Final answer:
An action potential provides information on electrical activity at the single-cell level, involving a rapid voltage change due to ion movement across the neuron or muscle cell membrane.
Step-by-step explanation:
An action potential provides information on the nature of electrical activity at the single-cell level. During an action potential, a neuron or muscle cell undergoes a rapid change in electrical potential difference across its cell membrane.
This process starts when neurotransmitters released at a synapse bind to receptors on the responding neuron or muscle cell, leading to membrane depolarization. Consequently, sodium ions flow into the cell and potassium ions flow out, altering the voltage of the cell's membrane. This change in voltage is what transmits the electrical signal within the neuron or muscle fiber, allowing for communication between cells.
The action potential is critical for the functioning of neurons and muscle cells, serving as a fundamental element in the processing and transmission of information throughout the nervous system and other excitable cells.