5.6.21 - AP Biology - Water Potential

After examining this diagram showing the concentration of water inside and outside of the cell, identify the tonicity of the solution.

• hypertonic

• hypotonic

• isotonic

Nemo and other ocean dwelling fish cannot survive in freshwater because......

• freshwater is hypertonic to Nemo's cells and will result in water leaving them causing the cells to shrink

• freshwater is hypotonic to Nemo's cells and will result in water leaving them causing the cells to shrink

• freshwater is hypertonic to Nemo's cells and will result in water entering them causing the cells to swell and burst

• freshwater is hypotonic to Nemo's cells and will result in water enter them causing the cells to swell and burst

Elodea is a freshwater plant. When it is placed in saltwater what will happen to its cells?

• They will become turgid because water is entering the cell, making them firm

• They will become flaccid because water is entering and leaving the cell at equal rates, making them a little soft

• They will be plasmolyzed because water is leaving the cell, making them shrink significantly

The following questions refer to an experiment in which a dialysis-tubing bag is filled with a mixture of 3% starch and 3% glucose and placed in a beaker of distilled water, as shown below. After 3 hours, glucose can be detected in the water outside the dialysis-tubing bag, but starch cannot.

If, instead of the bag, a potato slice were placed in the beaker of distilled water, which of the following would be true of the potato slice?

• It would gain mass.

• It would neither gain nor lose mass.

• It would absorb solutes from the surrounding liquid.

• It would lose water until water potential inside the cells is equal to zero.

If a cells  $\Psi p$ = 3 bars and its  $\Psi s$ = -4.5 bars, what is the resulting  $\Psi$  ?

• -7.5

• 7.5

• -1.5

• 1.5

The cell with is a  $\Psi s$  of -2.0 bars is placed in a beaker of sugar water with $\Psi s$ of -4.0 bars.  In which direction will the net flow of water be?

• Out of the cell

• Into the cell

• Both into and out of the cell

• Neither into nor out of the cell

A plant cell with a $\Psi s$  of -7.5 bars keeps a constant volume when immersed in an open-beaker solution that has a  $\Psi s$  of -4 bars.  What is the cells  $\Psi p$  ?

• -4

• -7.5

• -3.5

• 3.5

What is the $\Psi s$   of a 1.0M sugar solution in an open beaker at 22 $\degree$ C?

• -24.5 bars

• 24.5 bars

• -2.45

• 2.45

At 22 $\degree$ C, zucchini cores are measured and determined to have a sucrose concentration of 0.36M. What is the $\Psi s$   of these cells and in which direction will the net flow of water be?

• 0.64 net flow of water out of the cell

• -0.36 net flow of water into the cell

• 8.17 net flow of water out of the cell

• -8.83 net flow of water into the cell

At 20 $\degree$ C, a cell containing 0.6M glucose is in equilibrium with its surrounding solution containing 0.5M glucose in an open container.  What is the cell's  $\Psi p$  ? 

• 2.4

• 0.1

• -12.2

• -14.6