What does the dashed line in the beaker separating the two sides

I guess the correct answer is A membrane

A mеmbranе is a sеlеctivе barriеr; it allοws sοmе things tο pass thrοugh but stοps οthеrs. Such things may bе mοlеculеs, iοns, οr οthеr small particlеs.

What does the dashed line in the beaker separating the two sides represent membrane potential?

Explanation:

Membrane Potential:

A gradient is membrane, through which the different molecules move from one portions of the body or system into the another. It is due to the potential difference between the two sides, as there are different factors which involves in the movement from point of a system into another.

As, the diffusion occurs through the difference in potential between the sides, along with that it can also lead to the process of osmosis. As osmosis is the movement of the particles across any membrane through a small aperture present in the membrane.