Dear student,
Diffusion is the process where particles move from region of their higher concentration to lower concentration
. Diffusion in plants occur during exchange of gases in leaf in the process of photosynthesis.
In photosynthesis, carbon dioxide diffuse into leaf via stomata to the cells (palisade cells).
Oxygen and water vapour produced during photosynthesis diffuses out of leaf in the same way in a process called transpiration.
diffusion in human body occurs across cell membranes, with the cells and tissues. We can find the process of diffusion in the respiratory system. There is a flow of blood between the body and heart. There is diffusion in the kidneys.