Final answer:
A single motor neuron controlling over 900 muscle cells suggests that the muscle is designed for powerful contractions rather than fine movements, which is characteristic of muscles like the quadriceps. These muscles are controlled by motor neurons that originate in the spinal cord and connect via axons to muscle fibers, forming motor units that regulate contraction strength through recruitment.
Step-by-step explanation:
Based on electrophysiology experiments establishing that a single motor neuron controls more than 900 muscle cells, it is likely that the muscle in question is located in an area of the body requiring powerful contractions rather than precise, fine movements. Muscles such as the quadriceps are known to have many fibers controlled by a single motor neuron for this reason. These large, powerful muscles do not require the same level of precision as muscles in areas like the eyes, where the extraocular muscles are controlled by motor neurons that each innervate only a small number of fibers for very precise movements.
The presence of a single motor neuron controlling a large amount of muscle fibers implies that the muscle functions where high force is necessary. Thus, a muscle like the quadriceps fits this description as it is involved in powerful actions like jumping, running, and squatting. The motor neurons originate in the spinal cord and project their axons through spinal nerves to the muscle fibers at the neuromuscular junctions, forming part of the body's sophisticated network of motor units.