Determination of osmotic pressure of cell sap.
Step:
1.Using 1M sucrose solution that is given,prepare a series of solutions that range in conce ntration from 0.1m till 0.9m

2.Into each of the above said solution place a bit of the algal filament that is provided.

3.After 10 minutes of immersion,remove the alga from the test tube and place it on top of a glass slide.put a few drops of the sucrose solution,in which it was immersed,on the alga.

4.Observe under the microscope and choose about 25 cells.Determine the number of cells that are plasmolysed out of the 25 cells.The cells in which the protoplasm appears to have lost contact with the cell wall,even slightly,must be counted.

WARNING

the immersion time is important in this experiment you are advised not to place the algal filaments into the different sucrose solution at the same time. As. such do it one at a time. Also alga must be placed into the next solution just before removing the filaments for observation from the previous test tube.

Question:
Explain the precautions(warning) that are taken while carrying out this experiment and discuss the error may happen through out the experiment.