Final answer:
A muscle twitch is true. It is a response to a single stimulus of adequate strength but does not produce significant muscle activity. A series of action potentials is necessary to produce a muscle contraction.
Step-by-step explanation:
A muscle twitch is true. A muscle twitch is a response to a single stimulus of adequate strength. However, it is important to note that a single muscle twitch does not produce significant muscle activity. A series of action potentials is necessary to produce a muscle contraction that can produce work.
Normal muscle contraction is more sustained and can be modified by input from the nervous system to produce varying amounts of force. This is known as a graded muscle response. Factors such as the frequency of action potentials from a motor neuron and the number of motor neurons transmitting action potentials can affect the tension produced in skeletal muscle.