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. experimental setup and results which statement provides a conclusion about the transport of water in and out of cells based on the results of the students experiment? (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 and solutes move out of the cell to ensure their concentration is balanced both inside and outside the cell.

Explanation:

• Option A: Incorrect. The experiment shows that water movement is affected by solute concentration. For example, in the 3% sucrose solution (higher solute concentration outside the bag compared to 1% inside), water moves out (bag shrinks), while in distilled water (lower solute concentration outside), water moves in (bag swells).
• Option B: Correct. Osmosis (water movement) is based on the concentration gradient of solutes. When the solute concentration outside is lower (distilled water, effectively 0% sucrose), water moves in (bag swells). When it's higher (3% sucrose), water moves out (bag shrinks). When equal (1% inside and outside), there is no net water movement (bag shape remains similar).
• Option C: Incorrect. The experiment focuses on water movement (osmosis), not water transporting solutes out of the cell. The plastic bags (representing cells) are semi - permeable, and the movement is mainly of water based on concentration gradients.
• Option D: Incorrect. The experiment does not show solutes moving out of the cell. The plastic bags are semi - permeable, and the main movement observed is of water (osmosis) based on the solute concentration difference.

Answer:

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