"diffusion and osmosis" on our daily life

[binibiningarki06]

hi there.

i am a college student pursuing a degree in architecture. i work part-time as a tutor too.

i would like to ask help for the following questions. i will need to discuss these to my tutee (for her secondary school biology) and my limited knowledge on this topic pointed me on this website.

it's all about how diffusion and osmosis affect our everyday lives. the manual says the answer should come from the knowledge of the principles of diffusion and osmosis. hence, the reason behind the following must be explained:
1. in some restaurants, sliced potatoes are soaked in water before they are fried.
2. you are reading the label of several brands of eye drops and notice that the contents of all the brands are isotonic to body fluids.
3. you are planning to fertilize your lawn. you think to yourself, "if i used more fertilizer, i wouldn't have to do this often." you apply the fertilizer in double the concentration recommended on the label. the grass turns brown and dies.
4. a student performed the following experiment. she added salt to the water in a pot containing tomato plants. after 15 minutes, she observed wilting begin. after 45 minutes wilting was pronounced and the plant was collapsing. after 90 minutes, the plant was severely wilted.

source: worksheets and handouts in biology
school year 2008-2009, Miriam College Quezon City Philippines

any kind of insight will be of great help. i am doing my own web surfing and 'studying' for this particular topic as i type. (multitasking huh?) so i hope nobody gets offended if i post these 'elementary' biology questions in here. (apologies, i didn't take up any biology subject in college.)