Question

what would be the best explanation for why myelinated axons conduct signals faster than unmyelinated axons? multiple choice there are no sodium channels in unmyelinated axons. myelinated axons contain more sodium ions. myelinated axons have more sodium - potassium pumps in their membranes. active transport of sodium and potassium is faster in myelinated axons. electrical signals spread faster through insulated (myelinated) regions of axon.

Explanation:

Myelin is an insulating layer around axons. In myelinated axons, electrical signals (action - potentials) can "jump" from one node of Ranvier (unmyelinated regions) to the next, a process called saltatory conduction. This is much faster than continuous conduction in unmyelinated axons. The other options are incorrect as unmyelinated axons do have sodium channels, and there is no evidence that myelinated axons have more sodium ions, more sodium - potassium pumps, or faster active transport of sodium and potassium.

Answer:

Electrical signals spread faster through insulated (myelinated) regions of axon.