Based on the idea in Weber's Law in which the just-noticeable difference in a stimulus is proportional to the magnitude of the stimulus, what is an advantage of having motor units of different sizes recruited in an orderly manner? If there were a small weight, for example, then small motor units would be recruited.

In the experiment illustrated in Figure Q8-1, five fluorescently labeled actin filaments on a myosin-coated glass slide were tracked over the course of 38 s, and their positions were tracked at successive short intervals as they appeared on a video monitor. Figure Q8-1
If you could make an ATP molecule that could not be hydrolyzed to ADP and performed the same experiment, what would happen to the fluorescent actin and why?

What is the function of the pacemaker neuron in a central pattern generator?