A student takes two epidermal strips from a red rhubarb stalk. She places one strip in distilled water and the second strip in a concentrated sucrose solution. She then uses a microscope to photograph the cells in each treatment as shown in the diagram:
a.[1]
Suggest why red rhubarb is particularly useful when carrying out this investigation.
b.[2]
Explain what is meant by the term osmosis.
c.[4]
Explain why the rhubarb cells in concentrated sucrose solution look different from those placed in distilled water.
d.[2]
When human red blood cells are placed in distilled water, they swell and burst, meaning no intact cells can be seen under the microscope. Explain why this happens to red blood cells, but does not happen to the rhubarb epidermal cells.