21. Three different processes are occurring in the drawing below. Name each process and describe it.

Answer:
Process A is diffusion
- diffusion is the random movement of molecules from the area where there is more of them to an area where there is a few of them without the input of energy.
Process B is facilitated diffusion
- facilitated diffusion is the transport of substances across a cell membrane from an area of higher concentration to a lower concentration with the help of Transport protein
Process C is active transport
- A ctive transport is when an input of energy is required to move materials through a cell membrane .