• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month
Page
  1. 1
    1
  2. 2
    2
  3. 3
    3
  4. 4
    4
  5. 5
    5
  6. 6
    6
  7. 7
    7
  8. 8
    8
  9. 9
    9
  10. 10
    10
  11. 11
    11

What effect different solutions, with the same water potential, have on potato and cucumber strips (by mass).

Extracts from this document...

Introduction

Jessica Rossi What effect different solutions, with the same water potential, have on potato and cucumber strips (by mass). Plan Introduction Plants in the soil have their roots in a dilute solution of various mineral ions. Sometimes, the soil they are planted in gets flooded with sea water (which has an average of 0.3 sodium chloride concentration). In these cases the roots are observed to wilt and become flaccid. In my experiment, I will simulate this situation using potato and cucumber strips, placing them in different solutions (sodium chloride, glucose and sucrose) at different molar concentrations. A substance dissolved in water is called a solute. A solvent is a liquid that is able to dissolve another substance, a solute, to form a solution. Water potential is a measure of the ability of a solution to give out water. Water potential (y) can be expressed as the sum of the solute potential (ys) and the pressure potential (yp). (y) = (ys) + (yp) The water potential of pure water is zero and all other solutions have a negative water potential. The greater the solute concentration, the more negative is the value for water potential. Background Information The water content of plants depends on environmental conditions. In land plants, water plays a vital role in structural support and mineral transport, thus, the lack of water may lead to wilting or possibly death. ...read more.

Middle

[image006.jpg] * Place the correct quantity of pure distilled water into a beaker, measured using a different measuring cylinder. * Place all test tubes in test tube rack. * Place 20cm of each solution into each of the test tubes, so that all 30 test tubes will be holding each a different concentration of any solution. * Place 20cm of distilled water in another two test tubes, these will be used as the control in order for the test to be fair. * Cut 16 potato cores and 16 cucumber cores and place them on a ceramic tile. Using a scalpel and ruler (calibrated in millimeters) cut the cores at 50mm, taking care that no peel is left and that all the cores are accurately cut at the nearest millimeter. * The cores will be individually weighed on a top pan balance to an accuracy of 0.01grams. * Each of the cores will then be placed into one of the 32 test tubes for 2 hours, timing kept by a stopwatch. * After 15 hours the cores will be removed from the solutions, blot-dried on top of a filter paper, and weighed straight away. * After the experiment has been completed, all apparatus has to be washed and properly placed away, and all organic material should be disposed of. ...read more.

Conclusion

However, this was impossible to do as 48 plant tissue samples were needed for each vegetable. * A variety of other similar plant roots could have been placed through the same procedure in order for comparison of different tissues. * A larger cucumber should have been used, in order to cut the chips out of the same tissue, and trying to exclude the seeds and placenta, as this could have lead to inaccuracy in the experiment. [image008.jpg] * Some results could have been inaccurate due to not allowing excess solution on the external surface of the cores from draining away before placing it onto the top pan balance. This superficial water would be measured as extra mass by the sensitive weighing scales, even if the cores have been blot-dried on filter paper beforehand. * Once the cells have been plasmolysed, it is possible that some of the solution has entered the cell between the cell wall and the cell membrane, given that the cell wall is fully permeable. This could lead to inaccuracy of results, as part of the mass in the plasmolysed plant cores would be caused by this intake of water, which has not been caused by osmosis. [image010.jpg] * The experiment was also lmited by the accuracy of the top pan balance, which showed mass in grams to one decimal place. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our GCSE Green Plants as Organisms section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related GCSE Green Plants as Organisms essays

  1. Marked by a teacher

    An investigation into the effect of a germination inhibitor on the germination of seeds.

    3 star(s)

    The seeds had had 6 full days to germinate and so the majority in the weaker concentrations had germinated because after the testa has ruptured (mentioned above, it is due to the water absorption) then the process is quite fast.

  2. The effect that different concentrations of salt solution in the water has on strips ...

    But because there are more on one side than the other, there's a steady net flow into the region with fewer water molecules, i.e. into the stronger solution (of salt). This causes the salt rich region to fill up with water.

  1. What effect does the sucrose concentration have on osmosis?

    Also, the scalpel must be used only when the potato is on the white cutting board. It must be used carefully and in close proximity of other people - that way if an accident does occur someone is there to help.

  2. To investigate the effects of using different concentration of Sucrose solutions in Osmosis with ...

    Then the cucumber shall be cut up using the slicer into ten equal pieces. These shall then have their mass recorded, one by one, and keeping track of which slice is which placed in the Petri dishes and left there for 20 minutes.

  1. Investigate the cell sap concentration of solute in a potato chip using osmosis and ...

    be coming out whereas at 0% solution there would be much more going into the chip than going out so its mass would increase by more. The cells in the chips that were put in solution lower than 6% would have become turgid (diagram 2)

  2. Determine the water potential of potato tuber cell with the varying affect of solute ...

    I cannot make a percentage change prediction because I do not know the initial masses of the potatoes yet. For the 0.2 mol dm-3 sucrose solution, I predict that there will again be an increase in mass. However this time due to the increase in concentration, I predict that the change in mass will not be as much.

  1. Experiment to Compare Stomata Density in Different Dicotyledonous

    Then take an average from the results. This is to allow for human error. Preliminary Investigation: findings and adjustments. The only thing that I changed in my method was the use of cover slips instead of using another glass slide to cover the epidermis impression.

  2. Determine the Water Potential of Potato tissue.

    by a nuclear membrane, cytoplasm, rough and smooth endoplasmic reticulum (ER), ribosomes, mitochondria, Golgi apparatus and a large, permanent vacuole. Plant cells always have a strong cell wall surrounding them. When they take up water by osmosis they start to swell, but the cell wall prevents them from bursting.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work