• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Experiment Aim: To investigate the effects of placing onion epidermal cells in different solutions.

Extracts from this document...


´╗┐Title: Cell Structure Aim: To investigate the effects of placing onion epidermal cells in different solutions. Apparatus: onion, methylene blue solution, distilled water, petri dish, 0.6 and 0.1 moldm-3 sucrose solution, microscope slides, light microscope, razor blade, knife. Method: A piece of the inner epidermis was removed from an onion scale. Two pieces of the epidermis were cut about 5mm*5mm. the pieces were placed in a small dish covered with methylene blue solution and put aside for 5 minutes. After 5 minutes the pieces of epidermis were removed and washed carefully in a dish. One piece of tissue was mounted in 0.6 moldm-3 sucrose solution on a microscope slide under a cover slip. The slide was then labeled. ...read more.


0.15 0.45 0.40 0.05 5 0.40 0.28 0.12 0.25 0.21 0.04 Discussion: Osmosis is the movement of water molecules down their diffusion gradient, through a partially permeable membrane. When placed in solution water molecules will enter or leave a plant cell through osmosis depending on water potential. The water potential is the tendency for water to a solution. It diffuses out a dilute solution (a lot of water- high water potential) and into concentrated solution ( a lot of solute- low water potential). When a plant cell is placed into a dilute solution which has a greater water potential than it, water enter the cell by osmosis. The cell wall of the plant cell does not directly affect this movement, because it is fully permeable to water and to most of the solute in it. ...read more.


Using the measurements of the dimensions A and B the extent of plasmolysis by each concentration was obtained. This showed how far the contents of the cell moved from the cell wall. A greater extent of plasmolysis occurred in the 1.0 moldm-3 solution than the 0.6 moldm-3 whcich meant it has a greater water potential. More water therefore left the cell in the 1.0 moldm-3 solution than the 0.6 moldm-3. The procedure could have been extended by observing more cells and also by keeping the tissue in longer in the concentrated solution. Conclusion: It can be concluded that the cells in the 1.0 moldm-3 sucrose solution lost more water and therefore became more plasmolysed than the cells in the 0.6 moldm-3 solution. Hence the higher the concentration the greater the extent of plasmolysis in the cells. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Molecules & Cells 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 AS and A Level Molecules & Cells essays

  1. An experiment to find of the isotonic point of root vegetables cells in contents ...

    The trend I spotted with the carrot cylinder was that it's mass, width and length increased in the 0.4 and 0.45 molar sucrose solutions. This is because a higher water potential is present in these solutions and hence the rate of water movement into the cell was greater.

  2. To find out how different concentrations of sucrose solution affect the incipient plasmolysis of ...

    Evaluation Overall, I believe that my experiment went quite well, I achieved reasonably accurate results and can make a clear evaluation from them. All the results follow the same general pattern of a negative correlation. My choice of equipment, which was not brilliant, was suitable for this experiment.

  1. An Experiment to investigate the factors that affect the Power Output of a solar ...

    Some solar cells however, may have more than one electrical field and they operate to free the electrons when light is absorbed. A current is a flow of electrons, and the electric fields create a flow of electrons, and so a current is produced this way.

  2. Experiment to investigate the water potential of potato tissues when immersed in various sucrose ...

    At this point the pressure potential is equal to zero and therefore the water potential is equal to the solute potential: Water potential = solute potential ? = ?s This precise stage in which the ? = ?s is referred to as the point of incipient plasmolysis and the cell is said to have been incipiently plasmolysed.

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