Which plant is used for demonstrating plasmolysis in the laboratory?

The process of selective transmission through a semipermeable membrane is called:

If we apply pressure from the top on the solution in the stem of a thistle funnel, we can prevent the entry of water through osmosis. The pressure at which the entry of water through a semi-permeable membrane is stopped is called ........

What occupies the space between the cell wall and the shrunken protoplast in the plasmolysed cell?

Read the given statements regarding the different stages of plasmolysis and choose the correct option.
$I.$ First stage of plasmolysis,when osmotic concentration of cell sap is just equivalent to that of external solution.
$II.$ Protoplast withdraws itself from the corners of the cell wall.
$III.$ Protoplast gets detached from the cell wall and attains a spherical shape.

When pieces of potato tissue were placed in a solution,after some time a loss in weight was recorded. The possible reason could be