AccelePrep for the ACT Test 2nd Edition Student Text

292 • P OWER U P ! T HE E XCLUSIVE C AMBRIDGE S AMPLE E XAM 15. In Experiment 1, osmosis proceeds due to the cell wall permitting: A. sugar molecules but not water molecules to pass. B. water molecules but not sugar molecules to pass. C. neither sugar nor water molecules to pass. D. certain water and certain sugar molecules to pass. 16. The purpose of Experiment 1 is to measure the: F. solute concentrations of the solutions in which the onion strips are submerged. G. quantity of water gained or lost by the onion cells due to osmosis. H. number of cells plasmolyzed due to the effect of osmosis. J. solute concentration threshold at which osmosis is triggered in onion cells submerged in a sugar solution. 17. Which of the following best explains why the students analyze 40 to 65 cells from each onion •–”‹’ ‹ š’‡”‹‡– ͳǫ A. The number of plasmolyzed cells in an onion strip ranges from 40 to 65 cells. B. A sampling adequate to determine the effect of osmosis on onion cells requires 40 to 65 cells. C. The average number of cells in an onion strip is 40 to 65 cells. D. The unanalyzed cells of the onion strips do not show the effects of osmosis. 18. Which of the following best explains why no plasmolyzed cells are observed for the ͲǤͲͷ ‘ŽȀ‰ •—‰ƒ” •‘Ž—–‹‘ǫ F. The concentration of sugar inside the cells is greater than 0.05 mol/kg. G. The concentration of sugar inside the cells is less than 0.05 mol/kg. H. The concentration of sugar inside the cells is greater than 0.55 mol/kg. J. The concentration of sugar inside the cells is less than 0.55 mol/kg.

19. The students identify the same number of plasmolyzed cells in both samples from the onion strips submerged in the 0.55 mol/kg and the 0.45 mol/kg sugar solutions yet calculate a value of “Percentage of Plasmolyzed Cells” of 100% for the 0.55 mol/kg solution but only 78.1% for the 0.45 mol/kg solution. This difference in percentage of plasmolyzed cells is due to the fact that: A. the cells plasmolyzed by the 0.45 mol/ kg solution are less completely depleted than those plasmolyzed by the 0.55 mol/kg solution. B. the students analyzed 50 cells from the onion strip submerged in the 0.55 mol/kg solution and 64 cells from the onion strip submerged in the 0.45 mol/kg solution. C. the 0.55 mol/kg solution acts more vigorously on the onion cells, accelerating the rate of plasmolysis on the cells submerged in that solution. D. all of the cells in the onion strip submerged in the 0.45 mol/kg solution are plasmolyzed but only a portion of those in the onion strip submerged in the 0.55 mol/kg are are plasmolyzed. 20. Which of the following best explains the change in weight of the beet disk before and after submersion in the beaker containing the ͲǤͲͲ ‘ŽȀ‰ •—‰ƒ” •‘Ž—–‹‘ǫ F. The disk is dehydrated, causing it to absorb water while submerged in the solution. G. The disk has a sugar concentration greater than 0.00 mol/kg of water, causing it to absorb water while submerged in the solution due to osmosis. H. The disk has a sugar concentration less than 0.00 mol/kg of water and loses water while submerged in the solution due to osmosis. J. No sugar molecules are available in the 0.00 mol/kg solution to migrate across the semi-permeable membranes of the cells in the beet disk.

GO ON TO THE NEXT PAGE.