Movement of Substance Quiz 3

Water molecules move across the partially premeble membrane into the concentrated sugar solution by osmosis. This results in a rise in the level of the sugar solution in the capillary tube and a fall in the water level in the beaker.

The smallest block has the largest surface area to volume ratio. A high surface area to volume ratio increases the rate of diffusion.

Water from the dilute sucrose solution has entered the more concentrated potato cell sap through Osmosis. The number of water molecules in the sucrose solution decreases resulting in a more concentrated sucrose solution.

When a plant cell is immersed in a solution with water potential lower than that inside the cell, water moves out of the vacuole into the solution by Osmosis. The cytoplasm starts to pull away from the cell wall, leaving a perceptible gap between the cell wall and the plasmolysis. The cell in solution Y has become plasmolyzed. Thus water must have moved out of the cell into solution Y which is of a lower water potential.

Since water is conducted up the xylem, cells nearest to the xylem (X) will have the lowest water potential. Water moves down a water potential gradient from the soil into the roots by Osmosis. Magnesium ions (mineral salt) enter the roots from the soil by diffusion.

During Osmosis, water moves from a solution of lower concentration (higher water potential) to a solution of higher concentration through a selectively permeable membrane.

Boiling the potato could destroy the cell membrane. Without a partially permeable membrane, Osmosis cannot occur. An unboiled potato place in distilled water (high water potential) would result in water entering.

Water moved into the potato cells by osmosis. Osmosis is the movoemnt of water molecules from a region of higher concentration of water to a region of lower concentration of water through the selectively permeable membrane of the cells.

Diffusion is movement of solute molecules (reducing sugar molecules) from a region of higher concentration (inside Visking tubing) to a region of lower concentration of the solute molecules (distilled water) until a uniform concentration is obtained. Diffusion can occur across a permeable or semi permeable membrane.

In order for water to move into the body cells down a water potential gradient by Osmosis, the concentration of tissue fluid must be low (i.e. high water potential) and the concentration of cytoplasm in the body cell must be high (i.e. low water potential).