Answer :
Final answer:
Salad dressing causes lettuce to wilt primarily through osmosis, where water from the lettuce moves into the dressing due to its higher concentration of dissolved solids. This movement of water results in the lettuce losing its turgor pressure and becoming limp. Thus, the main reason is that the lettuce loses some of its water to the salad dressing.
Explanation:
Why Does Salad Dressing Cause Lettuce to Wilt?
Sally's observation about her salad is a common phenomenon that can be understood through the principles of osmosis. When salad dressing, which often contains salt and other dissolved solids, is placed on lettuce, the lettuce enters a process of osmosis due to the difference in solute concentration between the lettuce cells and the dressing.
Here’s what happens:
- The lettuce loses some of its water to the salad dressing: Because the salt and other dissolved solids in the salad dressing create a hypertonic environment (higher concentration of solutes than in the lettuce), water moves out of the lettuce cells to balance the concentration of solutes. This loss of water causes the lettuce to wilt.
- The concentration gradient causes water to move from the area of lower concentration (inside the lettuce) to the area of higher concentration (in the dressing) to achieve equilibrium.
- This movement of water leads to a loss of turgor pressure in the lettuce, which is necessary to keep it crisp and firm.
To illustrate this with a simple example, think of how vegetables can also lose crispness when left in saltwater. The same principle applies here: the excess salt in the dressing pulls moisture out of the lettuce, leading to wilting.
Learn more about osmosis here:
https://brainly.com/question/32297250
