Question

A neuron's axon:

a. can either by myelinated or unmyelinated
b. usually ends in one "bulb," which physically connects to the next neuron
c. is usually completely covered in myelin from end-to-end
d. nearly always less than two millimeters in length

Answer 1

A neuron's axon can be either myelinated or unmyelinated, usually ends with multiple synaptic end bulbs, and its length can vary greatly, sometimes reaching up to a meter long.

Step-by-step explanation:

A neuron's axon can be either myelinated or unmyelinated. Myelin sheaths act as insulation, increasing the speed of electrical signal conduction. These sheaths are interrupted by gaps known as the nodes of Ranvier, which are essential for the rapid conduction of nerve impulses. An axon typically ends in the axon terminal with multiple branches, each ending in a synaptic end bulb. These bulbs connect with the target cell at the synapse, but do not physically connect to the next neuron. Axons can vary greatly in length, and are not always less than two millimeters. In fact, the axon of a human motor neuron can be up to a meter long, extending from the base of the spine to the toes. Therefore, the most accurate statement is that an axon:

1. can either be myelinated or unmyelinated,
2. usually ends in multiple synaptic end bulbs, and
3. can vary greatly in length.