, and action potential in axons.

Graded potential has no refractory period unlike action potential.

Graded potential mainly involves ligand gated ion channels, whereas action potential involves voltage gated channels.

Hence, none of the given choices is correct.