Question

Treatment cause the rhubarb cells to be plasmolysed after 5 minutes If an epidermal peel of rhubarb cells (from the edible petiole of the plant) is placed on a microscope slide and immersed in water, then viewed through a light microscope they look like those in panel A. If placed in 1.0M sucrose or 1.0M urea solution the cells become plasmolysed within several minutes and look like those in panel B. The vacuoles of these epidermal cells are full of pigment and take up a large proportion of the cell volume. PANEL A Turgid rhubarb epidermal cells I PANEL B Plasmolysed rhubarb epidermal cells After 1 hour though, urea treated cells return to those like panel A and those in sucrose remain plamolysed Answer the following questions about this osmosis experiment. Question 2 Which molecules crossed the membrane to cause this effect? Which direction was the movement of each molecule? Question 3 In relation to movement across the cell membrane of the two chemicals used in the experiment, how do you explain the difference seen with urea treated cells and sucrose treated cells after one hour? --

Answer 1

of liger Question 2 water molecules crossed the membrane to cause this effect. And the fluid movement occurs from the solution of low osmotic poressure to solution: biqu osmotic pressure. Water Solution of low osmotic pressure → liger 71.0M sucrose 20 M unrea question 3 (hypertonic) finstly the 1.0M & urea solution was lypentonic. So, due to exosmosis, plasmolysis happens. But aften 1 W., dide the conc. of urea is reduced, so, solutiow becomes hypotonic. Maut @ 1.0 M Sucrose solutiow remains lvypentoric aften