Question

During osmosis, the semi-permeable membrane is one that: A. allows only very small particles or water through. B. allows only very large particles through. C. does not allow any particles to pass through. D. decides what particles to let through based on cell signals.

Answer 1

Osmosis always moves a solvent in one direction only, from a less concentrated solution to a more concentrated solution. As osmosis proceeds, pressure builds up on the side of the membrane where volume has increased. Ultimately, this pressure prevents more water from entering.

http://www.indiana.edu/~nimsmsf/P215/p215notes/LabManual/Lab5.pdf