Final answer:
The correct answer to the student's question is that a channel that opens in response to changes in ionic charge across a membrane is called a voltage-gated channel. The correct option is 1) voltage-gated channel
Step-by-step explanation:
A channel that opens in response to changes in ionic charge across a membrane is called a voltage-gated channel. These channels are sensitive to alterations in the electrical properties of the cell membrane.
Typically, when the internal voltage of a membrane becomes less negative, the voltage-gated channel opens, allowing ions to move across the membrane.
This process is crucial for the function of cells involved in electrical impulses, like neurons and muscle cells. An example of this is the voltage-gated sodium (Na+) channel, which opens in response to a change in membrane voltage and plays a significant role in the transmission of neural signals. The correct option is 1) voltage-gated channel