<p>A cell is soaked in a 15 percent sugar solution and its content soon separated from the cell wall. forming a mass in the center of the cell. All of the following are true EXCEPT:</p>
<p>A. The vacuole lost water and became smaller
B. The space between the cell wall and the cell membrane expanded
C. The large vacuole contained a solution with much lower osmotic pressure than that of the sugar solution
D. The concentration of solutes in the extracellular environment is hypertonic with respect to the cell's interior
E. The sugar solution passed freely through the cell wall but not the cell membrane</p>
<p>The answer is D and it explained that it should be "hypotonic" because water was coming out of the cell. But I thought the concentration of solutes outside was greater than that inside so water was coming out of the cell to balance the concentration? Did I miss something? I am utterly confused right now T^T</p>
<p>And also, do plant cells have lysosomes? I know that it is a highly debatable issue but the practice book I got asked about this. I chose no but the book said yes. I used to learn that plant cells do not have lysosomes but when I googled it, I found out that there is recent evidence suggesting otherwise. I hate it when books ask about controversial stuff.</p>
<p>Yeah, solutions can be confusing. This is how I think of it.</p>
<p>Say you have a cell in a 15% sugar solution. The cell is hypotonic and the solution is hypertonic. However, ONLY WATER can pass through the cell membrane, NOT SUGAR. Because nature will try to achieve equilibrium (when both are equal), water will move from the cell to the outside solution. In proportion to the sugar, water is more highly concentrated in the cell. Because sugar can not enter the cell, water exits the cell. Hopefully that makes sense?</p>
<p>Hmm now that I peruse the answer, I think the wording is pretty much misleading. When talking about tonicity, we usually say “the solution is hypertonic”, not “the concentration is hypertonic”. It is mostly worded as “The concentration is greater than…”. Tonicity is applied to solution, not solutes. </p>
<p>And perhaps mnstrivola has a point. But even so, the original phenomenon would be the sugar solution is hypertonic to the cell right?</p>
<p>No. they can’t “diffuse”… or pass passively…
Dunno about actively…
Anyway. I don’t think it’s the right answer anyway cuz they can’t diffuse across the membrane.</p>