Final answer:
Activation of intrafusal fibers by alpha motoneurons creates muscle tone.
Step-by-step explanation:
Muscle tone is accomplished by the activation of a few motor units at a time, which is controlled by the nervous system. Intrafusal fibers, which are specialized muscle fibers found in muscle spindles, also play a role in muscle tone. These fibers are activated by alpha motoneurons and help maintain the length and sensitivity of the muscle spindle, which in turn contributes to muscle tone.