Two similar animal cells are placed in two different solutions:
• Cell X is placed in pure water.
• Cell Y is placed in a concentrated salt solution.
Cells are observed after some time. Cell X swells, and cell Y shrinks.
Which statement provides the correct explanation for the above observations?
(a) Salt molecules moved into cell Y, causing it to shrink.
(b) Water moved into cell X and more water moved out of cell Y than the salt solution entered in it.
(c) Water moved into cell X and moved out of cell Y through the cell membrane.
(d) Solute movement caused osmosis in both cells.
(c) Water moved into cell X and moved out of cell Y through the cell membrane.
Explanation: The cell membrane is selectively permeable and allows the movement of water molecules through osmosis.
Cell X is placed in pure water, which is hypotonic compared to the cell contents, so water enters the cell and causes it to swell. Cell Y is placed in a concentrated salt solution, which is hypertonic, so water moves out of the cell, causing it to shrink. Thus, the observations are explained by the osmosis across the cell membrane.
