Questions: Part B - Loss of K lons Loss of K ions from the cytosol will have the same effect as: loss of Cl ions gain of K ions gain of Cl ions gain of Na ions

The answer is the first one: loss of Cl ions.

Explanation for each option:

1. Loss of Cl ions: The loss of $K$ ions from the cytosol would lead to a decrease in the positive charge inside the cell. Similarly, the loss of Cl ions, which are negatively charged, would also lead to a decrease in the negative charge inside the cell. Both scenarios result in a change in the ionic balance and membrane potential, making them comparable in effect.

2. Gain of $K$ ions: This is the opposite of the loss of $K$ ions. Gaining $K$ ions would increase the positive charge inside the cell, which is not the same effect as losing $K$ ions.

3. Gain of Cl ions: Gaining Cl ions would increase the negative charge inside the cell, which is the opposite effect of losing $K$ ions.

4. Gain of Na ions: Gaining Na ions would increase the positive charge inside the cell, which is not the same effect as losing $K$ ions.

Summary: The loss of $K$ ions from the cytosol will have the same effect as the loss of Cl ions, as both result in a change in the ionic balance and membrane potential in a similar manner.