Question

A student performs an experiment to study the transport of water in and out of cells. He uses clear, semi-permeable plastic bags to represent the cell membrane. The student places three plastic bags of the same size, each containing a 1% concentration sucrose solution, into three different beakers. One beaker contains distilled water, another beaker contains a 3% concentration sucrose solution, and the third beaker contains a 1% concentratIon sucrose solution. The diagram shows the students experimental setup, the plastic bag before it is placed in the beakers, and the appearance of the bags after an hour in each solution. Which statement provides a conclusion about the transport of water in and out of cells based on the results of the students experiment?

Answer 1

B

Step-by-step explanation:

A. Water moves freely both inside and outside the cell independent of the solute concentration.

B. Water movement into the cell is dependent on the percent concentration of solutes both inside and outside the cell.

C. Water transports solutes out of the cell to balance the percent concentration of solutes both inside and outside the cell.

D. Water moves into the cell solutes move out of the cell to ensure their concentration is balanced both inside and outside the cell.

The correct statement that provides a conclusion about the transport of water in and out of the cells is that water movement into the cell is dependent on the percent concentration of solutes both inside and outside the cell.

Water molecules will always move from the region of higher water potential to the region of lower water potential. The more the solute concentration of a solution, the lower the water potential compared to a solution with a lower solute concentration.

Hence, water will move from the beaker containing distilled water into the plastic bag containing a 1% sucrose solution until an equilibrium is established - the solution in the beaker is hypotonic to the one in the bag.

On the contrary, water will move from the bag containing 1% sucrose solution into the beaker containing 3% sucrose solution until there is no longer any net movement of water - the solution in the beaker is hypertonic to the one in the bag.

There will not be any movement of water from the bag to the beaker containing 1% sucrose because both solutions are of the same concentration, that is, isotonic.

The correct option is B