Diffusion | Membranes and transport | Biology | Khan Academy
Understanding how particles passively diffuse down their concentration gradient. Watch the next lesson: ...
Answer
What is simple diffusion:
Simple diffusion is basically the diffusion of substances through a membrane without needing the help from other substances, such as proteins. An example would be carbon dioxide gas for plants. When the stomata open, it goes into the plant, as a result of moving from a higher concentration to a region of lower concentration.