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Osmosis and Plant Cells.

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Introduction

David Biagioni Osmosis and Plant Cells. In this experiment I intend to look at how osmosis affects plant cells. The aim of this experiment is to investigate the movement of water into and out of plant cells by osmosis. The cells chosen for study will be potato strips. A definition of osmosis from 'Britannica Encyclopedia' is: "the flow of water by diffusion through a differentially permeable membrane from areas of high water concentration to regions of low water concentration." I plan to investigate this phenomenon using the methods expressed below: My Procedure For this experiment I plan to cut out eighteen thin strips of potatoes of uniform size. I shall measure these out using a vernier calliper and then cut them as accurately as I can, using a scalpel. Now I shall put six test tubes into a test tube rack. I shall label these with sticky labels to show what solutions they shall contain. The solutions I shall use in strength of molars are: 0, 0.2, 0.4, 0.6, 0.8, and 1.0. I shall then measure out the solutions for each test tube using a burette and pied pump. Each test tube shall contain twenty ml of the selected solution. ...read more.

Middle

Length after 1200 seconds in the solution (mm) Increase / Decrease in length (mm) 20ml of 0.0 Molar Sucrose Solution 40.00 41.50mm 1.50 increase 20ml of 0.2 Molar Sucrose Solution 40.00 40.50mm 0.50 increase 20ml of 0.4 Molar Sucrose Solution 40.00 40.74mm 0.74 increase 20ml of 0.6 Molar Sucrose Solution 40.00 36.50mm 3.50 decrease 20ml of 0.8 Molar Sucrose Solution 40.00 36.07mm 3.93decrease 20ml of 1.0 Molar Sucrose Solution 40.00 35.12mm 4.88 decrease Set two of results Solution (Molar) Initial Length of Potato Strip (mm) Length after 1200 seconds in solution (mm) Increase / Decrease in length (mm) 20ml of 0.0 Molar Sucrose Solution 40.00 42.47mm 2.65 increase 20ml of 0.2 Molar Sucrose Solution 40.00 40.69mm 2.50 increase 20ml of 0.4 Molar Sucrose Solution 40.00 40.68mm 1.04 decrease 20ml of 0.6 Molar Sucrose Solution 40.00 36.18mm 1.84 decrease 20ml of 0.8 Molar Sucrose Solution 40.00 35.63mm 3.05 decrease 20ml of 1.0 Molar Sucrose Solution 40.00 36.10mm 4.02 decrease Set 3 of Results Solution (Molar) Initial Length of Potato Strip (mm) Length after 1200 seconds in solution (mm) Increase / Decrease in length (mm) 20ml of 0.0 Molar Sucrose Solution 40.00 41.31 2.65 increase 20ml of 0.2 Molar Sucrose Solution 40.00 40.89 2.50 increase 20ml of 0.4 Molar Sucrose Solution 40.00 40.41 1.04 decrease 20ml of 0.6 Molar ...read more.

Conclusion

This would make it hard to get a correct measurement to decimal points of a millimeter. During the measuring and recording of the results there could have been some lack of accuracy. Due to the fact that the potato chips were not weighed, but just measured so they're mass could have varied indefinitely. I also believe that carrying out the experiment in more controlled conditions would have increased the accuracy in the results. I believe that to gain a set of more accurate results, you would need eighteen people. This many people would be needed so that the potato strips could be measured simultaneously. I also think that using a wider range of concentrations could improve the reliability of the results. This is because there would not be a large space between results, there would a wider range of results and I would predict that these would produce a more accurate set of results and conclusion. To make this experiment and my results more accurate and reliable, there are a few things that I could carry out. These things would be: - Use a wider range of concentrations, to give a wider range of results. If I could do it again I would use 0.05 molar gaps instead. Carry out the experiment in controlled conditions. Ensure an equal starting length and weight for each potato chip. ...read more.

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