Who proved the plasmolysis of sieve tubes?

Osmosis is helpful to plants because

$A$ cell is placed in $0.4 \; M$ solution of sugar and no change in volume of cell is found. What is the concentration of the cell sap (in $; M$)?

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 is correct for osmosis?

How is water absorbed by the roots?