What are the three primary mechanisms by which molecules move across the cell membrane. explain how each mechanism goes with or against the concentration gradient and whether they each use energy.

The three primary mechanisms by which molecules move across the cell membrane are :
- Passive transport, the movement of molecules that does not require energy
- Diffusion,  when molecule move from higher concentration to lower concentration
- Osmosis, when molecule move to higher concentration

hope this helps

Ibelieve its b but u might have to