Final answer:
Resting membrane potential is the voltage difference across a cell membrane in a steady state, typically between -50 to -70 mV, indicating a negative charge inside the cell relative to the outside.
Step-by-step explanation:
Resting membrane potential is the difference in voltage across a cell's membrane when the cell is not actively sending signals. It does not mean the voltage difference is equal to zero. In fact, the resting membrane potential is typically between -50 millivolts (mV) to -70 mV for most animal cells. The negative value signifies that the inside of the cell is negatively charged relative to the outside; this is due to a higher concentration of positive ions (mainly potassium ions) outside the cell and an excess of negative charges inside the cell. Ion pumps and ion channels play crucial roles in maintaining this potential by moving ions in and out of the cell, thus establishing a charge difference across the membrane.