Friday, October 26, 2012

Diffusion (Short Note)

It is the movement of molecules from the area of higher concentration to the area of lower concentration. A few substances freely diffuse across the cell membrane. For example oxygen, carbon dioxide, diffuse in and out of the cells.

Diffusion is an essential step in the biological processes like photosynthesis, respiration etc. During stomatal transpiration, water vapours from the intercellular spaces escape out in the outer atmosphere by this process.

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