Final answer:
Unmyelinated axons lack myelin sheath support, resulting in slower signal transmission compared to myelinated axons which have myelin sheath produced by Schwann cells and oligodendrocytes, enhancing speed and efficiency.
Step-by-step explanation:
Unmyelinated axons are completely lacking any support from myelin. Myelinated axons, in contrast, have an insulating layer called a myelin sheath that enhances the speed and efficiency of electrical signal transmission. Unmyelinated axons do not have this advantage and therefore conduct signals more slowly.
Myelin is produced by special glial cells, with Schwann cells creating the myelin sheath in the peripheral nervous system, and oligodendrocytes performing a similar function in the central nervous system. The presence of myelin around an axon is crucial for fast and efficient signal transmission and helps prevent signal loss. Without this insulation, as in unmyelinated axons, the nerve signals travel slower and are more susceptible to interference.