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Question
Two potato cubes each 1 cm3 in size, were placed separately in two containers (A and B), the container A having water and the other (B) containing concentrated sugar solution. After 24 hours when the cubes were examined, those placed in water were found to be firm and had increased slightly in size and those placed in concentrated sugar solution were found to be soft and somewhat decreased in size. Use the above information to answer the questions that follow:
Account for the softness and decrease in size of the potato cubes which were placed in sugar solution.
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Solution
Sugar solution is hypertonic to the potato cells, due to which exosmosis occurs and water flows out of the potato cells. The potato cell loses its distended appearance, the cytoplasm shrinks and the plasma membrane withdraws from the cell wall. The cells become limp or flaccid. This causes the softness and decrease in size of the potato cubes when placed in sugar solution.
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Fill in the Blanks
Osmosis in the diffusion of _______ molecules from the region of higher _____ potential to that of lower potential across a S.P.M.
Multiple Choice Question:
Plasma membrane controls:
