Report Abuse. well i know for a fact that osmosis(the diffusion of water) occurs in the body cell, but my biology class defines diffusion as the movement of particles from an area of low concentration to an area of high concentration.Hello · 8 years ago.est Answer: Lots of places. It occurs with (some) nutrients through the intestinal wall, with oxygen and nutrients from capillaries to cells, with neurotransmitters across synapses, with waste in the kidneys, and with oxygen through the lungs and into the blood stream, just to name a few.